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Archive for the ‘Epidemiology’ Category

Salmonellosis in Finland 2021: After 450 Cases, How to Prevent the Next Outbreak?

Food safety and quality assessment. Microbiologist testing poultry sample for the presence of salmonella and Escherichia coli,
Image: Microbiologist testing poultry sample for the presence of Salmonella

 

written by Chandana Balasubramanian

About 150 children in Finland and a total of 450 individuals have fallen ill from Salmonella poisoning. Most affected individuals are from daycare centers in the city of Jyväskylä. The cause of this outbreak is suspected to be lettuce imported from Germany via Sweden [1]. Though Salmonella outbreaks have been declining, the 2021 Finland outbreak is one of many reported worldwide this year. As our world continues to shrink due to globalization, it is getting harder for public health agencies to monitor and prevent Salmonella outbreaks from imported foods

This year, Sweden has also reported a national Salmonella outbreak that affected more than 30 people [2]. In June, melons sourced from Costa Rica, Honduras, or Brazil were the most likely cause of a Salmonella outbreak of 200 people across ten countries, including Finland, Denmark, Belgium, Germany, the Netherlands, Sweden, United Kingdom, Canada, and Switzerland [3]. In the United States, the CDC (Centers for Disease Control and Prevention) initiated a ‘Food Safety Alert’ after detecting 102 infected cases across 14 states due to contaminated seafood that originated in Colorado [4]. 

One of the biggest challenges in catching Salmonella in imports is the fact that the bacteria is mainly found in fresh produce and other foods with a short shelf life. This hurdle is made even more complex because of the popular hub-and-spoke model of centralized food distribution. In this model, one country in a region acts as a centralized hub that processes fresh produce, meat, or poultry. This food is then exported to several countries simultaneously. By the time infections are reported, most of the contaminated inventory may have already been consumed – either on its own or mixed with other batches – or thrown away. This makes it difficult to obtain enough samples to test and trace the country of origin [5]. 

 

A History of Salmonellosis in Finland

Let’s take a closer look at Finland. At 9.29 cases per 100,000 population, Finland has the highest rate of Salmonellosis among Nordic countries despite its stringent controls and processes [6]. 

Nordic region Salmonellosis rates per 100000 graph
Image: Salmonellosis rates per 100,000 population for Finland, Sweden, Norway, Iceland, and Denmark. Copyright © GIDEON Informatics, Inc.

 

Before 2021, the biggest Salmonella outbreak in Finland was in 2008. Pre-chopped and ready-to-eat Iceberg lettuce happened to be the prime suspect for the 2008 Salmonella outbreak in Finland. There were 77 confirmed cases, and two elderly patients died [7]. 

 

Image: Salmonellosis in Finland. Cases from 1969 to 2021. Copyright © GIDEON Informatics, Inc.
Image: Salmonellosis in Finland. Cases from 1969 to 2021. Copyright © GIDEON Informatics, Inc.

 

Finland has seen a steady decline in Salmonellosis since 1995, when the country initiated its national Salmonella control program. The Finnish national Salmonella control program (FSCP) mandates regular testing of cattle, poultry, and pigs, including eggs and meat. Lab test results are evaluated by the Finnish Food Agency monthly. There are stringent checks and balances included throughout their entire supply chain. 

The FSCP measures have helped lower the rates of homegrown Salmonella. However, like many other countries, Finland needs a faster and more effective way to monitor and prevent the bacteria from being brought in from other countries, either through travel or cross-border food imports [8]. 

 

List of Prominent Salmonella outbreaks in Finland*: 

  • 1976: 550 cases were reported due to contaminated mayonnaise prepared in Spain and served on four international flights (Las Palmas-Helsinki, Las Palmas-Honover). 
  • 1986: 226 cases from packaged meals offered to train and air passengers. 
  • 1992: 224 cases due to contaminated mung beans.
  • 1994: 210 cases in Southern Finland due to alfalfa seeds.
  • 1995: 242 cases were reported in Finland (and the U.S.) due to alfalfa seeds imported from a Dutch supplier. 
  • 2001 – 2003: 666 cases reported in Norway, Finland, and Swedish tourists infected by contaminated poultry.
      • 2001: 303 cases
      • 2002: 164 cases
      • 2003: 199 cases.
  • 2007: 8,453 cases (almost 30% of the population) due to contaminated water in the town of Nokia, Finland. It is the largest reported water-borne outbreak in Finland [9].   
  • 2008: 107 cases in Newport and Reading, Finland due to contaminated lettuce. 
  • 2015: 122 cases in Finland due to an ice hockey team event in Latvia.
  • 2021: 450 cases due to contaminated lettuce imported from Germany via Sweden. 

*Data sourced from GIDEON – the comprehensive Global Infectious Diseases and Epidemiology Online Network database. The GIDEON platform also lists notable cross-border Salmonellosis events in Finland.

Public health agencies worldwide continue to worry about keeping Salmonellosis cases down in their respective countries. But in this hyper-connected world, it can prove challenging. A comprehensive database such as GIDEON that tracks outbreaks as they happen across the world may be a viable solution. 

 

Image: Salmonella outbreaks worldwide and list of Salmonella outbreaks in Finland. Copyright © GIDEON Informatics, Inc.
Image: Salmonella outbreaks worldwide and list of Salmonella outbreaks in Finland. Copyright © GIDEON Informatics, Inc.

 

 

What is Salmonellosis? What are the Symptoms of Salmonellosis? 

Salmonellosis is the infection acquired from ingesting the zoonotic bacteria Salmonella. The most common way to get Salmonellosis is by eating raw or undercooked meat, eggs, or fruit and vegetables that have not been washed and handled correctly. 

Salmonellosis is highly contagious, and you can get sick from any person, animal, or thing that carries the Salmonella bacteria. The bacteria are transmitted to our mouths from contaminated humans or animals feces fecal-oral transmission). Other risk factors for Salmonella poisoning are travel to high-risk countries with poor sanitation and exposure to birds and reptiles being kept as pets. 

Symptoms of Salmonellosis include: 

  • Diarrhea
  • Stomach cramps
  • Fever

They usually last four to seven days and begin within 12 to 72 hours of consuming the contaminated food [10]. 

 

Image of profile of sick woman having a stomach ache, left side
Image: a woman experiencing stomach cramps

 

How is Salmonella poisoning diagnosed?

Here is where local laboratory test results play a significant role in helping curb the spread of Salmonella. Usually, stool or blood samples are used to test for Salmonella. Once detected, many countries have protocols that require these labs to report positive incidences of Salmonella to approved public health laboratories for serotyping and DNA fingerprinting.

Around the world, we can also enable on-ground clinicians to play a stronger role in identifying Salmonella cases early and preventing its spread. Having access to data on outbreaks as they happen can help public health officials detect the origin of infection much sooner and more effectively.  

 

How To Prevent Salmonellosis? 

Good immunity is the best line of defense against Salmonella. Our natural stomach acid can help fight salmonella poisoning. However, there is a greater risk of infection for those with impaired immune functioning due to: 

  • the overuse of antacids, 
  • effects of antibiotics, 
  • age – infants and the elderly, 
  • pregnant women, and 
  • lowered immunity from chronic illnesses like Irritable Bowel Syndrome (IBS) and other conditions like AIDS, Malarial infections, and more. 

Other ways to minimize the risk of getting Salmonella is to:

  • always wash your hands before you eat, after touching animals, using the toilet, or changing diapers,  
  • clean food preparation areas, and 
  • minimize the intake of raw and uncooked food and meat. If fresh produce is to be consumed raw, then it must be washed thoroughly. 

Note: Foods containing Salmonella do not smell or look different from uncontaminated food. Washing hands and following food safety guidelines is your best bet to mitigate risk.   

 

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References 

[1]  yle, “Imported lettuce confirmed as cause of Jyväskylä salmonella outbreak,” yle.fi, 07 07 2021. [Online]. Available: https://yle.fi/uutiset/osasto/news/imported_lettuce_confirmed_as_cause_of_jyvaskyla_salmonella_outbreak/12010937. [Accessed 10 10 2021].
[2]  GIDEON Database (Global Infectious Diseases and Epidemiology Online Network), “Salmonellosis in Sweden,” GIDEON, 2021.
[3]  FSN, “Large Salmonella outbreak linked to melons,” Food Safety News, 01 06 2021. [Online]. Available: https://www.foodsafetynews.com/2021/06/large-salmonella-outbreak-linked-to-melons/. [Accessed 10 10 2021].
[4]  CDC (Centers for Disease Control and Prevention), “Salmonella Outbreak Linked to Seafood – Food Safety Alert,” CDC, 08 10 2021. [Online]. Available: https://www.cdc.gov/salmonella/thompson-10-21/index.html. [Accessed 10 10 2021].
[5]  K. G. J. A. R. O. M. A. M. E. W. B. Rebecca L. Bell, “Recent and emerging innovations in Salmonella detection: a food and environmental perspective,” Microb Biotechnol. , vol. 9, no. 3, p. 279–292, 2016. 
[6]  GIDEON Database (Global Infectious Diseases and Epidemiology Online Network), “Salmonella in Finland – Country Note,” GIDEON, 2021.
[7]  T. N. S. G. A. S. M. K. R. R.-F. TARU LIENEMANN, ” Iceberg Lettuce as Suggested Source of a Nationwide Outbreak Caused by Two Salmonella Serotypes, Newport and Reading, in Finland in 2008.,” Food Prot, vol. 74, no. 6, p. 1035–1040, 2011. 
[8]  J. R. E. S. J. P. Riitta Maijala, “The efficiency of the Finnish Salmonella Control Programme,” Food Control, vol. 16, no. 8, p. 669, 2005. 
[9]  E. H. M. J. V. M. S. J. L. P. R. E. K. R. V. T. P. I. M. J. H. O. L. J. A. J. H. M.-L. H. L. M. J. M. a. M. K. • J. LAINE, “An extensive gastroenteritis outbreak after drinking-water contamination by sewage effluent, Finland,” Epidemiology and Infection, vol. 139, no. 7, pp. 1105-1113, 2011. 
[10]  Centers for Disease Control and Prevention, “Salmonella Homepage,” CDC, 08 10 2021. [Online]. Available: https://www.cdc.gov/salmonella/index.html. [Accessed 11 10 2021].

 

Mosquito-borne Diseases Dengue, Zika, and Chikungunya in the United States

Close up newborn aedes albopictus mosquito, pest animal, contagion
Image: Newborn Aedes albopictus mosquito

 

written by Chandana Balasubramanian

Aedes aegypti and Aedes albopictus mosquito-borne illnesses are not just tropical diseases anymore

There’s Dengue fever in California and reports of Zika, Dengue, and Chikungunya cases in Florida. West Nile cases are on the rise in the US, with two recent deaths reported in Arizona and Los Angeles. What do they have in common? These diseases are all mosquito-borne diseases transmitted by the Aedes aegypti and Aedes albopictus species of mosquitoes.

The Aedes aegypti mosquito can transmit Dengue, Yellow fever, Zika, Chikungunya, West Nile Virus, and Venezuelan Equine Encephalitis Virus. Aedes albopictus can transmit Dengue, Chikungunya, Yellow fever, West Nile, Zika, Japanese encephalitis, and more.

These cases have been high enough to warrant different states taking action to curb the spread of disease. The first genetically modified mosquitoes were released in Florida early this year, designed to suppress the Aedes aegypti mosquito.

Dengue cases and rates in the United States, GIDEON graph
Image: Dengue cases and rates in the United States, 1930 to 2020. Copyright © GIDEON Informatics Inc.

 

 

Is the spread of infectious disease mosquitoes to non-tropical countries a recent phenomenon? How are epidemiologists and infectious disease specialists monitoring and predicting the spread? How will the introduction of the Aedes family of mosquitoes affect the population of other species of mosquitoes? How exactly are the viruses maintained in the mosquitoes?

GIDEON Informatics partnered with virologist Dr. Melissa K. Jones at the University of Florida to investigate. Dr. Jones recently moderated an informative webinar on the invasion of the Aedes mosquitoes in the United States, particularly Florida. Experts on the panel were:

  • Guy Hendrickx: Co-founder AVIA-GIS, a Belgian organization focused on spatial mapping and modeling of various topics, including infectious diseases.
  • Stephen Berger MD: experienced practicing physician, infectious diseases specialist, and co-founder of GIDEON, the comprehensive infectious disease database.

 

Highlights from the webinar

Drs. Hendrickx, Berger, and Jones had a fascinating conversation about Aedes-borne diseases. They began by discussing the spread of the Aedes family of mosquitoes away from its traditional habitat in South and Southeast Asia.

Spread of Aedes Away from the Tropics

  • Politics Makes Strange Bedfellows and Infectious Diseases: Did you know that changing political alliances in the 1960s helped introduce the Aedes albopictus mosquito (also known as the Tiger mosquito) to Europe? In the 1960s, an alliance between China and the former USSR ended. However, Albania, a highly communist country in Europe, continued its ties with China. As a result, they frequently imported equipment from China in containers that also carried an unwanted visitor – the Tiger mosquito. Luckily, as Albania did not permit much travel in and out of the country, the mosquito was contained.
  • The Side-effects of Globalization: The Aedes mosquito first entered the United States in the 1980s due to tire imports from Japan. As Europe began imports from Japan in the 1990s, the mosquito began to spread there as well.

Modeling and Tracking the Spread of Aedes-borne diseases

Dr. Hendrickx shared several significant studies about the spread of mosquito-borne vectors and how his team has been instrumental in tracking and predicting the spread of the Tiger mosquito. He stressed that studying the import of vector-borne diseases is essential to help curb outbreaks.

Comparing Clinical Features of Mosquito-Borne Diseases

Dr. Stephen Berger discussed how it might surprise people to know that mosquito-borne diseases are more common in the United States than people may think. After all, the most common condition affecting all American Presidents is not heart attacks or cancer, but malaria! Even more surprising, almost all (except two) got their malaria within the United States, not from another country.

Dr. Berger stressed the importance of clinicians conducting differential diagnoses to compare clinical symptoms and identify mosquito-borne diseases early. This way, a country can curb import-based outbreaks.

Dr. Berger used the GIDEON differential diagnosis web app for a demonstration. He showed how adding ‘insect bites’ to a list of symptoms can help clinicians narrow down potential diagnoses to arrive at the most probable one.

 

Image: GIDEON differential diagnosis of mosquito-borne illnesses in the United States. List ranked by probability based on symptoms. Copyright @ GIDEON Informatics Inc.
Image: GIDEON differential diagnosis of mosquito-borne illnesses in the United States. The list is ranked by statistical probability. Copyright @ GIDEON Informatics Inc.

 

 

The Need for More Data-Driven Research on Mosquito-Borne Diseases

West Nile virus is one of the most severe mosquito-borne diseases that Dr. Berger treats. He mentioned that West Nile is more common in adults than in children. However, he also stressed that there is still an excellent opportunity for further research on several topics. For example, is West Nile more common in adults solely due to physiology? Or are there social factors – for example, children may not be allowed out at night? This may reduce their exposure to the virus.

 

West Nile Fever outbreaks map, 1955 to 2020
Image: West Nile Fever World Outbreak Map, 1955 to 2020. Copyright © GIDEON Informatics Inc.

 

 

Similarly, St. Louis encephalitis can even be fatal for adults, but children are mainly unaffected. Why is this so? More research in this field can offer greater insight.

Dr. Jones and the panel also discussed the challenges and industry best practices to curb the import and export of vector-borne diseases at different ports of entry.

For more, please watch the GIDEON, Avia-GIS, and the University of Florida collaborative webinar on the Invasive Aedes Mosquitoes: Dengue, Chikungunya, and Zika risks in Florida and the United States.

 

 

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New Tetanus Cases Reported. What to Do About This Deadly Infection?

PATHOGEN OF THE MONTH: CLOSTRIDIUM TETANI

Tetanus is an infectious disease caused by the pathogenic bacteria Clostridium tetani
Image: 3D illustration of Clostridium tetani, the agent of Tetanus

 

written by Chandana Balasubramanian

There’s an urban legend about Tetanus shots. Many people feel you need them only when you step on a rusty nail or if a splinter pokes you. Like any good myth, there is a tiny bit of truth attached to it. Yes, stepping on a nail is a good reason to get a Tetanus shot – but not because of the rust. Once your skin barrier is ruptured, Tetanus bacterial spores from contaminated items can easily enter your body.

The truth is there are many ways to get Tetanus. Spores of the bacteria that cause Tetanus, Clostridium tetani, are commonly found in the soil, dust, and intestines, and feces of several household animals and herbivores, and even humans. However, it does not spread from one person to another. The best way to control Tetanus infections is to prevent them from occurring entirely.

 

Tetanus Epidemiology: Recent and Older Outbreaks

Worldwide, Tetanus cases have declined rapidly due to mass immunization drives by various governments and public health agencies. However, Russia recently reported its first case of Tetanus in nearly two decades in September 2021 [1]. In India, a 12-year-old boy recently survived a severe case of Tetanus [2]. He had not been vaccinated against it. In Northern Kazakhstan, a 53-year-old man died due to Tetanus, and it is not known if he was vaccinated [3].

One potential reason for these new reports of this highly preventable infection is COVID-19.  In July 2020, WHO and UNICEF warned of disruptions to life-saving immunization services across the world due to the pandemic. Healthcare workers and social workers have been unable to follow standard vaccination schedules for many reasons, including:

  • Lockdowns and social distancing,
  • Disruption to transportation,
  • Fear or reluctance to visit hospitals or clinics for non-urgent health services,
  • More healthcare workers diverted towards COVID-19 and emergency services, and
  • A lower number of available auxiliary nursing midwives (ANMs) to drive regional vaccination for children.

Before the pandemic, two notable Tetanus outbreaks occurred in Indonesia during the devastating tsunami in 2005 and an earthquake in 2006. People hurt in disasters are, in general, at a much higher risk of getting infected with Tetanus. In certain parts of Indonesia, a lack of adequate transportation, access to health facilities, and awareness about Tetanus protocols led to many people dying from Tetanus. Another instance of a Tetanus outbreak was after the 2005 earthquake that struck Pakistan [4].

 

Tetanus worldwide cases and rates
Image: Worldwide Tetanus cases and rates, 1980 to 2020. Copyright © GIDEON Informatics, Inc.

 

What Causes Tetanus? What are the Symptoms of Tetanus?

Tetanus is one of the deadliest microbial toxins. It is caused by the bacteria Clostridium tetani and has a high fatality rate. Approximately 10-20% of cases are fatal.

Tetanus is also commonly known as lockjaw. Spores of the bacterium, Clostridium tetani, enter our bodies and spread all over the central nervous system. The spores produce a toxin called tetanospasmin that blocks nerve signals from the spinal cord to the rest of the muscles. The condition is also commonly known as lockjaw because it often causes muscle spasms in the jaw and neck, though it may spread to the rest of the body.

Other symptoms are fever, sweats, a rise in blood pressure, and an elevated heart rate. A common complication of Tetanus is when vocal cords begin to spasm, causing breathing difficulties. Infected individuals can also break their bones or spines based on the severity and frequency of convulsions caused by Tetanus [5].

 

About Clostridium Tetani

Tetanus spores cannot be killed easily. They are found everywhere and can resist extreme conditions like high heat and strong disinfectants. They can remain inactive but infectious for more than 40 years.

Clostridium tetani is an anaerobic bacterium; it does not live or grow in the presence of oxygen. As a result, there is a higher risk of infection with injury sites that do not receive a strong oxygen supply. This includes deep wounds, burns, needle punctures, and surgical procedures performed without adequate hygiene protocols.

While a Tetanus infection can have serious effects, it is now rare in most developed countries. The United States reports an average of 20 cases per year, mostly in unvaccinated individuals. Though most cases are found in developing countries, many of them now maintain rigorous vaccination programs and made great strides in eliminating or minimizing the incidence of Tetanus. Anyone can get infected, but children and newborns are the most susceptible.

 

Image: Clostridium tetani. Anatomy of the cell with terminal spore, and vegetative cell. Structure of the terminal spore: core, cortex, and spore coat.
Image: Clostridium tetani. Anatomy of the cell with terminal spore, and vegetative cell. Structure of the terminal spore: core, cortex, and spore coat.

 

What is the Incubation Period for Tetanus?

The incubation period for Tetanus is anywhere from three to twenty-one days, with an average of ten days. The incubation period varies based on how far the injury site is from the central nervous system. Symptoms can last for weeks and even months. They are higher in unvaccinated individuals and older people for whom immunity is lowered.

Is there a Cure for Tetanus?

There is no cure for Tetanus, but the Tetanus vaccine is highly effective in preventing infection. Once infected, however, symptoms are managed until the effects of the toxin diminish. Chances of survival are lower if muscle spasms develop within five days of getting infected.

There are no blood or laboratory tests to diagnose Tetanus. The most common initial symptom is ‘trismus’ or lockjaw due to facial muscle spasms.

Tetanus can be confused with certain other conditions, which makes it more important to educate frontline clinicians about confirming their own initial assessments either with experts or a platform like GIDEON that factors epidemiology data into differential diagnosis.

How to Treat Tetanus?

Tetanus is considered a medical emergency, and hospital care is required. Treatment is often medication called Tetanus Immune Globulin (TIG), also known as Tetanus antitoxin. It is usually administered as a preventive measure for high-risk wounds and injuries. It is also part of the treatment protocol, together with muscle relaxants and antibiotics like penicillin. When required, proper wound cleaning and debridement are also essential to minimize the risk of Tetanus infections. Patients with difficulty swallowing may also need a breathing tube or ventilator [6].

Preventing the Rise of Tetanus Infections

The best prevention is to ensure newborns, children, and adults receive their Tetanus vaccine doses according to the recommended schedule.

Vaccines for Tetanus are often combined with those for other diseases:

  • DT Vaccines: Diphtheria and Tetanus
  • DTaP or DTP Vaccine: Diphtheria, Tetanus, and Pertussis (whooping cough)
  • Td Vaccine: Tetanus and Diphtheria
  • Tetanus Immune Globulin (TIG)

It is important to note that Tetanus vaccines do not offer lifetime immunity. Many people may need booster shots to continue receiving protection against Clostridium tetani. Additionally, building awareness about improved infection control measures for childbirth, surgery, and other medical protocols in developing and under-resourced nations can make a difference.

 

WHO-UNICEF estimated vaccine coverage of Tetanus
Image: WHO-UNICEF estimated vaccine coverage of Tetanus graph, 1980 – 2019. Copyright © GIDEON Informatics, Inc.

 

References

[1] Outbreak News Today, “Russia: First Tetanus case reported in Sverdlovsk in nearly two decades,” 19 09 2021. [Online]. Available: http://outbreaknewstoday.com/russia-first-Tetanus-case-reported-in-sverdlovsk-in-nearly-two-decades-59531/. [Accessed 29 09 2021].
[2] Times of India, “12-yr-old with rare Tetanus survives at GMCH after 37 days on ventilator,” 17 09 2021. [Online]. Available: https://timesofindia.indiatimes.com/city/nagpur/12-yr-old-with-rare-Tetanus-survives-at-gmch-after-37-days-on-ventilator/articleshow/86272149.cms. [Accessed 29 09 2021].
[3] Outbreak News Today, “Tetanus death reported in Northern Kazakhstan,” 4 09 2021. [Online]. Available: http://outbreaknewstoday.com/Tetanus-death-reported-in-northern-kazakhstan-99534/. [Accessed 09 29 2021].
[4] New York Times, “Twenty-two Tetanus deaths reported in Pakistan quake zone,” NY Times, 27 10 2005. [Online]. Available: https://www.nytimes.com/2005/10/27/world/asia/twentytwo-Tetanus-deaths-reported-in-pakistan-quake-zone.html. [Accessed 29 09 2021].
[5] H. Bjørnar, “Tetanus: pathophysiology, treatment, and the possibility of using botulinum toxin against Tetanus-induced rigidity and spasms.,” Toxins (Basel), vol. 5, no. 1, pp. 73-83, 2013.
[6] Centers for Disease Control and Prevention, “Tetanus for Clinicians,” CDC, [Online]. Available: https://www.cdc.gov/Tetanus/clinicians.html. [Accessed 29 09 2021].

 

 

Lymphatic Filariasis: Everything You Need To Know About This Neglected Tropical Disease

Image: Brugia malayi in blood, a roundworm nematode, one of the causative agents of lymphatic filariasis, 3D illustration showing the presence of sheath around the worm and two non-continuous nuclei in the tail
Image: Brugia malayi in blood, a roundworm nematode, one of the causative agents of lymphatic filariasis, 3D illustration showing the presence of sheath around the worm and two non-continuous nuclei in the tail

 

written by Chandana Balasubramanian

 

Lymphatic Filariasis, commonly known as Elephantiasis, is considered a Neglected Tropical Disease (NTD). This is unfortunate because it is the second leading cause of permanent and long-term disability in the world! [1] As of 2019, it continues to be a threat to over 859 million people in over 70 countries. 

Like other Neglected Tropical Diseases, it is endemic to low-income regions of the globe that deal with poor water quality, sanitation, and limited access to healthcare. India accounts for 47% of chronic Filariasis and 39% of the at-risk population [2]. The good news is that it is considered “potentially eradicable” and can be prevented through timely treatment. Disease spread can be controlled through mosquito control measures [3]. 

But what is this disease? What are the different types of Lymphatic Filariasis? Where is it found? How do we treat it? 

 

What is Lymphatic Filariasis? 

Lymphatic Filariasis is an infectious tropical disease caused by parasitic roundworms (nematodes) transmitted by mosquitoes. The disease is named after the family of worms, Filariodidea.  

The disease affects the lymphatic system – the intricate network in our body that is an integral part of our circulatory and immune systems. It can cause severe swelling and disfigurement; body parts may swell up to abnormal proportions. 

Because of the resulting disfigurement and pain, people suffering from Lymphatic Filariasis often face social isolation and loss of income, leading to mental health issues and greater poverty. 

In recent years, the World Health Organization (WHO) and high-risk countries, have organized mass treatment of all eligible people against Lymphatic Filariasis. This type of preventable chemotherapy has successfully proven to help stop the spread of infection [4].  

 

What are the types of Lymphatic Filariasis? 

There are three types of Lymphatic Filariasis based on the type of pathogen that causes the disease – Bancroftian, Brugia malayi, and Brugia timori.

1. Bancroftian Lymphatic Filariasis

Bancroftian Lymphatic Filariasis comprises 90% of all lymphatic filariasis cases around the world. It is caused by a worm called the Wuchereria bancrofti (W. bancrofti). The earliest descriptions of Bancroftian Filariasis dates as far back as 600 B.C. in India! The disease is named after the dynamic father-son duo of eminent Australian doctors and parasitologists Dr. Joseph Bancroft and Dr. Thomas Bancroft. 

The W.bancrofti worm needs two hosts to complete its life cycle. It sexually reproduces in humans and matures in Anopheles mosquitoes. This has a long incubation period of anywhere from 5 – 18 months, making it harder to detect early without preventive care in high-risk areas.

 

Image: Advanced Elephantiasis - a patient in the Philippines
Image: Advanced Elephantiasis – a patient in the Philippines

 

2. Brugia malayi

The Brugia malayi is a type of roundworm that relies on Mansonia and Aedes mosquitoes as vectors. The adult worms that grow in a human’s lymphatic system are similar but smaller to the W.bancrofti. Human infection often includes swollen lymphatics of the neck, groin, or axilla. 

Brugia malayi is endemic to South and Southeast Asia. It usually takes many bites from mosquitoes carrying the Brugia malayi pathogen before a human can be infected. This is why high-risk countries need to improve their sanitation and water quality standards. Additionally, they need to periodically perform proactive mass drug treatments proven to be effective against Lymphatic Filariasis. 

3. Brugia Timori

Brugia timori is a roundworm that uses the Anopheles mosquito as its vector. The life cycle of this worm is similar to the W.bancrofti and Brugia malayi. The prevalence of this variety of Lymphatic Filariasis is much less compared to the other two. It is usually limited to Timor and the Lesser Sunda archipelago of southeast Indonesia [5]. 

A review of Brugia timori on the GIDEON (Global Infectious Diseases and Epidemiology Online Network) database shows that the number of people infected by Brugia timori is estimated to be less than 800,000. 

There are many similarities in symptoms of the three types of Lymphatic Filariasis, but differences do exist. Below is a dynamic comparison chart generated by the GIDEON platform for symptoms of W.bancrofti, Brugia malayi, and Brugia timori infections.

 

Comparison chart for clinical findings related to Bancroftian, Brugia malayi, and Brugia timori Lymphatic Filariasis. Copyright © GIDEON Informatics, Inc.
Image: Comparison chart for clinical findings related to Bancroftian, Brugia malayi, and Brugia timori Lymphatic Filariasis. Copyright © GIDEON Informatics, Inc.

 

What is the Best Treatment for Lymphatic Filariasis?  

Treatment for Lymphatic Filariasis is concentrated around large-scale chemotherapy known as mass drug administration (MDA). WHO recommends an annual dose of preventive chemotherapy drugs to high-risk populations:

  • Albendazole (400 mg) alone twice per year for areas co-endemic with loiasis
  • Ivermectin (200 mcg/kg) with albendazole (400 mg) in countries with onchocerciasis
  • Diethylcarbamazine citrate (DEC) (6 mg/kg) and albendazole (400 mg) in countries without onchocerciasis [4]. The United States falls in this category. 

In countries without onchocerciasis (river blindness, another type of Filariasis), WHO also recommends ivermectin (200 mcg/kg) together with diethylcarbamazine citrate (DEC) (6 mg/kg) and albendazole (400 mg) in certain settings. 

A graph illustrating the number of people targeted for mass drug administration (MDA) for Filariasis worldwide.
Image: The global number of people targeted for mass drug administration (MDA) for Filariasis. Copyright © GIDEON Informatics, Inc.

 

Some studies have shown that Doxycycline administered over six weeks significantly improved the severity of Lymphatic Filariasis in patients with and without active infection. Doxycycline worked to revert or halt the progression of early stages of Lymphatic Filariasis (1-3), not later ones [6]. Doxycycline is an antibiotic often touted as a ‘wonder drug’ because it can kill various pathogens in situations where other antibiotics may fail, like for malaria and against Yersinia pestis, the bacteria responsible for the Plague. The effects of Doxycycline last for a while, so it is effective for both treatment and prevention. 

 

Image: A graph illustrating countries enrolled on mass treatment programs for Filariasis
Image: A graph illustrating countries enrolled on mass treatment programs for Filariasis. Copyright © GIDEON Informatics, Inc.

 

How to Prevent the Spread of Lymphatic Filariasis? 

Apart from MDA methods, stringent vector control is essential to eliminate or reduce the incidence of Lymphatic Filariasis. Studies show that vector control after MDA is extremely effective in reducing the resurgence of the disease and preventing spread. Vector control includes bed nets and the regular spraying of insecticides to prevent mosquito bites [7]. 

Additionally, more researchers are beginning to incorporate the epidemiological impact of infectious diseases in their studies. For example, over 20 research papers used GIDEON epidemiology data on infectious diseases as part of their parasitology-focused papers in the past three years alone. This is a welcome trend that can raise awareness about neglected tropical diseases, preventive measures and help drive much-needed resources towards mitigating the devastating effects of these parasites. 

 

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References

[1]  CDC (Centers for Disease Control and Prevention), “Hygiene-related diseases: Lymphatic Filariasis,” 2 08 2016. [Online]. Available: https://www.cdc.gov/healthywater/hygiene/disease/lymphatic_filariasis.html. [Accessed 15 09 2021].
[2]  GIDEON Database (Global Infectious Diseases and Epidemiology Online Network), “Filariasis – Bancroftian worldwide distribution,” GIDEON Informatics, Inc, 2021.
[3]  PAHO (Pan American Health Organization), “Paho.org,” PAHO, [Online]. Available: https://www.paho.org/en/topics/lymphatic-filariasis. [Accessed 15 09 2021].
[4]  WHO (World Health Organization), “who.int,” WHO, 18 05 2021. [Online]. Available: https://www.who.int/news-room/fact-sheets/detail/lymphatic-filariasis. [Accessed 15 09 2021].
[5]  P. Fischer, T. Supali and R. M. Maizels, “Lymphatic filariasis and Brugia timori: prospects for elimination,” Trends Parasitol, vol. 20, no. 8, pp. 351-5, 2004. 
[6]  S. Mand, A. Y. Debrah, U. Klarman, L. Batsa, Y. Marfo-Debrekyei, A. Kwarteng, S. Specht, A. Belda-Domene, R. Fimmers, M. Taylor, O. Adjei and A. Hoerauf, “Doxycycline Improves Filarial Lymphedema Independent of Active Filarial Infection: A Randomized Controlled Trial,” Clin Infect Dis., vol. 55, no. 5, p. 621–630, 2012. 
[7]  E. L. Davis, J. Prada, L. J. Reimer and T. D. Hollingsworth, “Modelling the Impact of Vector Control on Lymphatic Filariasis Programs: Current Approaches and Limitations,” Clinical Infectious Diseases, vol. 72, no. Supplement_3, p. S152–S157, 2021. 

Epidemiology Terms Explained: Incidence, Prevalence, Seroprevalence, Morbidity, Mortality, Outbreaks, Epidemics, and Pandemics

Abstract word cloud for Epidemiology with related tags and terms

Written by Chandana Balasubramanian

 

Whether you are a student of nursing, health sciences, public health, or another specialty, you may be interested in expanding your knowledge of epidemiology. Today, the study of infectious diseases is not limited to specialists in the field or researchers. This is because, in our ever-shrinking world, an emerging disease can turn from a small outbreak in one country to a global pandemic in a few weeks. Additionally, shrinking forests and greater urbanization increase the risk of zoonotic transmission of pathogens (transfer of an infectious virus or bacteria to humans from animals). 

Understanding the spread of diseases and epidemiological data can help clinicians and nurses detect and curtail infections early, and public health and government agencies prevent the spread of emerging infectious diseases on their shores.  

Here are the most common epidemiological metrics to help you get started.

 

Incidence

Incidence refers to the probability of a disease occurring in a given population in a specific time period. The incidence measures new cases that develop or are diagnosed in a month or a year. 

For example, compare the two GIDEON maps below color-coded based on incidence. The first map is an outbreak map for the plague and the second is that for SARS-COV-2 or COVID-19. Between the two, even at first glance, we can identify the higher incidence of COVID-19 versus the current endemicity of the Plague.

 

Plague global outbreaks map, illustrating disease incidence between the years 1348 to 2021. Copyright © GIDEON Informatics, Inc
Plague global outbreaks map, years 1348 to 2021. Copyright © GIDEON Informatics, Inc.

 

 

 

Image: COVID-19 global outbreaks map, illustrating disease incidence between the years 2019 to 2021. Copyright © GIDEON Informatics, Inc.
Image: COVID-19 global outbreaks map, years 2019 to 2021. Copyright © GIDEON Informatics, Inc.

 

Prevalence

Prevalence includes all the people who suffer from a specific condition in a population during a specified period. 

Incidence Versus Prevalence

Incidence refers to newly developed cases of a disease or illness within a specific time frame, while prevalence tells us the total number of individuals who are living with it. 

Let’s look at infections from COVID-19 (SARS-COV-2) as an example. In December 2019, when the first outbreak happened, incidence and prevalence numbers worldwide were low. By March 2020, incidence numbers (newly diagnosed cases) were high. Global prevalence numbers were still low because the virus hadn’t spread to the larger population as yet. But by July 2021, due to highly infectious variants, worldwide incidence and prevalence numbers were high. 

Seroprevalence

Seroprevalence refers to the number of people in a population who test positive antibodies to a pathogen (infectious virus or bacteria). Seroprevalence to an antibody to a virus or pathogen can give us an idea of the number of people infected with the virus. 

Seroprevalence is expressed as the percentage of people with antibodies to an infectious agent. 

Seroprevalence Survey or Serosurvey

A seroprevalence survey involves blood serum testing of a population and monitoring whether a particular substance is present or absent. These seroprevalence surveys can be tailored based on how widespread or localized infection is. These studies help public health officials and epidemiologists understand how an infectious agent or pathogen is spreading across a specific population over time. 

 

Image: COVID-19 United States Seroprevalence studies list screenshot, Country Note from GIDEON database. Copyright © GIDEON Informatics, Inc.
Image: COVID-19 United States Seroprevalence studies list screenshot, Country Note from GIDEON database. Copyright © GIDEON Informatics, Inc.

 

***

Morbidity Rate

Morbidity means disease. Morbidity Rate measures how often a specific disease or illness occurs in a given population and includes acute and chronic conditions. The metric is used by public health officials, governments, healthcare systems, epidemiologists, and many more to estimate the overall health of a given population. A higher morbidity proportion indicates a greater number of people suffering from illnesses or diseases.  

The Morbidity Rate is expressed as a percentage of the number of cases of a specific disease or condition in a given population. 

 

Image: Anthrax (Bacillus Anthracis) annual cases in the United States, 1930 - 2020. GIDEON database. Copyright © GIDEON Informatics, Inc
Image: Anthrax (Bacillus anthracis) annual cases in the United States, 1930 – 2020. Copyright © GIDEON Informatics, Inc.

 

 

Attack Rate (AR) or Incidence Proportion

The Attack Rate measures the proportion of people who develop a specific condition or illness in a population that was initially free from that disease or illness. This metric is commonly used in epidemiology to track disease outbreaks. Public health officials use the metric to estimate how many individuals may be infected during an outbreak, epidemic, or pandemic. 

The Attack Rate or Incidence Proportion is calculated as the number of new cases of an infection in the total at-risk population. It is expressed as a percentage. 

Secondary Attack Rate (SAR)

The Secondary Attack Rate estimates the spread of infection from an individual to people in their household, residential area, or to another specified group of people who are at risk of getting infected (like hospital staff). SAR is an important metric during contact tracing for infectious diseases.   

Just like the Attack Rate, the Secondary Attack Rate is expressed as a percentage. It is the number of new cases of an infection developed among a person’s contacts out of their total number of contacts. 

Incidence Rate (IR) or Incidence Density Rate or Person-Time Incidence Rate

Incidence rate measures the number of new cases of a disease occurring in a given population during a specified timeframe. 

Incidence Rate is often expressed as the number of new cases per 100,000 population. 

 

***

Mortality Rate (MR)

Mortality refers to death. The Mortality Rate or Death Rate helps us understand how frequently death occurs in a given population in a specific amount of time. 

The metric is expressed as deaths per 1,000 individuals per year or 100,000 individuals per year. 

 

Image: Dengue Mortality Rates for India, GIDEON screenshot. Copyright © GIDEON Informatics, Inc.
Image: Dengue Mortality Rates for India, 1991 – 2020. Copyright © GIDEON Informatics, Inc.

 

Crude Mortality Rate

Crude Mortality Rate measures the total number of deaths in a population during a specific period of time. It is called ‘crude’ because the number includes all deaths and is used to provide a high-level estimate of deaths during a humanitarian crisis. 

It can be expressed as deaths per 1,000 or 100,000 individuals per year. 

Case-fatality Rate (CFR) or Case-fatality Proportion

The case-fatality rate is used to understand the severity of a disease, evaluate new therapies, and predict how a disease will continue to affect a given population. It estimates the percentage of individuals who die from a specific disease among all people diagnosed with the disease for a given period. It is best applicable for diseases that have specific starts and stops, like acute infections or outbreaks. In reality, it is not a rate but the proportion of deaths due to a specific disease condition. 

It is expressed as a percentage. A higher percentage indicates greater disease severity due to more deaths from the disease. 

Cause-Specific Mortality Rate

Cause-specific Mortality Rate is the number of deaths from a particular cause in a population during a given time interval (usually a calendar year). 

It is expressed as deaths per 100,000 individuals. 

Note: It is different from the case-fatality rate which is not exactly a rate but a proportion of deaths in a population from a particular disease. 

Age-Specific Mortality Rate

The Age-specific Mortality Rate gives us the mortality rate for a specific age group of individuals in a given population. It is also often known as the age-adjusted mortality rate. It is the best way to understand diseases that are highly influenced by age and their impact on a population. This metric is commonly used to understand the rates of heart disease conditions, strokes, diabetes, cancer, and more in a population. 

Age-specific mortality is expressed as deaths per 100,000 in an age range.  

Maternal Mortality Rate (MMR)

The Maternal Mortality Rate is a ratio that helps us understand how many women die from pregnancy-related complications in a population. It is the number of maternal deaths by the total number of live births in a given period. 

The MMR is an important health indicator for a country or a given population because most pregnancy-related deaths are preventable. The biggest pregnancy-related complications include bleeding after childbirth, infections, high blood pressure during pregnancy, and issues that arise during delivery. 

MMR is expressed as deaths per 100,000 live births. 

Infant Mortality Rate (IMR)

The Infant Mortality Rate measures the probability of a child born in a specific period of time dying before it turns one. It helps us understand the likelihood of a newly born infant surviving in a particular population. Since the probability of survival is closely linked to the social structures, economic, and health conditions of a country, it is often a significant indicator of a nation’s health.

It is expressed as deaths per 1,000 live births. 

***

Endemic

The term endemic is used to refer to anything that naturally occurs and is confined to a particular location, region, country, or population. For example, from the malaria outbreak map below, we can see that chloroquine-resistant malarial strains are endemic to certain regions in South Asia, Africa, and South America. 

Image: Malaria - current endemicity and historical outbreaks map, illustrating disease incidence between 1866 - 2021. Copyright © GIDEON Informatics, Inc.
Image: Malaria – current endemicity and historical outbreaks map. Copyright © GIDEON Informatics, Inc.

Epidemic

An epidemic affects many people at the same time. In an epidemic, there is a sudden increase in disease infections that spreads in a region or locality where the disease condition is not naturally found. 

Outbreak

An outbreak is a sudden increase in the number of people infected by or diagnosed with a specific disease condition. It is similar to an epidemic but usually restricted to a much smaller locality or geographic location. 

Pandemic

A pandemic is an epidemic that has spread to several countries or continents. It usually affects a much larger group of people than an epidemic. 

 

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Recent Anthrax Infections: All You Need to Know About the Deadly Bacillus Anthracis

PATHOGEN OF THE MONTH: BACILLUS ANTHRACIS

Image: Bacillus anthracis, a gram-positive spore-forming bacteria that causes Anthrax
Image: Bacillus anthracis, a gram-positive spore-forming bacteria that causes Anthrax

 

written by Chandana Balasubramanian

Trends from past decades can be delightful when they return to inspire today’s music, fashion, and art. However, recently, a dangerous blast from the past reared its ugly head. In early August 2021, China reported a case of the deadly Anthrax pneumonia – its first case after ten years [1]. A few weeks later, local health authorities in another Chinese province discovered nine suspected cases of Anthrax [2]. Around the same time, Russia confirmed a case of Anthrax with a cutaneous infection in a patient involved in butchering cattle meat [3]. 

It’s time to pay more attention to these small outbreaks. 

 

Anthrax Infections Can Be Serious


While these reported incidents seem to have been related to interactions with domesticated animals, Anthrax has been used as a deadly weapon for more than a hundred years. 

One of the most well-known instances of Anthrax used as a biothreat was in the United States, right after the 9/11 attacks of 2001. Five Americans died, and 17 were severely infected when contaminated letters lined with Anthrax were mailed through the U.S. postal service to senators and members of the media. In response, the Federal Bureau of Investigation or FBI launched ‘Amerithrax’- one of the biggest and most complicated investigations in U.S. history. After conducting more than 10,000 interviews on many continents and collecting over 5,730 environmental samples, they found their suspect. 

Understanding the epidemiology, cross-border transmissions, and the history of this zoonotic pathogen is essential to help encourage safe practices when handling livestock and avert potential threats.

 

Bacillus Anthracis Infections Are Not Contagious but Serious

Anthrax is caused by the gram-positive bacteria Bacillus Anthracis. The infection is not spread rapidly from person to person through the air like the flu or cold. It can, however, cause severe illness in domestic animals and humans if they interact with infected animals or contaminated animal products. 

The most common natural way people get a Bacillus Anthracis infection is cutaneous, after skin contact with contaminated meat, wool, or leather from infected animals. Cutaneous Anthrax infection can be transferred from one person to another through open lesions. Another form of infection is gastrointestinal Anthrax which is contracted when raw or undercooked contaminated meat is ingested. The most harmful method of Anthrax infection is through inhalation, by breathing in bacterial spores in the air. It is fatal unless treated immediately. 

Inhalation of Bacillus Anthracis spores is not common in nature. Still, this method has been exploited throughout history for bioterrorism purposes. Bacillus Anthracis infections have affected almost every corner of the globe.  

Image: World map of Bacillus Anthracis outbreaks, 1770-2021. Copyright © GIDEON Informatics, Inc.
Image: World map of Bacillus Anthracis outbreaks, 1770-2021. Copyright © GIDEON Informatics, Inc.

 

Bacillus Anthracis: A Dark History of Bioterrorism

Bacillus Anthracis is effective as a weapon primarily because of its spores. In nature, an infected host sheds the spores on the ground, which then multiply on contact with air. These spores can stay dormant for years, even decades, in the soil waiting for another host [4]. The infection cycle then continues. However, when these microscopic spores can be aerosolized as sprays or powders, they can be released silently and escape detection. Even a small number of spores released in the air can infect massive numbers of people.  

In the United States, the Centers for Disease Control and Prevention (CDC) considers Anthrax as Category A – a Bioterrorism Agent. And indeed, the Bacillus Anthracis has been cultivated and used for bioterrorism from as early as 1915. 

A review of the GIDEON Bioterrorism note for Anthrax shows a long murky past of the pathogen being released by countries during the war, by terrorists to spread fear and destruction, or by accident. 

 

Image: Snippet of Bacillus Anthracis Bioterrorism Note from GIDEON database. Copyright © GIDEON Informatics, Inc.
Image: Snippet of Bacillus Anthracis Bioterrorism Note from GIDEON database. Copyright © GIDEON Informatics, Inc.

 

The 2001 U.S. Anthrax incident was more recent. A much larger Anthrax outbreak was an accidental 1979 Anthrax leak. Bacillus Anthracis spores were released from a secret Soviet military research center in Sverdlovsk, Russia. The story has all the intrigue and devastation that is characteristic of the Cold War. 60-70 people are estimated to have died from the accident, now termed the ‘Biological Chernobyl.’ The entire incident and related deaths were covered up and blamed on contaminated meat. It was only almost thirteen years later that a team of expert molecular biologists from Harvard University could investigate the spread of the spores on behalf of the CIA [5]. The team confirmed that aerosolized spores spread through the air and caused the outbreak, not meat. 

WATCH/LISTEN TO PODCAST: Dr. Berger discusses Anthrax infections and the associated bioterrorism history with ‘Outbreaks News’

Symptoms of Bacillus Anthracis Infections

Cutaneous Anthrax Infections

  • Itchy blisters or bumps
  • Painless skin sores that are black in the middle develop after the blisters or bumps 

Gastrointestinal Anthrax Infections

  • Fever and chills
  • Swelling of glands in the neck
  • Sore throat and trouble swallowing
  • Nausea and bloody vomit
  • Headaches
  • Diarrhea 
  • Stomach pain, and more

Inhalation Anthrax or Pulmonary Anthrax Infections

The most deadly but rare form of human anthrax infections. 

  • Fever and chills
  • Difficulty breathing
  • Cough
  • Dizziness 
  • Extreme fatigue
  • Sweats, and more.

 

This image depicts a man, whose left forearm exhibited a large cutaneous lesion, which had been diagnosed as a case of cutaneous anthrax, caused by the bacterium, Bacillus anthracis. Note the characteristic dark-brown to black-colored eschar that covered the lesion, from which the bacterium derives its name, being that the color resembles that of anthracite coal. The photographed had been captured by Georgian Field Epidemiology Training Program (FETP) resident, Archil Navdarashvili, while at Rustavi Hospital, in the country of Georgia, on August 25, 2012.
Image: This image depicts a man, whose left forearm exhibited a large cutaneous lesion, which had been diagnosed as a case of cutaneous anthrax, caused by the bacterium, Bacillus anthracis. Note the characteristic dark-brown to black-colored eschar that covered the lesion, from which the bacterium derives its name, being that the color resembles that of anthracite coal. The photograph was taken by Georgian Field Epidemiology Training Program (FETP) resident, Archil Navdarashvili, while at Rustavi Hospital, in the country of Georgia, on August 25, 2012.

 

Mitigating Bacillus Anthracis Infections

Cutaneous anthrax infections comprise the majority of anthrax infections worldwide. They are spread through contact with contaminated animals or animal products. The United States, the U.K., E.U., and many other countries worldwide have implemented better tests and protocols around the way animals are handled. With these processes in place, cutaneous anthrax infections have significantly decreased. 

However, it is extremely easy for anyone to carry an infectious disease endemic to one country and spread it to others. National public health agencies, frontline clinicians, infectious disease specialists, and microbiologists will have to work together to mitigate the effects of dangerous pathogens like the Bacillus Anthracis. Taking epidemiological data into account when diagnosing diseases in Point-of-Care settings can be a great first step towards containing emerging infections. 

 

Prefer your information in a video format? Here’s a recording of Dr. Berger discussing Anthrax on the ‘Outbreak News’ podcast:

 

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References 

[1] “China Reports First Human Case of Pulmonary Anthrax in 10 Years,” Caixinglobal.com. [Online]. Available: https://www.caixinglobal.com/2021-08-10/china-reports-first-human-case-of-pulmonary-anthrax-in-10-years-101753398.html. [Accessed: 26-Aug-2021].

[2] Global Times, “Shanxi Province reports 9 suspected anthrax cases, treatment underway,” Globaltimes.cn. [Online]. Available: https://www.globaltimes.cn/page/202108/1231472.shtml. [Accessed: 26-Aug-2021].

[3] Press Release, “Human anthrax case reported in Karabudakhkent region, Russia,” Outbreaknewstoday.com, 10-Aug-2021. [Online]. Available: http://outbreaknewstoday.com/human-anthrax-case-reported-in-karabudakhkent-region-russia-75939/. [Accessed: 26-Aug-2021].

[4] A. Chateau, S. Van der Verren, H. Remaut and A. Fioravanti, “The Bacillus anthracis Cell Envelope: Composition, Physiological Role, and Clinical Relevance”, Microorganisms, vol. 8, no. 12, p. 1864, 2020. Available: 10.3390/microorganisms8121864 [Accessed 26 August 2021].

[5] “Anthrax at Sverdlovsk, 1979”, Nsarchive2.gwu.edu, 2017. [Online]. Available: https://nsarchive2.gwu.edu/NSAEBB/NSAEBB61/#doc27. [Accessed: 26- Aug- 2021].

COVID-19 Vaccine: Do You Need It Even After Surviving COVID-19?

Brown t-shirt with 'I got my COVID vaccine' sticker on the pocket

written by Chandana Balasubramanian

“Should I get the COVID-19 vaccine even if I had COVID?” The answer is yes. Getting COVID-19 in the past is not a guarantee against reinfection.

An August 2021 study out of Kentucky, USA, studied hundreds of residents and found that unvaccinated survivors of COVID-19 had more than double the risk of getting reinfected with COVID-19 compared to the vaccinated group of people. Public health officials, medical professionals, and infectious disease experts worldwide continue to urge more people to get vaccinated as soon as possible. But some individuals who recovered from COVID-19 want to know why.

Wearing safety gear during on-ground combat will not prevent all adverse events. The gear is designed to prioritize and protect a soldier’s brain, heart, spine, and other vital organs from damage. The vaccines are meant to work the same way.

To those on the fence, the decision to get vaccinated or not requires more information. Queries from unvaccinated COVID-19 survivors include:

  • If you already had COVID-19, why are you not protected for life against the virus? After all, with a chickenpox infection, you get lifelong immunity.
  • If people who are vaccinated can still get infected with the Delta variant, why do we need the vaccine?
  • COVID-19 vaccines are currently approved for emergency use. Is this safe?
  • Which COVID-19 vaccine offers maximum protection against COVID-19 and variants like Delta?

Here are answers to these questions to help you choose.

Natural Immunity after COVID-19 varies widely from person to person. Vaccine immunity is more consistent.

Natural immunity from a COVID-19 infection is expected to last 90 days or more in most people. However, the strength of resistance built against COVID-19 varies widely from person to person. It is based on many factors, including viral load (the amount of virus in an infected person’s blood). People who had a light viral load the first time around may not be protected against reinfection. On the other hand, our immune response to the COVID-19 vaccine is more consistent. This is why you are encouraged to get vaccinated even if you had COVID-19.

Different pathogens trigger unique immune responses. The chickenpox virus (Varicella zoster) triggers the production of antibodies with lifelong memories that protect us against reinfection. COVID-19 is new, and so far, there is no data to suggest it offers immunity for life. With the COVID-19 mRNA vaccines, your body gets exposed to a harmless piece of the COVID-19 virus, the spike protein, which is just enough to train our immune system to learn how to fight this particular pathogen.

And for those previously infected with COVID-19, the vaccine can act as added protection, which is necessary to fight emerging variants.

New coronavirus delta variant covid. India mutation of SARS CoV 2, 2019 nCoV new version 2020 2021. Coronavirus new strain. 3D Illustration of viruses with microscope view of sliced virus

The Delta variant is a different beast; natural immunity needs all the help it can get.

The B.1.617.2 variant, or Delta, is significantly more contagious than the original COVID-19 virus from 2020 and all other existing variants. It is also more likely to cause severe disease and death by breaking through our natural immunity and even vaccine-related protections. This applies even if you recovered from COVID-19 in the past.

With the original COVID-19, symptoms took 7 to 14 days to appear. The Delta variant launches its attack on our body much faster. Symptoms could appear within two to three days – which means our immune system has less time to prepare. Additionally, people infected with the Delta variant carry 1000 times more virus than the original COVID-19. The vaccines can boost our natural immunity to strengthen our resistance against the new COVID-19 variants, including the insidious Delta.

It is important to note that the COVID-19 vaccines have proven effective at protecting against severe illness and death. It is still possible to get infected after being vaccinated. But if you are vaccinated, you will most likely experience milder symptoms without extreme damage to your lungs and other organs. In the United States, 97% of hospitalizations from Delta and 99% of associated deaths are due to unvaccinated individuals. These percentages are based on data from January to June and will be updated based on the impact of Delta.

Keep in mind that you are considered fully vaccinated two weeks after your second dose for two-dose vaccines or after one shot for a single-dose vaccine. Even after getting vaccinated, it is advisable to continue following recommended safety protocols.

According to Stephen Berger MD, an experienced doctor, war veteran, and infectious disease specialist, “Those that get vaccinated and then catch an infection, like the Delta variant, may have not yet formed antibodies.” Dr. Berger further stated, “People should still take the usual precautions and wear masks, sanitize their hands, and practice social distancing to help limit the spread of the virus.”

It’s like sending soldiers into battle. The process involves intense preparation and strategy beforehand. However, even the most experienced veteran returning to the call of duty requires armor, like helmets and bulletproof vests, and is trained to follow standard safety measures. The reason for this is because war brings a great deal of uncertainty and high mortality risk. Wearing safety gear during on-ground combat will not prevent all adverse events. The gear is designed to prioritize and protect a soldier’s brain, heart, spine, and other vital organs from damage. The vaccines are meant to work the same way.

The Delta variant may be dashing the world’s hope of reaching herd immunity since vaccinated individuals can spread the virus as much as the uninfected.

This insight makes it more urgent for each individual to get vaccinated and not count on herd immunity or immunity from prior infections to protect them. Professor Sir Andrew Pollard of the Oxford Vaccine Group recently informed that COVID is not like measles where if 95% of the population is vaccinated, the rest are protected. He stated, “…anyone still uninfected at some point will meet the virus.”

Meanwhile, the death knell from COVID-19 and the Delta variant continues to sound.

As of August 10th, 2021, more than 4.3 Million COVID-19-related deaths have been reported to the World Health Organization (WHO). The United States is in the lead with 600,000, followed by 563,000 in Brazil, and over 428,000 in India. In the United States, with only 50% of the population vaccinated, the daily case count now stands at 100,000 and is expected to grow. According to the CDC, the Delta variant is now the cause of 83% of all new cases in the U.S.

While the U.K. reported the highest single-day deaths from COVID-19 on August 11th, 2021 (their highest since March as a result of cases from July), hospitalizations, ICU admissions, and deaths were much lower in this wave than at the beginning of the year. Over 75% of adults in Britain have been fully vaccinated, and 89% have received at least one dose.

In the United States, while the COVID-19 vaccines are under evaluation for safety and efficacy, several have been approved for emergency use.

Portland, OR, USA - Mar 2, 2021: A woman browses the FDA website to learn more about COVID-19 vaccines. FDA has issued emergency use authorization for Janssen vaccine, the third COVID-19 vaccine.

 

Are vaccines approved under EUA or Emergency Use Authorization safe?

Several countries have granted preliminary approvals for vaccines in light of the devastation caused by COVID-19 and its variants. In the United States, vaccines by Pfizer-BioNTech, Moderna, and Johnson & Johnson (J&J) received EUA approval. Seeing that it is the first time vaccines are being granted EUAs, how effective are the vaccines?

In an ideal world, there would be long-term data and lots of time to analyze and decide whether to get vaccinated. In the future, COVID-19 vaccines may be like the chickenpox and flu vaccine, available for those who need it but not necessary. But right now, like medics on a battlefield, the biggest concern is to stop the bleeding. In the case of COVID-19 and its variants, it means minimizing hospitalizations due to severe illness and deaths. The three vaccines authorized under EUA in the U.S have proven effective against moderate to severe symptomatic disease.

While the EUA is a temporary fast-tracking of potentially life-saving drugs or therapy, it is not granted without reviewing detailed submissions from vaccine manufacturers containing proof of safety and data from clinical trials on more than thousands of willing participants. Another reason for the rapid FDA review and response is that the COVID-19 pandemic is the highest priority. So, resources to evaluate COVID-19 vaccines have been diverted accordingly.

In short, natural immunity will not last forever, the Delta variant is much more capable of breaking through natural immunity, and unvaccinated COVID-19 survivors have a higher likelihood of getting reinfected. If you choose to get vaccinated, here is a comparison of the reported COVID-19 vaccine efficacy against the Delta variant.

 

Comparison of COVID-19 vaccine protection against the Delta variant

1.    Moderna:

The Moderna vaccine is a two-dose vaccine, taken 28 days apart. It is an mRNA vaccine that makes the spike protein and teaches our body to create antibodies.

Effectiveness against Delta variant:

  • Two doses: 94-95% effective against the Delta variant [1] [2].
  • Single dose: 72% effective.

2.   Pfizer-BioNTech

The Pfizer-BioNTech vaccine is a two-dose vaccine taken 21 days apart. It is also an mRNA vaccine that makes the spike protein.

Effectiveness against Delta variant:

Reports vary between 79 – 95% so let us break them down:

  • A UK study demonstrates 88% overall effectiveness and 96% against hospitalization[3].
  • A Scotland study reported 79% effectiveness [4].
  • A study out of Canada showed 87% effectiveness [1].
  • A study out of Israel showed 90% effectiveness initially but more recently reported 41% effectiveness against symptomatic infections, but 91% effective against severe disease and 88% against hospitalization [5]. A report by the Ministry of Health, Israel, studying confirmed COVID-19 cases from January-July 2021, also showed that vaccinated individuals with pre-existing conditions are better protected against serious illness compared to non-vaccinated individuals without any risk factors [6].
  • A study from France reported 94% overall effectiveness with two doses [7].
  • A New York study stated 94-95% overall effectiveness [2].

3.   Johnson & Johnson – Janssen

The J&J Janssen vaccine is a viral vector vaccine, which uses inactivated and modified Adenovirus as a ‘Trojan horse’ to deliver the gene that encodes the SARS-CoV-2 spike protein. A well-known Bacillus Calmette Guerin (BCG) vaccine works the same way. The vaccine differs from other vaccines on the market in that it requires only one dose.

Effectiveness against Delta variant:

  • 66.9% efficacy in preventing moderate to severe disease. However, the study is small, and some experts now believe a booster may be required [2].

4.   AstraZeneca-Oxford (No EUA in the United States)

The AstraZeneca-Oxford vaccine, similar to the J&J Janssen vaccine, also works as a ‘Trojan Horse’ carrying valuable information to help train our immune system. The AstraZeneca vaccine requires two doses, taken 30 days apart.

Effectiveness against Delta variant:

  • The Public Health England study reported 79% overall effectiveness and 96% effective against severe disease[3].

 

Summary

All around the world, we are waging war against the COVID-19 virus and its variants. The Delta variant is the most dangerous and highly contagious of all emerging variants. Compared to the original COVID-19 and all its other variants, infection due to the Delta is most likely to result in death and severe illness.

Natural immunity gathered from a previous COVID-19 infection is not reliable protection from the Delta. Unvaccinated COVID-19 survivors have double the risk of being reinfected versus vaccinated COVID-19 survivors.

The bottom line is that regardless of the brand or type of vaccine you choose, experts recommend that you get fully vaccinated to protect yourself and your loved ones – even if you had COVID-19 in the past.

 

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References

[1] S. N. e. al., “Effectiveness of COVID-19 vaccines against variants of concern, Canada,” Pre-Print, 2021.
[2] T. T. e. al., “Comparison of Neutralizing Antibody Titers Elicited by mRNA and Adenoviral Vector Vaccine against SARS-CoV-2 Variants,” July 19th 2021. [Online]. Available: https://www.biorxiv.org/content/10.1101/2021.07.19.452771v1.full.pdf. [Accessed August 11th 2021].
[3] Public Health England, “GOV. U.K.,” June 14th 2021. [Online]. Available: https://www.gov.uk/government/news/vaccines-highly-effective-against-hospitalisation-from-delta-variant. [Accessed 11 August 2021].
[4] Sheikh, Aziz; McMenamin, Jim; Taylor, Bob; Robertson, Chris; Public Health Scotland and EAVE II Collaborators, “SARS-CoV-2 Delta VOC in Scotland: demographics, risk of hospital admission, and vaccine effectiveness,” The Lancet, pp. 2461-2462, June 14th 2021.
[5] Ministry of Health, Israel, “GOV. I.L.,” July 22nd 2021. [Online]. Available: https://www.gov.il/BlobFolder/reports/vaccine-efficacy-safety-follow-up-committee/he/files_publications_corona_two-dose-vaccination-data.pdf. [Accessed 11 August 2021].
[6] Ministry of Health, Israel, “Comparative Review of Confirmed Cases Data from January 2021 and July 2021,” https://www.gov.il/en/departments/news/25072021-04, 2021.
[7] D. Planas, D. Veyer, O. Schwartz and e. al., “Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization,” Nature, vol. 596, p. 276–280, 2021.

 

Nipah Virus Outbreaks: New Reasons Why the West Needs to Start Caring

Flying Pipistrelle bat (Pipistrellus pipistrellus) action shot of hunting animal on wooden attic of city church. This species is know for roosting and living in urban areas in Europe and Asia.
Image: Flying Pipistrelle bat (Pipistrellus pipistrellus) in the wooden attic of a city church. This species is known for roosting and living in urban areas in Europe and Asia.

 

written by Chandana Balasubramanian

Nipah virus (NiV) has been detected in several species of bats. While the Pteropus genus of bats has been the reservoir for NiV, new research from Gokhale et al. identified potential NiV infection in Rousettus leschenaultii and Pipistrellus pipistrellus bats in India [1].

Why is this significant?

In the past, the bat-borne Nipah virus has not raised much concern in the West –  since its discovery in the late nineties, outbreaks have been limited to Southeast Asia. However, NiV mutations, zoonotic spillovers, the effects of deforestation, and other factors signify a growing potential for NiV to spread. 

People think of these bat-borne viruses as exotic diseases that are far away. The COVID-19 pandemic illustrates, however, that local spillover of novel viruses can affect the whole world. 

– Stanford epidemiologist Stephen Luby, MD

Additionally, while NiV transmission was previously assumed to be annual or seasonal (primarily winter), a multi-disciplinary study based on six years of data indicates otherwise. Researchers from Stanford, Columbia, Johns Hopkins, and other global partners suggest that bat immunity levels drive NiV infections and that infected bats can shed the virus at any time of year [2].  This article was published in PNAS (Proceedings of the National Academy of Sciences of the United States) and edited by Anthony Fauci, Director of the National Institute of Allergy and Infectious Diseases.

This growing body of Nipah virus research is a bat signal urging the world to pay attention.

The World Health Organization (WHO) prioritized the Nipah virus on their list of epidemic threats that require urgent action. The US National Institutes of Allergy and Infectious Diseases categorizes Nipah at Category C:  “emerging pathogens that could be mass engineered for mass dissemination in the future.” Some governments consider the Nipah virus as a potential agent of bioterrorism and strictly regulate laboratory testing. Several other studies suggest that the NIV virus is a potential pandemic agent [3].

We must track Nipah like a parent that monitors an eight-year-old child in a playground. We do not have to divert all attention and resources urgently, but our eyes and ears need to “stay wide open” for potential issues.

Although NiV is a paramyxovirus – agents primarily responsible for acute respiratory diseases –  transmission from human to human is currently low. The R0 (the number of cases that result from an infected patient) is only 0.48. In comparison, the R0 for SARS-CoV-2 Delta Variant is 5-8, SARS-CoV-2 is 2.5-5.7, SARS-CoV is 2.4, and MERS is 1. Reported case mortality is high at 40 – 70% and is the reason why NiV has not caused mass transmission in a population:  many die before they transmit the disease. Another factor preventing larger outbreaks is that the virus has been detected in villages with a relatively low population density.

But changes are brewing, and we need to track the Nipah virus more closely than before. 

Reasons to Track Nipah Virus (NiV)

1. New Nipah virus mutations

With Nipah, there is no cause for panic just yet. Currently, only a small percentage of infected people transmit NiV. But super-spreaders can infect their loved ones, caregivers, healthcare workers, and others in their community. The incubation period is 5-to-14 days, but in a severe case, it has been reported to extend up to 45 days – sufficient time for an infected person to transmit the virus.

Nipah virus has been confined mainly to Southeast Asian countries with outbreaks in Bangladesh, India, the Philippines, and Malaysia. Still, as new strains continue to be detected, the threat level that NIV poses can potentially escalate. More research is needed in this field, but two distinct strains have been detected – Bangladeshi and Malaysian [2].

 

Nipah virus outbreaks map, 1998 - 2019
Image: Nipah virus global outbreaks map, 1998 – 2019. Copyright © GIDEON Informatics, Inc.

 

Consider another bat-borne disease: COVID-19. Since the start of the pandemic, SARS-CoV-2 has mutated quite rapidly. As you read this, variants such as ‘Delta’ (B.1.617.2) continue to wreak global havoc. WHO now categorizes these “mutants” as ‘Variants of Concern’ (VOC) and ‘Variants of Interest’ (VOI).

One concern is that the NIV receptor in humans is ephrin – found in all tissues. As such, infection by a more potent mutant could affect every organ in our body, including our blood and the central nervous system.

 

2. Potential Zoonotic Spillover: COVID-19 Pandemic Precedent?

As we saw with COVID-19, the spread from a bat to a pangolin and between humans happened extremely rapidly.

NiV was first discovered in pigs but is widely found in bats (Pteropus genus). There is also spillover to horses and other domestic animals. Nikolay et al. report that multiple Nipah spillover events from bats to humans occur in Bangladesh when humans consume raw fermented date palm sap contaminated by infected fruit bats [4]. Another reason for concern is that the Pteropus group of bats is found all over Asia and Australia. If more spillovers continue to occur, the world’s Nipah virus problem may increase quickly [2]. And as discovered in India (and always suspected by NiV experts), more bat species may be infected with NiV [1].

Stanford epidemiologist Stephen Luby MD stated about the Nipah virus, “People think of these bat-borne viruses as exotic diseases that are far away. The COVID-19 pandemic illustrates, however, that local spillover of novel viruses can affect the whole world.”

NiV and SARS-CoV-2 have similarities: both are bat-borne RNA viruses, demonstrate zoonotic spillovers, and cause acute respiratory distress – and without proper medical intervention, can be fatal. Differences include a slower rate of transmission for Nipah versus COVID-19 and its variants, for now. 

Nipah virus and COVID-19 comparison
Image: Comparison between Nipah virus and COVID-19. Copyright © GIDEON Informatics, Inc.

 

3. Nipah Virus can be transmitted continually

One of the most valuable insights from the Epstein et al. PNAS study was that bats do not transmit NiV annually or seasonally. Instead, there are multi-year cycles of transmission across bat species, which can increase the risk to humans.

Additionally, the study found that the Nipah virus in bats can recrudesce or reinfect the same bat. If an infected bat has high levels of immunity against NIV, it may not shed or transmit the virus. But when immunity levels are low, the same bat may start shedding the virus – even after years! If the immunity of a group of bats drops, an infected bat that immigrates to the flock could reinfect the group. Also, if one bat is persistently infected through recrudescence, NiV may be reintroduced into the bat colony [2].  

4. Ecological Changes Driving Closer Bat-Human Interactions

Generally, most animals prefer to stay away from humans. This is true unless their survival is linked to living closer to humans. In the case of Nipah, the Pteropus medius bat (the predominant host) travels short distances and likes to stay close to home. They pick their homes based on the availability of food in high human population density areas. In Bangladesh, they prefer to live close to humans because of more farmland and the greater availability of silver date palm trees. In Malaysia, fruit trees were planted close to piggeries, which, in turn, are within the range of human habitation. The United Nations projects that by 2050, 60% of the world’s population (4.9 billion people) will live in urban areas, increasing the risk of zoonotic spillovers. Most of this urbanization will occur in Asia and Africa.

Bat feces, called guano, is used as fertilizer in Thailand and Cambodia, and selling it is lucrative. Some people in these areas often encourage fruit bats to live close by for easier access to the droppings.

Deforestation is another strong influencer. Some research suggests that bats shed more virus under stress [6]. Bat populations undergo stressful environmental events such as human encroachment, deforestation, and fires that cause them to flee their natural habitats, searching for new ones. Many of them choose to “cut out the middleman” and roost directly on fruit trees, often planted close to humans and other domesticated or farm animals. 

Two men cutting a tree
Image: Deforestation. Photo by Souro Souvik on Unsplash

 

Additionally, bats, including Pteropus medius, are gregarious and social animals. Living in a large roost also offers them greater protection from other predators. Pteropus Medius bats prefer to create large roosts in tall trees. But with deforestation on the rise, these bats have been forced to form smaller populations in other locations [7].

Image: Nipah virus infection summary of disease from GIDEON Informatics (Global Infectious Diseases and Epidemiology Network) database.
Image: Nipah virus infection summary. Copyright © GIDEON Informatics, Inc.

 

Nipah infections are characterized by encephalitis and acute respiratory distress, which are incredibly difficult to treat [5]. The mortality rate is at 40-70%. Since it is found in rural areas with limited lab testing resources and awareness, early detection is often not possible. There are no licensed treatments for Nipah virus infection though some monoclonal antibody therapies are being evaluated. Additionally, there is no vaccine against this virus. According to GAVI, the global vaccine alliance, phase 1 clinical trials are underway.

With COVID-19 being a global public health crisis, investments in vaccine R&D and production have been high from the get-go. But the same mRNA vaccine technology may also be useful in preventing NiV infections.

Conclusion

Nipah virus has been around for 20 years and persists without a vaccine or licensed drug treatment. Though transmission rates are low, mortality rates are high.

The virus has much in common with SARS-COV-2. In particular, both are bat-borne, RNA-based viruses that have spilled over to other animals and humans. The virus of COVID-19, mutating much more often, has spread to every corner of our globe in a full-blown pandemic.

Variant strains of the Nipah virus have been detected. New research also identified more species of bats infected with the NiV virus. Preventing the next pandemic involves equipping researchers and clinicians on the frontlines of emerging disease prevention with the right epidemiological, diagnostic, therapeutic, and preventive tools, right off the bat. 

 

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References

[1] M. D. Gokhale, M. Sreelekshmy, A. B. Sudeep, A. Shete, R. Jain, P. D. Yadav, B. Mathapati and D. T. Mourya, “Detection of possible Nipah virus infection in Rousettus leschenaultii and Pipistrellus Pipistrellus bats in Maharashtra, India,” Journal of Infection and Public Health, vol. 14, no. 8, pp. 1010-1012, 2021.
[2] J. H. Epstein, S. J. Anthony, A. Islam, A. M. Kilpatrick, S. Ali Khan, M. D. Balkey, N. Ross, I. Smith, C. Zambrana-Torrelio, Y. Tao, A. Islam, P. Lan Quan, K. J. Olival, M. S. U. Khan, E. S. Gurley, M. J. Hossein, H. E. Field, M. D. Fielder, T. Briese, M. Rahman, C. C. Broder, G. Crameri, L.-F. Wang, S. P. Luby, I. W. Lipkin and P. Daszak, “Nipah virus dynamics in bats and implications for spillover to humans,” PNAS (Proceedings of the National Academy of Sciences of the United States of America, vol. 117, no. 46, pp. 29190-29201, 2020.
[3] P. Devnath and H. M. A. A. Masud, “Nipah virus: a potential pandemic agent in the context of the current severe acute respiratory syndrome coronavirus 2 pandemic,” New Microbes and New Infections, vol. 41, 2021.
[4] B. Nikolay, H. Salje, J. M. Hossain, A. M. Dawlat Khan, H. M. S. Sazzad, M. Rahman, P. Daszak, U. Ströher, J. R. C. Pulliam, A. M. Kilpatrick, S. T. Nichol, J. D. Klena, S. Sultana, S. Afroj, S. P. Luby, S. Cauchemez and E. S. Gurley, “Transmission of Nipah Virus – 14 Years of Investigations in Bangladesh.,” New England Journal of Medicine, vol. 380, no. 19, pp. 1804-1814, 2019.
[5] E. S. Gurley, C. F. Spiropoulou and E. d. Wit, “Twenty years of nipah virus research: Where do we go from here?” J. Infect. Dis., vol. 221, No Supplement_4, p. S359–S362, 2020.
[6] C. M. Davy, M. E. Donaldson, S. Subudhi, N. Rapin, L. Warnecke, J. M. Turner, T. K. Bollinger, C. J. Kyle, N. A. S.-Y. Dorville, E. L. Kunkel, K. J. O. Norquay, Y. A. Dzal, C. K. R. Willis and V. Misra, “White-nose syndrome is associated with increased replication of a naturally persisting coronaviruses in bats,” Scientific Reports, vol. 8, no. 15508, 2018.
[7] C. D. McKee, A. Islam, S. P. Luby, H. Salje, P. J. Hudson, R. K. Plowright and E. S. Gurley, “The ecology of Nipah virus in Bangladesh: a nexus of land use change and opportunistic feeding behavior in bats,” Viruses, vol. 13, no. 169, 2021.

 

 

Less Prep, More Insights: GIDEON R for Epidemiology-Related Research

We are excited to introduce the GIDEON R Package, released this month as a beta test for our researchers worldwide. GIDEON R is an efficient plug-and-play statistical tool for all researchers to clean, analyze, and visualize their epidemiological data from the GIDEON database. There is no need to program your own REST API queries. 

In the past 3 years, 200+ research papers used GIDEON data

EXCLUSIVE SNEAK PEEK FOR EXISTING GIDEON CUSTOMERS

  • All existing GIDEON customers get early access to experience and test the GIDEON R Beta package. Click here to download the package.
  • Let us know what you think! Email us at kristina@gideononline.com and tell us what you liked and what could be improved.
  • Your comments help us refine and launch the best version of GIDEON R for your research needs.
GIDEON R package in use
Image: GIDEON R package in use

 

Over 200 scientific studies that leveraged GIDEON’s (Global Infectious Diseases and Epidemiology Network) database were published in just the past three years. This number is rapidly growing as many researchers turn to the extensive infectious disease database for epidemiological insights and cross-discipline studies. 

The GIDEON database is a valuable web-based reference of infectious diseases and their global occurrences since the 1900s. As of 2020, researchers also get to customize and build their statistical tools to analyze data using the GIDEON API or Application Programming Interface (API). 

While GIDEON’s massive global database of infectious diseases and the GIDEON API are potent tools, GIDEON R allows you to boost your analytics to the next level. 

Why use GIDEON R?

R, the free, open-source programming language, has transformed how researchers prep, clean, and wrangle large databases to get good information. With minimal coding required, researchers can clean and set up their data faster and conduct reproducible steps during data analysis. 

R is quickly gaining in popularity with researchers. R programming is a part of the standard data analytics curriculum in universities like Harvard and the Imperial College in London. It is fast becoming a mainstay in Public Health and epidemiological research studies and reports. In the UK, the O Health foundation, an independent charity, developed an NHS-R community to help leverage the power of R for the NHS (National Health System). Teams of experts trained NHS analysts to use and embed R into the NHS to help improve the delivery of care.  

Using the GIDEON R package brings you more efficiency to:

  • Investigate 25,000+ ongoing and historical infectious disease outbreaks,
  • Produce granular outbreak maps for chosen diseases in a given year range
  • Study the emergence of zoonotic diseases in a particular country,   
  • Evaluate epidemiological situations around the globe, 
  • Retrieve a wealth of information on 360+ infectious diseases, 2,000+ pathogens, and 30,000+ trade names of drugs and vaccines.

The GIDEON R package brings all the convenience and efficiency of the free, open-source programming language R to the world of epidemiological research. 

Benefits of using GIDEON R include…

  • Simplicity: 

There is no need to learn how to work with a REST API client to parse the GIDEON database. With GIDEON R, you can hit the ground running and start crunching your data. 

Working with a GIDEON REST API offers you greater and complete control over how your program manipulates data. However, it requires users to possess programming skills and may also mean an investment in rigorous manual and automatic testing to ensure it functions well under pressure. Your team will need to spend considerable time testing, sequencing API calls correctly, validating parameters, and fixing any other issues before beginning the analysis. GIDEON R gives researchers familiar with R the ability to skip this part of the process and get straight to the analytics.  

  • Reproducibility: 

GIDEON R allows you to create scripts for your entire data analysis process and run a simulation. This way, even if you make a mild edit to the data, the whole process can be run again with the reassurance of reproducibility. As a researcher, you can then focus on developing and analyzing different runs without worrying about the analytical method changing. 

  • Flexibility

Epidemiological research is complex and challenging. No two studies will ever be precisely the same. R offers a considerable toolkit of statistical modeling tools that epidemiologists require, including logistic and Poisson regression and Cox proportional hazard models. 

  • Better Visualization

With R, data comes to life. Using R for data visualization is like the famous scene in the classic movie ‘The Wizard of Oz’ when Dorothy steps out of her dull black and white house and into the dazzling technicolor land of Oz. 

R can create any type of graph or charts – fast ones for analysis and even publication-ready charts with minimum code. R offers in-built functions and libraries to generate basic maps like bar charts, histograms, and scatter plots. It can also create advanced visualization tools like heat and mosaic maps, 3D graphs, or correlograms in vivid technicolor for your exploratory data analysis, presentations, and publications.

  • Compatibility

R runs on everything. R’s code is platform-independent – which means it does not matter if you use Windows, Mac, or any other system. So, with GIDEON R, you can be sure that your program is compatible with any type of platform you or your team use. This is a significant benefit when working with teams located in different regions and across the globe. 

GIDEON R optimizes how researchers use the GIDEON API to mine the GIDEON infectious disease database for epidemiological research. 

 

Want to be one of the first to try the new GIDEON R package?

  • If you are an existing GIDEON customer, click here to sign up for our beta test. Please give us your feedback at kristina@gideononline.com.
  • If you are not an existing GIDEON customer but would like to be, sign up for a free demo to get started.

 

GIDEON API

The GIDEON API allows medical professionals and researchers pressed for time and resources access to global data on hundreds of diseases, drugs, and bacteria – since 1348 AD. 

With the GIDEON API, you get a direct feed of infectious disease data from around the world at your fingertips. The GIDEON API is based on RESTful principles, and data is refreshed and updated every day, sometimes even multiple times a day. 

The best part? All institutional subscribers to GIDEON get access to the GIDEON API free of charge. 

 

Published articles that used GIDEON

Epidemic infectious disease outbreak with person analyzing virus strain and worldwide situation. SARS-CoV-2 pathogen causing coronavirus covid-19 pandemic disrupting social and economic life

According to Professor Rodolphe Desbordes, Professor of Economics at SKEMA Business School, France, and widely published in International Economics and Economic Development: 

GIDEON was the perfect database for the epidemiological project I had in mind <…> the information provided on each disease was crucial to a better understanding of disease-specific characteristics.

 

GIDEON has a rich history of partnering with researchers and scientists worldwide by offering a wide variety of resources on infectious diseases. You can find data going back to 1348 AD, track outbreaks on an interactive map, identify over 2000+ pathogens, diagnose and compare any number of infectious diseases, drugs, and microbes. 

The GIDEON database contains 23,600 country-specific notes with 3+ million words of text that outline the status of specific infections within each country. Also featured are over 250,000 linked references, 3,000 images, 34,000 graphs, and numerous interactive maps. 

There are more than 200 studies published in just the past three years that use GIDEON’s database to generate meaningful insights. Here are a few of the recent articles published that used GIDEON for their research: 

  • June 2021, Dengue: Alisa Aliaga-Samanez et al. from Spain published the first high-resolution analysis of biogeographic changes in dengue transmission risk. The study informs about the Dengue virus (DENV) making a home in previously low-risk areas and urges the global public health community to implement preventive measures [1]. 

 

  • June 2021, Foodborne Parasitic Diseases: F. Chavez-Ruvalcaba et al. published their review of foodborne parasitic diseases in the neotropics. Since more than one-fifth of the world’s population is infected by one or more intestinal parasites, the authors review the most common ones affecting countries in Central and South America [2]. 

 

  • June 2021, Lyme Borreliosis in Poland: Brzozowska et al. published their study about the tick-borne Lyme Borreliosis in Poland. They found the incidence to be equally significant in urban and rural communities and stressed the importance of widespread awareness and education. The study used GIDEON-generated data to compare Lyme Borreliosis prevalence across the globe [3].  

 

  • May 2021, Control of Intestinal Nematodes in African Green Monkeys (AGMs): A veterinary study by Katalina Cruz et al. tackled the efficacy of antiparasitic treatment and husbandry methods to control nematode infections in AGMs. The authors referred to insights from the GIDEON database to highlight that because AGMs regularly come in contact with humans on the island, they may play a role in the zoonotic parasitic infections commonly found on St. Kitts [4]. 

 

  • May 2021, Emerging Antibiotic-Resistant Pathogens in Iran: As part of their study, Rahder et al. analyzed the reported prevalence of actinomycetes infections worldwide using published global prevalence data sourced from the GIDEON database. They identify infections in Iran affecting immunocompromised and other vulnerable patients and recommend continuous monitoring to better prevent infection and improve therapeutic methods to treat the infections [5]. 

 

  • March 2021, Brucellosis: Battikh et al. from Tunisia used the GIDEON database to analyze the rise in Brucellosis cases in their hospital. They found that osteoarticular involvement was the most common complication of brucellosis in their patient pool. The researchers recommended better animal control practices through vaccinations, occupational and personal hygiene, farm sanitation, and more to lower the number of cases [6]. 

 

  • March 2021, Global Empirical Assessment of Spatial Dynamics of Major Disease Outbreaks: Professor Rodolphe Desbordes presented the spatio-temporal dependence and mortality consequences of the top 15 disease outbreaks in developed or developing countries over ten years. In the article, he states that his team mainly relied on the “under-exploited GIDEON database that provides a worldwide coverage of all infectious diseases [7].”

    In an interview, Professor Desbordes talked about why having access to data added to his study. He mentioned, “As an applied economist, I value excellent data on a novel and interesting issue more than anything else. The GIDEON database allowed me to publish in an excellent journal and, most importantly, carefully model the spatial diffusion of infectious diseases in a globalized world.”

 

  • March 2021, Ecological Conditions That Increase Vector-Borne and Zoonotic Diseases Outbreaks: Morand and Lajaunie published their findings on how global forest cover changes and oil palm expansions are associated with increased outbreaks of vector-borne and zoonotic disease outbreaks from 1990 – 2016. The authors state, “Here, we examine the global trends between changes in forest cover in recent decades and epidemics of human infectious diseases, using the GIDEON global database, which is the best available dataset on infectious diseases that has already been used in several studies [8].”

 

Want to be an early user and test GIDEON R?

  • All existing GIDEON customers get free access to experience and test the GIDEON R Beta package. Click here to start.
  • Let us know what you think! Email us at kristina@gideononline.com with what you liked and what could be improved.
  • Not an existing GIDEON customer? Don’t worry. We’ve got you covered. Sign up here for a free demo to get started.

Conclusion

GIDEON is one of the most well-known and comprehensive global databases for infectious diseases. Data is refreshed daily, and the GIDEON API allows medical professionals and researchers access to a continuous stream of data. 

The GIDEON R package allows researchers to retrieve, clean, analyze, and visualize infectious disease data in real-time from the GIDEON database without the need to get familiar with API clients and learn to program your own API queries. This improves the efficiency and reproducibility of research methods and results and lowers the time and costs required to learn how to work with REST APIs.

 

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References

[1]  A. A.-S. e. al., “Worldwide dynamic biogeography of zoonotic and anthroponotic dengue,” PLoS Negl. Trop. Dis., vol. 15, no. 6, p. e0009496, 2021. 
[2]  F. Chávez-Ruvalcaba, M. I. Chávez-Ruvalcaba, M. K. Santibañez, J. L. Muñoz-Carrillo, C. A. León and R. R. Martínez, “Foodborne Parasitic Diseases in the Neotropics – a review,” Helminthologia, vol. 58, no. 2, pp. 119-133, 2021. 
[3]  M. Brzozowska, A. Wierzba, A. Śliwczyński, M. Myśliwiec, K. Kozłowski and W. Wierzba, “The problem of Lyme borreliosis infections in urban and rural residents in Poland, based on National Health Fund data,” Annals of Agricultural and Environmental Medicine, vol. 28, no. 2, p. 277–282, 2021. 
[4]  K. Cruz, T. M. Corey, M. Vandenplas, M. Trelis, A. Osuna and P. J. Kelly, “Case report: Control of intestinal nematodes in captiveChlorocebus sabaeus,” Onderstepoort Journal of Veterinary Research, vol. 88, no. 1, pp. 2219-0635, 2021. 
[5]  H. A. Rahdar, S. Mahmoudi, A. Bahador, F. Ghiasvand, H. Sadeghpour and M. M. Feizabadi, “Molecular identification and antibiotic resistance pattern of actinomycetes isolates among immunocompromised patients in Iran, emerging of new infections,” Scientific Reports, vol. 11, 2021. 
[6]  H. Battikh, A. Berriche, R. Zayoud, L. Ammari, R. Abdelmalek, B. Kilani, H. Tiouiri Ben Aissa and M. Zribi, “Clinical and laboratory features of brucellosis in a university hospital in Tunisia,” Infectious Diseases Now, 2021. 
[7]  R. Desbordes, “Spatial dynamics of major infectious diseases outbreaks: A global empirical assessment,” Journal of Mathematical Economics, vol. 93, 2021. 
[8]  S. Morand and C. Lajaunie, “Outbreaks of Vector-Borne and Zoonotic Diseases Are Associated With Changes in Forest Cover and Oil Palm Expansion at Global Scale,” Front. Vet. Sci., vol. 8, p. 230, 2021. 
[9]  R. e. al., “Data proliferation, reconciliation, and synthesis in viral ecology,” bioRxiv, 2021. 

New Dengue Study Identifies New High-Risk Countries

Pathogen of the month: Dengue virus

 

A man using a sprinkler ULV type for kill mosquito carrier of Zika virus and dengue fever it outbreak in school at the rainy season.
Image: Sprinkling to kill Aedes aegypti, a vector of Dengue, during the rainy season.

 

written by Chandana Balasubramanian

Halfway through every Hollywood disaster movie, when all hell breaks loose, a few rogue scientists are brought in. This handful of experts would have predicted the disease outbreak or catastrophe years, or sometimes decades, before. But their advice would have fallen on deaf ears – until it was almost too late.

Meanwhile, in real life, a large and vocal group of researchers and public health organizations are sounding the alarm about Dengue as a pandemic-level threat in the near future.

The relatively good news is that Dengue, a vector-borne illness, is not transmissible between humans. So, we can prevent a full-blown Dengue pandemic if the global community of public health officials:

But why is Dengue such a colossal threat? Why is prevention important?

 

Dengue cases on the rise

Currently, Dengue cases are estimated to be anywhere from 5 – 100 million. This wide range is because many cases stay unreported, or the symptoms of Dengue are confused for other diseases. But the number of Dengue cases is expected to boom in the next few decades, with 60% growth by 2080 [1].

The latest study on the spread of Dengue is by Aliaga-Samanez et al. from Spain [2]. The study is the first high-resolution analysis of how the risk of Dengue transmission has been changing geographically since the late 20th century. The study uses robust databases like the World Health Organization (WHO) [1], and the Global Infectious Disease and Epidemiology Online Network (GIDEON) [3] to track and map global Dengue cases since the 1900s.

All Dengue experts agree that the number of Dengue cases is rising fast and spreading wide across the globe. WHO estimates that about half the world’s population is now at risk [4]. Aliaga-Samanez et al. identified that the Dengue virus (DENV) has been making a home in previously low-risk areas, potentially due to global warming and deforestation. The authors also report that while the Aedes mosquito is responsible for Dengue transmission, DENV can be spread by primates and could adapt to be transmissible by other vectors.

Tracking the geographical spread of the Dengue virus by different vectors is complex. According to the primary researcher Alisa Samanez, using the GIDEON database – “one of the most complete data sources worldwide on zoonoses” – to build their own database was a significant factor to track a zoonotic disease like Dengue.

 

Reported Dengue cases in different regions, 1980 – 2020

Graph illustrating Dengue cases in different regions, 1980 - 2020
Image: Graph illustrating Dengue cases in different regions, 1980 – 2020. Copyright © GIDEON Informatics, Inc.

 

Dengue mosquitoes spread their wings worldwide

While Dengue cases are primarily found in the tropical regions of Asia, Africa, and the Americas, this is rapidly changing. The study from Spain determined that other regions now at risk are South-East China, Papua New Guinea, North Australia, South USA, parts of Colombia, Venezuela, Madagascar, and even Japan and South and Central Europe. The study predicts that Dengue could spread to Argentina and South-West Asia, from Pakistan and the Arabian Peninsula.

Ideally, public health officials in these regions will begin training their healthcare professionals to diagnose and treat Dengue early and raise awareness among their populations.  

For example, initially, Egypt’s Ministry of Health dismissed reports of Dengue fever in certain regions. But eventually, they reviewed published reports of Dengue outbreaks in studies that used GIDEON’s clinical tools. This prompted them to develop a training program for their health workers for the early detection and treatment of Dengue [5].

Two significant factors accelerating the spread of Dengue worldwide are the 2.9 trillion U.S dollar global travel and tourism industry and climate change.

Many studies indicate that international travelers are at considerable risk for Dengue spread. Ratnam et al. from Australia concluded that Dengue infections in international travelers occur frequently and may be associated with substantial morbidity [6]. 

What is worrisome is that while Dengue is not directly contagious between humans, it is transmittable from an infected human to an infection-free Aedes mosquito. So, if a Dengue-infected individual travels to another country during the viremic or infection-spreading period, a native Aedes mosquito may bite the individual and become infected [7]. This newly infected mosquito can infect other individuals.

Additionally, climate change is a contributor because rising temperatures in previously colder environments are fertile grounds for mosquitoes to thrive. Higher temperatures also shorten the cycle of a mosquito picking up a Dengue infection and transmitting it.

 

Captured in La Paz, Honduras, this August 2019 photograph, depicted Dr. Liliana Sanchez-Gonzales on the left, an Epidemiologist with the Centers for Disease Control and Prevention’s (CDC) Dengue Branch, along with an unidentified Honduran physician, as they were examining the chest x-ray of a patient, who was on the verge of developing severe dengue. The x-ray revealed the presence of fluid in her lungs, possibly due to plasma leakage, as she was going into dengue-related shock.
Image: Captured in La Paz, Honduras, this August 2019 photograph, depicted Dr. Liliana Sanchez-Gonzales on the left, an Epidemiologist with the Centers for Disease Control and Prevention’s (CDC) Dengue Branch, along with an unidentified Honduran physician, as they were examining the chest x-ray of a patient, who was on the verge of developing severe dengue. The x-ray revealed the presence of fluid in her lungs, possibly due to plasma leakage, as she was going into dengue-related shock.

 

Why is Dengue dangerous?

According to WHO, severe Dengue is a leading cause of serious illness, hospitalization, and death among children and adults in some Asian and Latin American countries [4]. Severe Dengue involves severe bleeding, liver, heart, and other organ impairment, and plasma leakage.

Many Dengue infections are mild with flu-like symptoms, but a lack of awareness and early detection could lead to severe Dengue. And since the incubation period varies from four to ten days, it may be overlooked or misdiagnosed until it becomes severe. Additionally, because there are four different types of the Dengue virus, individuals once affected by Dengue can be re-infected up to four times.

The Dengue vaccine is only available in certain countries and, as per WHO, is restricted to those aged 9 to 45 and individuals previously infected by DENV. Hopefully, we get a better alternative. But until then, we need to raise awareness about early detection and treatment on the frontlines and track outbreaks closely.

 

Conclusion

If we have learned anything from the COVID-19 pandemic, it is this: the best disaster control is early detection and prevention. According to Aliaga-Samanez et al., Dengue is poised to be the next pandemic. Only through global collaboration, rigorous tracking, and preventive public health programs can we banish health catastrophes like a Dengue pandemic to the world of fiction – away from our collective reality.

 

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References

[1] World Health Organization, “Global strategy for Dengue prevention and control, 2012-2020,” World Health Organization, Genève, Switzerland, 2012.
[2] A. A.-S. e. al., “Worldwide dynamic biogeography of zoonotic and anthroponotic Dengue,” PLoS Negl. Trop. Dis., vol. 15, no. 6, p. e0009496, 2021.
[3] B. S, “Dengue: Global Status,” GIDEON Informatics, Inc., Los Angeles, California, USA, 2015.
[4] W. W. H. Organization, “Dengue and Severe Dengue Fact Sheet,” World Health Organization, 19 May 2021. [Online]. Available: https://www.who.int/news-room/fact-sheets/detail/Dengue-and-severe-Dengue. [Accessed 04 07 2021].
[5] Department of Tropical Medicine, Ain Shams University, Cairo, Egypt, “Dengue fever, Correspondence to Nadia A Abdelkader, MD,” Egypt J Intern Med, vol. 30, pp. 47-48, 2018.
[6] F. Irani Ratnam, “Dengue Fever and International Travel,” Journal of Travel Medicine, vol. 20, no. 6, p. 384–393, 2013.
[7] J. P. Messina, “The current and future global distribution and population at risk of Dengue,” Nature Microbiology, vol. 4, p. 1508–1515, 2019.

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