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Archive for the ‘Outbreaks’ Category

Is COVID-19 the new plague?

written by Dr. Stephen A. Berger

Illustration of plague outbreaksA frightening pandemic arises from animals in Asia and spreads westward, killing thousands in Italy, France, Spain, and many other countries. The more severe infections are characterized by cough and fever, leading to progressive pneumonia. There is no specific treatment available, and entire cultures live in fear and uncertainty.  

And so, during 541-542 C.E. Yersinia pestis the bacterium that causes bubonic plague, spread out from China into the Byzantine Empire. Few were spared, and an estimated 25 to 100 million Europeans went on to die during repeated waves of infection that struck the region over the next 200 years. As many as 5,000 plague deaths per day were recorded in the city of Constantinople. This “Justinian Plague” is named for the Emperor Justinian, who managed to survive an attack of the illness (less-fortunate victims included Pope Pelagius II and Wighard, Archbishop of Canterbury) 

In recent years, much is written regarding the risk of the spread of infectious diseases related to global warming. In fact, there is some evidence that the Justinian plague was the product of global cooling. Five years before the onset of the pandemic, emissions from a volcano may have significantly lowered atmospheric temperature, resulting in the migration of rodents deprived of food. Fleas, which spread plague from rodents to humans, are unable to efficiently digest their blood meals at low temperatures, causing them to vomit as they attempt to feed again – injecting contaminated material into their hosts. 

The Justinian plague largely spared the Arabian Peninsula, thus nourishing the rise of Islam and Arab armies which easily went on to conquer large areas of a devastated Europe. 

From 1347 to 1351, a second plague pandemic – The Black Death – killed 75 to 200 million humans – an estimated ten-to-sixty percent of the European population. Once again, the disease originated in Asia, entering through Sicily on Genoese galleys, and reaching Venice in 1348. The irony of a pestilence from China spreading through northern Italy is obvious in light of current events. Just as the Justinian Plague claimed the life of Bishop Wighard, the Black Death killed two Archbishops of Canterbury in a single year – Thomas Bradwardine and John de Ufford.   

Just as the Justinian Plague altered the future of Europe, the Black Death may well have paved a path into the Renaissance.  

As of March 2020, there is little similarity between COVID-19 and Bubonic plague; but the current massive disruption of society will surely have consequences for human civilization in years to come.

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Read more on the global status of Major Coronaviruses

Read more on the global status of Plague

Ebola, forgotten but not gone

written by Dr. Stephen A. Berger, Dr. Yaakov Dickstein, and Edward Borton

The recent WHO decision to declare the novel coronavirus outbreak a Public Health Emergency of International Concern (PHEIC), while both appropriate and hardly surprising, offers the opportunity to reflect on the previous PHEIC which was declared, namely the Ebola epidemic in Kivu region, Democratic Republic of the Congo (DRC). And you should really say the ongoing Ebola epidemic, as during the time since the declaration in July 2019 through to the present day (March 2020), a total of 3,453 cases have been reported [1].

The nCoV-2019 outbreak is still ballooning; as of today, over 400,000 confirmed cases worldwide with no signs of slowing down [2]. To date, there have been 19,786 fatalities, a mortality rate which is notably higher than the rate observed in the 2018-9 influenza pandemic (>2.5%) and significantly higher than AH1N1 (~0.05%) [3,4]. As you might have hoped, the response has been incredibly rapid, faster than ever seen before with a new human pathogen. Within weeks of identifying an outbreak of respiratory illness, the virus has been identified, sequenced and cultured; rapid tests are available for diagnosis (albeit with continuing broadening and narrowing); at least two randomized controlled trials (RCTs) are being performed to analyze the effect of antiviral medications, one with a new drug; and the largest infection control effort in history is underway, including the quarantine of more than 50 million inhabitants in Hubei province, China [5]. Internationally, airlines have ceased operating to China; large-scale surveillance of suspected patients and their contacts is being performed around the clock, and naturally, the media response has been extensive. It would prove more difficult to find someone who didn’t know of the new coronavirus than someone unaware.

The history of Ebola is different, both in impact and response. Ebola is vicious; out of 3,453 cases confirmed since the beginning of the current outbreak, 2264 or 66% have died, similar to ratios from previous outbreaks and among the highest case fatality rates of any human pathogen [1]. First isolated in 1976 following separate outbreaks in Sudan and what was then Zaire, there have been numerous outbreaks of Ebola since, both small and large, however scientific and media attention was limited for the first 20 years. An average of just 9 yearly publications related to the virus was published between 1977-1994 and it was only in 1995, when a major outbreak occurred in DRC, that interest began to be generated [6]. Coincidentally, the movie ‘Outbreak’, released just two months before the first cases in the DRC, also served to increase public awareness of the disease. It was the 2014-6 epidemic, however, which displayed the epidemic potential of the disease, with nearly 30000 suspected cases and more than 11000 fatalities [7]. The declaration of a PHEIC and a global response followed, including the use of experimental antiviral treatment and vaccination. Nevertheless, it took two years before the epidemic terminated.

It may well be an inconvenient truth that the responsiveness to any outbreak will be based on the impact on Western society, chiefly the economy, rather than the severity of the illness and endangerment to human life and well-being. Notwithstanding the vast amount of funds the global economy generates for medical research and treatment production, a more consistent global approach to tackling both the outbreaks themselves and managing awareness and attention would give less developed countries a better platform to address the events in a timely manner, minimizing the risk of extreme outcomes.

Thankfully the current outbreak has been less explosive than that of 2014-6, which could explain, if not forgive, the correspondingly tepid response; while organizations such as Médecins Sans Frontières (MSF, Doctors Without Borders) have been on the front lines from the beginning, it took the WHO four reviews of its original negative decision before they announced a PHEIC. Unfortunately, the situation has been complicated considerably by an ongoing conflict, which has escalated to actively target healthcare workers, including 386 attacks with 77 injured and 7 dead in 2019 [8]. Nevertheless, work has continued and has borne fruit and new cases of Ebola have declined significantly during the current outbreak since the end of September 2019, with only one newly-confirmed case this past week and hopefully, an end is close [1].

Outside of any political or economic reason, it is perhaps human nature to be attracted and fascinated in that which is new and shrouded in mystery and misinformation, and it is seemingly appropriate that the word “novel” (from Latin Novus, “new” or “fresh”) has been incorporated into the name of the virus which now makes the headlines. All the same, the fact that a public health emergency is currently of less international import or concern does not make it any less important or pressing, especially to the locals and health care workers fighting the illness. Given the WHO saw fit to label it as such an emergency, it should also see fit to continue rendering assistance proportionate to that description until the emergency is completely over and the region free from further risk; otherwise why have such labels at all?

Read more on the global status of Ebola

  1. Accessed 3rd March 2020
  2. Accessed 11th March.2020
  3. Taubenberger JK, Morens DM. 1918 Influenza: the mother of all pandemics. Emerg Infect Dis 2006 Jan;12(1):15-22
  4. Nishiura H. The virulence of pandemic influenza A (H1N1) 2019: an epidemiological perspective on the case-fatality ratio. Expert Rev Respir Med. 2010 Jun;(4)3:329-38
  5. See ProMED string for Novel coronavirus at
  6. Pubmed search for “Ebola”, performed 6.2.2020.
  7. WHO Ebola virus disease fact sheet. Accessed 6.2.2020.
  8. Accessed 6.2.2020.

Japanese Encephalitis in India

Outbreaks in Japanese encephalitis (JE) / Acute encephalitis syndrome (AES) have been reported from Assam and Uttar Pradesh in recent weeks.  Since 2008, official reports from India do distinguish between these two entities.  The following chart [1] indicates that although India has experienced increasing rates for both JE and AES on a national level,  incidence has not increased in these two states. [2,3]


1. Gideon e-Gideon multi-graph tool,
2. Berger S. Infectious Diseases of India, 2019. 620 pages , 109 graphs , 6,807 references. Gideon e-books,
3. Berger S. Japanese Encephalitis: Global Status, 2019. 100 pages , 66 graphs , 1,208 references.  Gideon e-books,

Histoplasmosis in Travelers

In 2019, several Canadian tourists acquired histoplasmosis while exploring caves in Cuba.  The Gideon database maintains an ongoing record of all cross-border Infectious Diseases events, including importation of animals and foods associated with zoonotic disease. [1-3]

As of 2019, 76 episodes of histoplasmosis had been associated with travel, involving at least 574 individual cases (8 fatal).  18 of these events were related to cave exposure, including two involving caves in Cuba.  Four publications described acquisition of histoplasmosis by Canadian travelers – two involving cave exposure.

In the following screen-shot, the frame to the left displays an interactive chronicle of cross-border histoplasmosis.  Users can sort data by year of event, country of exposure / origin, etc.  In this example I’ve selected “Setting” in order to study cases related to “cave exposure.”  Additional details and electronically-linked references appear when the user clicks on “Show event notes”


  1. Gideon Online.
  2. Berger S. Histoplasmosis: Global Status, 2019. Gideon e-books,
  3. Berger S. GIDEON Guide to Cross Border Infections, 2019. 256 pages, 134 tables, 4,543 references.

Note featured on ProMED

Bolivian Hemorrhagic Fever

In 2019, a small outbreak of Bolivian hemorrhagic fever was reported at a hospital in La Paz, Bolivia.  The following background data on Bolivian hemorrhagic fever are abstracted from Gideon and the Gideon e-book series. [1,2]  Primary references are available from the author.

Bolivian hemorrhagic fever (BHF) is caused by Machupo virus (Arenaviridae, Tacaribe complex, Mammarenavirus).  The disease was initially described in 1959 as a sporadic hemorrhagic illness in rural areas of Beni department, eastern Bolivia; and the virus itself was first identified in 1963.  BHF is most common during April to July in the upper savanna region of Beni.  Principal exposure occurs through rodents (Calomys callosus) which enter homes in endemic areas.

BHF is one of several human Arenaviruses diseases reported in the Americas: Argentine hemorrhagic fever (Junin virus), Brazilian hemorrhagic fever (Sabia virus), Lymphocytic choriomeningitis, Venezuelan hemorrhagic fever (Guanarito virus) and Whitewater Arroyo virus infection.  (At least two related diseases are reported in Africa: Lassa fever and Lujo virus infection)

Infection of C. callosus results in asymptomatic viral shedding in saliva, urine, and feces; 50% of experimentally infected C. callosus are chronically viremic and shed virus in their bodily excretions or secretions.  C. callosus acquires the virus after birth, and start shedding it through their urine and saliva while suckling.  When mice acquire the virus as adults, they may develop immunity and no longer shed the virus.

Although the infectious dose of Machupo virus in humans is unknown, exposed persons may become infected by inhaling virus in aerosolized secretions or excretions of infected rodents, ingestion of food contaminated with rodent excreta, or by direct contact of excreta with abraded skin or oropharyngeal mucous membranes. Nosocomial and human-to-human spread have been documented.  Hospital contact with a patient has resulted in person-to-person spread of Machupo virus to nursing and pathology laboratory staff.

In 1994, fatal secondary infection of six family members in Magdalena, Bolivia from a single naturally acquired infection further suggested the potential for person-to-person transmission.

During December 2003 to January 2004, a small focus of hemorrhagic fever was reported in the area of Cochabamba. A second Arenavirus, Chapare virus, was recovered from one patient with fatal infection.

Early clinical manifestations consist of nonspecific signs and symptoms including fever, headache, fatigue, myalgia, and arthralgia.  Within seven days patients may develop hemorrhagic signs, including bleeding from the oral and nasal mucosa and from the bronchopulmonary, gastrointestinal, and genitourinary tracts. Case fatality rates range from 5% to 30%.

Ribavirin has been used successfully in several cases of BHF.  The recommended adult regimen is: 2.0 g IV, followed by 1.0 g IV Q6h X 4 days, and then 0.5 g Q8h X 6 days

Note that the etiologic agent and clinical features of BHF are similar to those of Argentine hemorrhagic fever (AHF).  Neurological signs are more common in AHF, while hemorrhagic diatheses are more common in BHF.  A vaccine available for AHF could theoretically be effective against BHF as well.


  1. Berger S. American Hemorrhagic Fevers: Global Status, 2019. Gideon e-books,
  2. Berger S. Infectious Diseases of Bolivia, 2019. 342 pages, 87 graphs, 495 references.

Note featured on ProMED


Measles: Correlation of Vaccine Uptake with Disease Rates

The following is a country-by-country analysis of measles reporting trends vs. vaccine uptake.  For purposes of consistency, incidence data and population statistics used to calculate rates per 100,000 will be limited to those published by the World Health Organization (WHO).  Resultant graphs were generated by Gideon and abstracted from the Gideon e-book series [1,2]  True estimates of vaccination update statistics are those published by WHO, in most cases available only since 1980.  Data published by the countries themselves were not used, to avoid possible bias or inconsistency when comparing data among countries. Historical disease data which precede 1980 have also been appended to graphs to further appreciate the impact of vaccination.

The reader will note that in virtually all cases, the presumed impact of vaccine uptake on disease incidence occurs when vaccine uptake exceeds 80%, and again when rates increase beyond 90%.   As such, the few countries which have not achieved 80% uptake, or have consistently reported >90% uptake since 1980 are excluded.  Graphs are not included for countries for which data are not reported, or reported only sporadically.

Individual graphs for 135 countries are presented below in alphabetical order.  In 127 (94%) of these, a clear relationship seems to exist between increasing vaccine uptake and decreasing rates of measles.  In eight cases, temporary “spikes” in disease incidence were reported during years of high vaccine uptake: Japan, Jordan, Republic of Korea, Seychelles, Solomon Islands, South Africa, Sri Lanka and Syria.

I have not attempted to perform a statistical analysis of this phenomenon, and cannot say with certainty that a confounding (third) factor does not exist.  Nevertheless, these graphs appear to indicate a favorable effect of vaccination on measles incidence.

Measles Vaccine Uptake vs. Disease rates (per 100,000)


  1. Gideon e-Gideon multi-graph tool,
  2. Berger S. Measles: Global Status, 2019. 548 pages , 538 graphs , 5,779 references. Gideon e-books,

Leptospirosis in Israel

The following background information on Leptospirosis in Israel is abstracted from Gideon and the Gideon e-book series. [1,2] Primary references are available from the author.

Leptospirosis is most common in agricultural settlements of the Galilee, during the months of June to September.  Reported disease incidence reached a peak of 81 cases in 1962, but have since decreased considerably. 48 cases were reported during 2002 to 2008 – including 20 travel-related cases (15 of these acquired in southeast Asia).  Rates per 100,000 have been comparable to those reported in the United States for the past three decades (see graph) [3]

During 1970 to 1973, the main infecting serovars of Leptospira interrogans were grippotyphosa (41%) and hebdomadis (31%).  Serovars hardjohebdomadis and grippotyphosa accounted for 79% of cases during the 1970’s, and 32% during 1985 to 1999.  Serovar. icterohaemorrhagiae accounted for 2% during the 1970’s, and 29% during 1985 to 1999.

14 fatal cases of leptospirosis were reported during 1954 to 2017, the most recent in 1999.

The following chart summarizes five outbreaks of leptospirosis reported from Israel.


  1. Berger S.  Leptospirosis: Global Status, 2018.  223 pages , 177 graphs , 1,840 references. Gideon e-books,
  2. Berger S. Infectious Diseases of Israel, 2018. 481 pages , 238 graphs , 1,503 references. Gideon e-books,
  3. Gideon e-Gideon multi-graph tool,

Note featured in ProMED


Disease Outbreaks due to Sprouts

As of June, 2018 the Gideon database ( chronicles 22,777 published Infectious Diseases outbreaks.  Sprouts were implicated in 13.4% of outbreaks which specify a disease vehicle (5.2% of salmonellosis outbreaks).  Salmonellae were responsible for 83% of outbreaks associated with sprouts.  The remainder were caused by Escherichia coli, Listeria monocytogenes or Bacillus cereus. [1]


1 Berger S. Gideon Guide to Outbreaks, 2018. 2,011 pages, 5,272 tables, 51,622 references. Gideon e-books,

New Video tutorials for Outbreaks, Surveys and Cross Border Events

Dr. Steve Berger has release new videos to review how to use the Outbreaks, Surveys and Cross Border Events Public Health features of GIDEON.

They are included below:

Norovirus Infection in South Korea

The following background information on Norovirus infection in South Korea was abstracted from Gideon and the Gideon e-book series. [1-3]  A computer-generated parsing program of PubMeD and ProMED identifies 22,521 published Infectious Diseases outbreaks.  735 of these outbreaks specify Norovirus as the disease agent.  South Korea accounts for 0.67% of all outbreaks, and for 1.5% of Norovirus outbreaks.  Details of the individual events are summarized in table 1.

Further analysis of these sources identified 59,774 prevalence / seroprevalence surveys.  745 of these surveys examine the prevalence of viral agents associated with gastroenteritis.  South Korea accounts for 18.6% of all Infectious Disease surveys, and 3.4% of surveys involving viral gastroenteritis. Details of surveys which examine Norovirus prevalence are summarized in table 2.

Primary references are available from the author.


  1. Berger SA. Infectious Diseases of South Korea, 2018. 418 pages, 108 graphs, 2,260 references. Gideon e-books,
  2. Berger SA. Gideon Guide to Outbreaks, 2018. 1,900 pages, 5,246 tables, 50,908 references.
  3. Berger SA. Gideon Guide to Surveys, 2018. 4,028 pages, 10,229 tables, 53,802 references.