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Preventing Foodborne Illness

Food quality control expert inspecting specimens of groceries in the laboratory
Food quality control expert inspecting groceries in the laboratory


Since 2019, World Food Safety Day is celebrated each year on the 7th of June,  to promote awareness regarding the need to develop and maintain food safety standards. These efforts are being done both to reduce the burden of foodborne disease and to minimize its impact on socio-economic systems.

Foodborne diseases constitute a major health issue worldwide. The World Health Organization (WHO) estimates that approximately 10% of the global population is infected by foodborne pathogens each year (1). Similar to other diseases, the severity of the foodborne illness varies with the type and the amount of exposure to the causative microorganism, as well as the disease-fighting potential of the affected individual.


Clinical Presentation of Foodborne Illnesses

Foodborne illnesses might manifest as acute diarrhea, nausea, etc., which usually resolves within 7 to 10 days; or as chronic and potentially fatal diseases such as botulism or typhoid fever.

Botulism, a common and potentially fatal disease, is caused by Clostridium botulinum. Signs and symptoms usually appear within 18 to 36 hours of food ingestion Bacterial toxins can persist in the patient’s blood for up to 12 days. Common findings include respiratory failure and neurological symptoms, such as blurred vision, paralysis, etc. (2). 


Foodborne cases of botulism in the United States 1979-2019


Botulism cases in US, 1979 - 2020, GIDEON graph


Prevention and Management of Foodborne Illnesses

irradiated spinach_byMikeLichtContamination of food or food products can occur at various stages of production, including growth, processing, transportation, or storage. Thus, there is a critical need to adopt appropriate measures that correspond to these variable conditions to maximize food safety and minimize the transmission of foodborne illnesses.


1.     Decontamination of Fresh Produce

With rapid globalization, fresh produce is now available worldwide throughout the year in the form of frozen food.  Fresh produce must undergo proper decontamination before being frozen – to prevent such diseases as norovirus infection and hepatitis A (3, 4). Some of the common techniques used for decontamination include (5):

a.     Application of antibiotics during the growth stage

b.     Proactive sampling for detection of pathogens

c.     Bacteriocins (bacteria-generated toxins to kill the competitive strains)

d.     Antimicrobial natural products and nanoparticles

e.     Bacteriophages

f.      Irradiation 

Alternatively, consumers might receive probiotics and relevant vaccines to protect them from relevant foodborne illnesses.


2.     Development of Public Health Surveillance Systems

A competent public health surveillance system should be implemented by the Governmental and related organizations to identify impending outbreaks in order to facilitate effective policies and goals (6, 7). Such systems help control and prevent extensive transmission by collecting and analyzing epidemiological and clinical data that provide guidelines to take appropriate measures.


3.     Prophylactic Measures for People with Increased Susceptibility to Foodborne Illnesses

People who are vulnerable to foodborne infections, such as older adults, infants – and individuals with prior diseases of the immune system, liver, gastrointestinal tract, etc. should be particularly vigilant and observed preventive measures (8) including: 

a.   Adherence to a low-microbial diet and avoidance of undercooked meat, unpasteurized milk, etc.

b.  Consumption of  bottled natural water

c.   Infants should be preferably given sterile ready-to-eat formula; powdered formula should be reconstituted in boiling water and given in boiled water-  sterilized bottles

d.  Antimicrobial may be administered prophylactically during transplantation and other high-risk treatments.


4.     Food Safety Measures

In general, people should adopt safe food practices wherever they cook and consume food or food products (9). The cooking utensils/surfaces should be properly cleaned and sanitized. Raw and undercooked foods should be stored separately to avoid cross-contamination. Food should be cooked or reheated thoroughly, meats and seafood should be cooked to appropriate temperatures. Cooked food should be stored at < 5°C, and not for prolonged periods. Only clean, purified water should be used for cooking food to minimize any chances of waterborne infection. Raw fruits and vegetables should be properly washed before consumption.

Woman washing carrots and pomegranate in a metal sink
Raw fruits and vegetables should be properly washed before consumption.


At the Public Health level, comprehensive integration of government-issued guidelines and self-monitoring are needed to prevent and control foodborne illnesses.


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  1.     “Foodborne diseases”, World Health Organization. [Online]. Available:
  2.     “Botulism”, GIDEON Informatics, Inc, 2021 [Online]. Available:
  3.     Nasheri N, Vester A, Petronella N. Foodborne viral outbreaks associated with frozen produce. Epidemiol Infect. 2019 Oct;147:e291. doi: 10.1017/S0950268819001791.
  4.     Chapman B, Gunter C. Local Food Systems Food Safety Concerns. Microbiol Spectr. 2018 Apr; 6(2). doi: 10.1128/microbiolspec.PFS-0020-2017.
  5.     Yang SC, Lin CH, Aljuffali IA, Fang V. Current pathogenic Escherichia coli foodborne outbreak cases and therapy development. Arch. Microbiol. 2017 June; 199(6): 811-825.
  6.     Ward H, Molesworth A, Holmes S, Sinka K. Public health: surveillance, infection prevention, and control. Handb Clin Neurol. 2018; 153:473-484. doi: 10.1016/B978-0-444-63945-5.00027-1.
  7.     Hoelzer K, Moreno Switt AI, Wiedmann M, Boor KJ. Emerging needs and opportunities in foodborne disease detection and prevention: From tools to people. Food Microbiol. 2018 Oct; 75:65-71. doi: 10.1016/
  8.     Lund BM, O’Brien SJ. The occurrence and prevention of foodborne disease in vulnerable people. Foodborne Pathog Dis. 2011 Sep; 8(9):961-73. doi: 10.1089/fpd.2011.0860.
  9.     “Five keys to safer food manual”, World Health Organization [Online]. Available:

What to Do When Faced With a Fungal Infection at Home

Woman looking at black mold (fungal infection) on the ceiling

written exclusively for by Jennifer Birch


Fungal infections are a rampant problem in America. According to the Center for Disease Control and Prevention (CDC), there were over 75,000 hospitalizations for fungal disease in 2017. However, this figure is most likely an underrepresentation, given that fungal infections go largely undiagnosed. Regardless, some of them can cause illness and even death if left untreated. Individuals should be aware of the signs, treatment options, and prevention methods for fungal infections.


What is a fungal infection?

Fungi cause fungal infections. Most relate this type of microorganism to mushrooms, but they also come in the form of mold, mildew, and yeast. When a harmful fungus comes into contact with your skin, especially through an open wound, it can cause an infection. Some types of fungi also release tiny spores into the air as a means of reproduction. Inhaling these spores can also cause a fungal infection to spread in your lungs.

Given that there are multiple types of fungi, it follows that there are also many different diseases that stem from the initial infection. One example is Candidiasis, which is caused by yeast – the most common cause of fungal infections worldwide. Other fungal diseases include dermatophytosis, endemic mycoses, and a whole slew of mold-based illnesses.

Regardless of the cause, fungal infections are usually characterized by redness, itching, irritation, and even swelling of the skin. It can be very uncomfortable for anyone who experiences it and must be treated immediately.


What are the treatment options?

Most fungal infections will go away with the use of over-the-counter treatments. These include antifungal creams, gels, sprays, and ointments.

However, if it doesn’t improve even after medication, it’s best to seek medical assistance. When visiting your local clinic, you will likely be attended to by a nurse knowledgeable in this area. Most specialist nurses have completed an RN to BSN program, which qualifies them as primary care professionals who can diagnose various conditions, including superficial fungal infections. Note down recommendations made by your nurse regarding treatment and future techniques for prevention against fungal infections.

However, if  infection becomes more serious, prepare to be directed to a dermatologist or an Infectious Disease specialist. After evaluating the area of infection, they will likely prescribe a more potent antifungal cream than you can’t get over the counter. For fungal infections that have begun to spread throughout your body, they might administer an antifungal injection and prescribe oral medication. Make sure to keep in touch with your doctor throughout the treatment process to ensure that the infection isn’t getting worse.


Prevention is better than cure

Plenty of fungi thrive in hot and humid weather, especially mold. So, to prevent more fungal infections in the future, you need to ensure your home is clean and dry. Properly ventilate rooms, so moisture doesn’t build up inside. It’s also worth investing in air conditioning units and dehumidifiers to further improve air quality at home. Finally, should you find any mold or mildew growing in your house and deal with it immediately, so it doesn’t propagate further.

In addition to keeping your home clean, you should also practice good personal hygiene. This simply means wearing clean clothes and taking baths regularly. At the end of the day, protecting your home against fungus and keeping your body clean is the surest way to prevent fungal diseases.

Would you like to learn more? Check out our in-depth review of fungal infections by Dr. Moskow here.


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Congenital Infections: TORCH

by Dr. Jaclynn Moskow

Pregnant woman cuddling her belly
By obtaining proper prenatal and perinatal care, pregnant women can optimize their chances of preventing, detecting, and treating congenital infections.


Congenital infections are caused by pathogens transmitted from a mother to her offspring during pregnancy or delivery. These infections can cause significant fetal and neonatal morbidity and mortality. The mnemonic “TORCH” is often used to refer to common congenital infections:


T – Toxoplasma

O – Other (Syphilis, Parvovirus B19, Varicella-Zoster, etc)

R – Rubella


H – Herpes Simplex Virus


Congenital Toxoplasmosis

Congenital toxoplasmosis is caused by the parasite Toxoplasma gondii. It can be acquired when a pregnant woman consumes raw or undercooked meat, or contacts contaminated water, soil, or cat feces (generally from outdoor cats that hunt.) The classic triad of congenital toxoplasmosis is 1) chorioretinitis 2) hydrocephalus and 3) cerebral calcifications. 

Symptoms often do not occur until months after birth and may include seizures, cognitive impairment, and cerebellar dysfunction (1). The retinal disease associated with congenital toxoplasmosis is progressive. Other clinical manifestations may include fever, rash, hydrocephalus or microcephaly, sensorineural hearing loss, congenital nephro­sis, hematologic abnormalities, hepatosplenomegaly, various endocrinopathies, and myocarditis. Infection can lead to spontaneous abortion, prematurity, stillbirth, and perinatal death. 

Congenital toxoplasmosis is more severe when acquired in early pregnancy. The incidence is highest in the Eastern Mediterranean and Africa (2). Rates are estimated at 1 per 3000-10000 live births in the United States (3) and 6.7 per 10000 live births in Europe – with 81% of all confirmed cases in the EU/EEA occurring in France (4). Spiramycin can decrease the risk of vertical transmission, but will not treat the fetus if the infection has already occurred. Infants born with this disease may benefit from pyrimethamine, sulfadiazine, and leucovorin. 

To help prevent infection, pregnant women should avoid consuming raw and undercooked meat, wear gloves when gardening, and avoid changing cat litter.


Congenital Rubella

Rubella, also known as “German measles,” is caused by the Rubella virus (Togaviridae family). It is most severe when acquired during the first trimester of pregnancy when the maternal infection will lead to fetal demise in 40-90% of cases (5). Congenital rubella can cause cardiac abnormalities, including patent ductus arteriosus and pulmonary artery stenosis. It can also cause ophthalmic abnormalities such as cataracts, glaucoma, retinopathy, and microphthalmia. Sensorineural deafness is common, and microcephaly, cognitive impairment, and meningoencephalitis may occur. Hepatosplenomegaly, hepatitis, hemolytic anemia, and thrombocytopenic purpura may also be observed. 

The incidence of congenital rubella has plummeted in countries that employ widespread vaccination. In recent times, documented cases of rubella in the United States are virtually all imported. Cases and outbreaks continue in Europe but at a very low rate. In 2008, 48% of all cases occurred in Southeast Asia and 38% in Africa (6). There is no effective treatment for congenital rubella.


Regional comparison of Congenital Rubella Syndrome prevalence, 1999 – 2019

Congenital infections - Congenital Rubella Syndrome prevalence: comparison between regions worldwide, 1999 - 2019


Congenital CMV

Congenital cytomegalovirus (CMV) is the most common congenital viral infection in the developed world. Clinical manifestations include sensorineural hearing loss, visual impairment, cerebral palsy, and cognitive difficulty. It can also cause neonatal cholestasis, pulmonary hypertension, and epilepsy. 10-20% of all hearing impairment in children is caused by congenital CMV (7).

CMV is identified in 5 to 7 per 1000 live births in the USA, Canada, Western Europe, and Australia; and 10-30 per 1000 live births in Latin America, Africa, and most Asian countries (8). Symptomatic infants may benefit from treatment with valganciclovir. It is difficult to prevent the acquisition of CMV, but some have suggested that pregnant women can decrease risk by avoiding contact with the saliva and urine of young children.


Congenital HSV

Congenital herpes simplex virus (HSV) most commonly occurs when an infant is exposed to the mother’s genital tract during delivery. Both herpes simplex-1 and herpes simplex-2 can cause congenital HSV. The risk of transmission from mother to infant depends primarily on when the maternal infection was acquired. When a mother is infected close to the time of delivery, the fetal infection rate is estimated at 25-60%. This rate drops to less than 2% when a mother is infected during the first half of pregnancy or earlier (9).

Signs of congenital HSV infection may occur between birth and six weeks of age. Disseminated disease may involve the liver, lung, central nervous system, and skin. “SEM disease” is limited to the skin, eyes, and/or mouth. Congenital HSV may cause a vesicular rash, hypothermia, lethargy, seizures, respiratory distress, hepatosplenomegaly, thrombocytopenia, hepatic dysfunction, cerebrospinal fluid pleocytosis, and sepsis. Congenital HSV is fatal in 50% of cases (10). The incidence of congenital HSV is estimated to be between 1 in 3000-20000 live births. All pregnant women should be tested for HSV, and those who are positive should receive prophylactic acyclovir or a similar drug at the time of delivery. Infected infants should be treated as well.


Congenital Syphilis

Congenital syphilis occurs when the bacterium Treponema pallidum is transmitted transplacentally or via the birth canal. The rate of vertical transmission increases as the pregnancy advances and transmission is more likely when the mother is experiencing early disease (11). Congenital syphilis can sometimes be detected by the appearance of nonimmune hydrops fetalis on ultrasound examination.

Congenital syphilis may be divided into two clinical syndromes: early congenital syphilis and late congenital syphilis. The early disease manifests within the first two years of life and is characterized by rash, adenopathy, and hepatosplenomegaly. Mucous patches and condylomata lata may be seen.  The eyes may be affected, and cranial nerve palsy and seizures may occur. Thrombocytopenia with petechiae and purpura are often noted. Other manifestations can include anemia, myocarditis, pancreatitis, nephrotic syndrome, and malabsorption. Osteochondritis is often seen on imaging. 

Late congenital syphilis manifests after two years of age. Dental findings include “Hutchinson’s teeth” and “mulberry molars.” Interstitial keratitis and eighth cranial nerve deafness can occur. Rhagades may be seen. Bone and joint abnormalities may include frontal bossing, saddle nose deformity, protuberant mandible, short maxilla, high palatal arch, sternoclavicular joint thickening (Higouménakis sign), saber shin, and Clutton’s joints. Central nervous system involvement can include cognitive impairment, hydrocephalus, seizures, cranial nerve palsy, paralysis, and optic nerve atrophy.


Congenital infections, Syphilis in the United States, 1941 – 2019


Graph illustrating the prevalence of congenital infection - Syphilis in the United States, 1941 - 2019


The WHO estimates that there were approximately 661,000 total cases of congenital syphilis in 2016, resulting in over 200,000 stillbirths and neonatal deaths (12) – with most cases occurring in South America and Africa. The CDC reports that congenital syphilis is on the rise in the United States, with the number of cases in 2018 being highest since 1998 (13).

All pregnant women should be tested for syphilis at their first prenatal visit. Penicillin is the only known effective antimicrobial agent for the prevention of vertical transmission and treatment of fetal and neonatal infection.


Congenital Parvovirus B19

Parvovirus B19 is estimated to infect 1-5% of pregnant women. Most infections are without consequence to the fetus, but in rare cases, serious fetal disease can arise (14). In infected fetuses, ultrasound may show nonimmune hydrops fetalis. 

Congenital parvovirus B19 often causes severe anemia and may also cause thrombocytopenia. Neurological manifestations include hydrocephalus, cerebellar hemorrhage, and polymicrogyria. Cardiac complications can include Ebstein’s anomaly, ventricular septal defect, cardiomyopathy, second‐degree heart block, and myocarditis. Ocular involvement may include corneal opacification, aphakia, and microphthalmia. Gastrointestinal manifestations include meconium peritonitis, fetal liver calcifications, portal tract fibrosis, and hypoplasia of the abdominal muscles. Congenital parvovirus B19 can also cause cleft lip and palate, micrognathia, bifid scrotum, secundum atrial septal defect, and micropenis with perineoscrotal hypospadias.

Intrauterine fetal blood transfusion can be used to treat the severe fetal anemia associated with congenital parvovirus B19 infection. 


Congenital Varicella-Zoster

Varicella-zoster congenital infections are caused by the virus that causes chickenpox and shingles. Infection may be characterized by low birth weight, hypoplasia of the extremities, dermal scarring, focal muscular atrophy, encephalitis, cortical atrophy, chorioretinitis, and microcephaly. Neonatal varicella zoster may occur when a mother contracts varicella virus between five days before delivery – to 48 hours after delivery. Neonatal varicella has a fatality rate of up to 30% (15). Congenital Varicella-Zoster virus infection is rare since most women are immune by childbearing age – having either been infected during childhood or vaccinated. Infants born with congenital varicella zoster may improve with acyclovir. 


Additional Congenital Infections

Additional viral agents of fetal and neonatal morbidity and mortality include HIV, Hepatitis B and C, measles, enteroviruses, adenovirus, lymphocytic choriomeningitis virus, West Nile virus, Zika virus, and Chikungunya virus. Additional bacterial causes include Group B Streptococcus, Chlamydia trachomatis, Neisseria gonorrhoeae, , Escherichia coli, Mycobacterium tuberculosis, and Coxiella burnetii. A parasite, Plasmodium falciparum (the causative agent of malaria) is also associated with congenital infection. 

By obtaining proper prenatal and perinatal care, pregnant women can optimize their chances of preventing, detecting, and treating congenital infections. 


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(1) Hampton MM. Congenital Toxoplasmosis: A Review. Neonatal Netw. 2015;34(5):274-8. doi: 10.1891/0730-0832.34.5.274.

(2) Rostami A, Riahi SM, Contopoulos-Ioannidis DG, Gamble HR, Fakhri Y, Shiadeh MN, Foroutan M, Behniafar H, Taghipour A, Maldonado YA, Mokdad AH, Gasser RB. Acute Toxoplasma infection in pregnant women worldwide: A systematic review and meta-analysis. PLoS Negl Trop Dis. 2019 Oct 14;13(10):e0007807. doi: 10.1371/journal.pntd.0007807.

(3) McAuley JB. Congenital Toxoplasmosis. J Pediatric Infect Dis Soc. 2014 Sep;3 Suppl 1(Suppl 1):S30-5. doi: 10.1093/jpids/piu077.

(4) “Congenital toxoplasmosis – Annual Epidemiological Report for 2016”, European Centre for Disease Prevention and Control, 2021. [Online]. Available: 

(5) Best JM. Rubella. Semin Fetal Neonatal Med. 2007 Jun;12(3):182-92. doi: 10.1016/j.siny.2007.01.017. 

(6) Bouthry E, Picone O, Hamdi G, Grangeot-Keros L, Ayoubi JM, Vauloup-Fellous C. Rubella and pregnancy: diagnosis, management and outcomes. Prenat Diagn. 2014 Dec;34(13):1246-53. doi: 10.1002/pd.4467. 

(7) Goderis J, De Leenheer E, Smets K, Van Hoecke H, Keymeulen A, Dhooge I. Hearing loss and congenital CMV infection: a systematic review. Pediatrics. 2014 Nov;134(5):972-82. doi: 10.1542/peds.2014-1173. 

(8) Fowler KB, Boppana SB. Congenital cytomegalovirus infection. Semin Perinatol. 2018 Apr;42(3):149-154. doi: 10.1053/j.semperi.2018.02.002.

(9) Fernandes ND, Arya K, Ward R. Congenital Herpes Simplex. 2021 Jan 11. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan–. PMID: 29939674.

(10) Westhoff GL, Little SE, Caughey AB. Herpes simplex virus and pregnancy: a review of the management of antenatal and peripartum herpes infections. Obstet Gynecol Surv. 2011 Oct;66(10):629-38. doi: 10.1097/OGX.0b013e31823983ec.

(11) Cooper JM, Sánchez PJ. Congenital syphilis. Semin Perinatol. 2018 Apr;42(3):176-184. doi: 10.1053/j.semperi.2018.02.005.

(12) “WHO publishes new estimates on congenital syphilis”, World Health Organization, 2021. [Online]. Available:

(13) “STD Facts – Congenital Syphilis”,, 2021. [Online]. Available:

(14) Ornoy A, Ergaz Z. Parvovirus B19 infection during pregnancy and risks to the fetus. Birth Defects Res. 2017 Mar 15;109(5):311-323. doi: 10.1002/bdra.23588. 

(15) “GIDEON”,, 2021. [Online]. Available:

Examining Salmonella Typhi and Typhoid Fever

by Dr. Jaclynn Moskow

Typhoid fever refers to the disease caused by Salmonella typhi (Salmonella enterica subsp. enterica serovar Typhi), a facultative anaerobic Gram-negative bacillus. Both typhoid fever and its close relative paratyphoid fever are sometimes referred to as “enteric fever.” As the name enteric fever implies, the illness is often characterized by gastrointestinal symptoms and fever.

Green houseflies feeding on ripe mango using their labellum to suck the meat


Humans are the only natural reservoir for Salmonella typhi, and transmission occurs via the fecal-oral route. Transmission may occur after eating food that was prepared by someone carrying the bacterium or after using a contaminated toilet and failing to follow proper hand hygiene. Transmission can also occur by drinking water contaminated by sewage, or by eating food prepared in contaminated water. Flies can carry the bacteria from sewage to food.

The average incubation period for typhoid fever is 15 to 21 days, but symptoms may develop as soon as 5 days post transmission or as late as 34 days. Both children and adults contract typhoid fever. In some outbreaks, typhoid fever has primarily affected school-aged children, with cases in infants and toddlers being quite rare. In recent years, very young children have also proven extremely susceptible to the disease.[1]

Chronic Carriers and the Case of Typhoid Mary

Salmonella typhi may continue to shed in feces after a patient has recovered from the disease, and such individuals may become asymptomatic carriers of the bacteria. Approximately five percent of people who contract Salmonella typhi infection will become chronic carriers. 25% of carriers experienced no signs or symptoms of the disease.[2]  Females are more likely than males to become chronic carriers.  In chronic carriers, Salmonella typhi takes refuge in macrophages [3] and the gall bladder.

The most infamous carrier of typhoid fever was Mary Mallon, also known as “Typhoid Mary.” Mary was born in Ireland and immigrated to New York at the turn of the 20th century. She worked as a cook for eight affluent families, seven of which contracted Typhoid Fever.[4] These high-profile infections eventually led to an investigation and to Mary’s forced quarantine. After her release, she defied orders and continued to work as a cook, using various aliases. She stopped working for private clients and worked instead at several public restaurants as well as at Sloane Maternity Hospital.

51 cases of typhoid fever were traced to Mary, including three fatalities. [5] It is likely that Mary actually infected and killed many times this amount. In 1915, she was located and detained a second time, eventually dying after a period of 23 years in forced quarantine. Mary never believed she was the source of any infections, as she had no symptoms of the disease.

Signs and Symptoms

Typhoid fever can have a very nonspecific clinical presentation. Generally, initial enterocolitis develops, without associated fever. Patients may experience constipation or diarrhea, associated with abdominal pain and vomiting. Hematochezia may occur. Hepatosplenomegaly is present in 50% of cases and jaundice may also develop. Some patients develop cholecystitis or pancreatitis.

A short asymptomatic phase may proceed with the onset of fever.  Once fever develops, it often follows a “step-ladder” pattern, rising and subsequently falling before rising again. Additional flu-like symptoms may include chills, diaphoresis, headache, sore throat, cervical lymphadenopathy, cough, and myalgia. Pneumonia may develop and bradycardia is often noted. During the second week of illness, 30% of patients develop a rash referred to as “rose spots.” Initial leukocytosis is often seen, followed by leukopenia. Thrombocytopenia, coagulopathy, and hepatic dysfunction may also be noted.

Some patients will go on to develop an intestinal perforation, generally in the 3rd or 4th week of illness. Intestinal perforation is more common in males than in females. Typhoid fever is dangerous for pregnant women, with 70% of untreated cases ending in miscarriage. Additionally, transmission from mother to fetus and subsequent neonatal typhoid can occur.

Systemic inflammation may lead to such complications as myocarditis, endocarditis, pericarditis, and mycotic aneurysm. Some patients develop meningitis or encephalitis. Spondylitis/spondylodiscitis, rhabdomyolysis, and hemophagocytic lymphohistiocytosis have also been seen – as have endophthalmitis, cranial nerve palsy, and Guillain-Barre syndrome.

Typhoid fever can induce neuropsychiatric symptoms. Encephalopathy occurs in 21% of cases. Psychosis or confusion occurs in 5 to 10%. Seizures and coma occur less commonly. The term “typhoid state” (from the Greek word “typhos” –  meaning “clouded”) is sometimes used to refer to changes in mental status.

Without treatment, symptoms of typhoid fever will generally resolve in approximately one month. About ten percent of patients with typhoid fever will experience relapse, more common among those who received treatment than those who did not. Typhoid fever is more severe among patients with HIV infection, malaria, and sickle cell anemia. Long-term carriers have a higher incidence of cancers of the gallbladder, pancreas, colon, and lung. The case-fatality rate for untreated typhoid fever is approximately 15% – vs. 0.8% with treatment.

Illustration of typhoid fever

Diagnosis and Treatment

Diagnosis is made via culture of blood, urine, sputum, or bone marrow. Stool cultures are often negative except in very late infection. Previously, the Widal test was used to detect serum antibody titers against Salmonella typhi O and H antigens. However, this test has a high rate of both false negatives and false positives and is thus unreliable. 

Both Ceftriaxone and Azithromycin can be used to treat typhoid fever. Fluoroquinolones are no longer recommended, in view of the emergence of resistant strains. Corticosteroids may be used when there is evidence of widespread systemic involvement. Health-care personnel should follow stool precautions. Most carriers can be cured with antibiotics. Carriers with cholelithiasis usually remain positive after antibiotic treatment and will require cholecystectomy.


Over the last three decades, typhoid fever has affected between 11 to 21 million people per year, worldwide.  Incidence has been declining in many countries. 

Typhoid, estimated cases worldwide 1990 - today

The countries reporting most cases include Bangladesh, China, India, Indonesia, Laos, Nepal, Pakistan, and Vietnam. High rates also occur in Africa and Central and South America. If you have a GIDEON account, click to explore the typhoid fever outbreak map. 

The CDC reports that approximately 350 people in the United States receive treatment for typhoid fever each year and that as many as 5,700 people are likely to be infected.[6]  Most cases in the United States result from travel to endemic areas. Occasionally, cases arise from other sources, such as from contaminated imported food. A review of outbreaks in the United States can be found here.


Cases of typhoid fever and other waterborne diseases will decline as access to clean water increases and as sanitary conditions improve.  The CDC recommends receiving a typhoid fever vaccine prior to travel to countries with high incidence. Both oral and injectable vaccines are available – both with approximately 50 to 80% efficacy in preventing disease. When traveling, precautions should include adherence to proper hand hygiene, drinking only bottled water, and avoiding uncooked food.

Paratyphoid Fever and Typhus

Typhoid fever is clinically similar to Paratyphoid fever and some forms of Typhus. Paratyphoid fever is a form of enteric fever caused by a Salmonella paratyphi (Salmonella enterica serotypes Paratyphi A, Paratyphi B, or Paratyphi C). Clinically, it may be indistinguishable from typhoid fever and it is transmitted via the same routes. Salmonella paratyphi causes fewer cases of enteric fever than Salmonella typhi

Typhus refers to diseases caused by Rickettsia typhi, Rickettsia prowazekii, and Orientia tsutsugamushi.  Typhus is transmitted by fleas, mites, or lice. During the 19th century, typhoid and typhus were believed to be two forms of a single disease. Like typhoid fever, typhus usually causes flu-like symptoms and a rash, and often with gastrointestinal symptoms. The various forms of typhus are less common than typhoid – and are each reported in specific geographical regions. 

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[1] A Sinha, S Sazawal, R Kumar, et al., “Typhoid fever in children aged less than 5 years”, Lancet, vol. 28, num. 354, pp. 734-7, 1999. Available: 10.1016/S0140-6736(98)09001-1

[2] C Parry, T Hien, G Dougan, et al., “Typhoid fever”, N Engl J Med, vol. 347, num. 22, pp. 1770-82, 2002. Available: 10.1056/NEJMra020201

[3] N Eisele, T Ruby, A Jacobson et al., “Salmonella require the fatty acid regulator PPARδ for the establishment of a metabolic environment essential for long-term persistence”, Cell Host Microbe, vol. 14, num. 2, pp. 171-182, 2013. Available: 10.1016/j.chom.2013.07.010

[4] Marineli F, Tsoucalas G, Karamanou M, Androutsos G. Mary Mallon (1869-1938) and the history of typhoid fever. Ann Gastroenterol. 2013;26(2):132-134. [Online]. Available:

[5] “’Typhoid Mary’ Dies Of A Stroke At 68. Carrier of Disease, Blamed for 51 Cases and 3 Deaths, but Immune”, The New York Times, November 12, 1938. [Online]. Available:

[6] Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Foodborne, Waterborne, and Environmental Diseases (DFWED), “Typhoid Fever and Paratyphoid Fever: Questions and Answers”. [Online]. Available: 

Pathogen of the Month: Yersinia Pestis

by Dr. Jaclynn Moskow

The most researched pathogen on GIDEON in January was Yersinia pestis, a facultative anaerobic, Gram-negative, coccobacillus. It is the causative agent of the Plague and responsible for some of the most deadly pandemics in history.  While Yersinia pestis is no longer a cause of mass mortality, outbreaks do still occur. Over the last decade, there have been up to 2,000 cases per year reported to the World Health Organization, and likely thousands more unreported.[1]

Yersinia pestis illustration
Yersinia pestis – the agent of Plague


Rodents are the natural reservoirs for Yersinia pestis, including rats, mice, squirrels, chipmunks, voles, prairie dogs, and marmots. The bacteria can also be transmitted to a wide variety of other mammals, including rabbits, coyotes, sheep, and cats. There are currently animals carrying Yersinia pestis on all continents except for Oceania.[2]

Fleas transmit Yersinia pestis from animals to humans, and flea bites are the most common route of infection for humans. Humans can also become infected by coming into contact with fluid or tissue. For example, this could happen when a hunter skins a diseased animal. When respiratory infection occurs, Yersinia pestis can become airborne and spread between humans. In rare cases, Yersinia pestis has been contracted via ingestion of infected meat. Dr. Berger discusses transmission here

Both children and adults are at risk of becoming sick with Plague, and there does not appear to be a significant difference in infection rates between men and women.

Yersinia pestis in history

Yersinia pestis likely emerged around 6,000 years ago, evolving from a close relative – Yersinia pseudotuberculosis. [3] The first major Plague pandemic occurred in the 6th century and is known as The Justinian Plague. The disease spread throughout Europe, Asia, and North Africa by way of ship. Its death toll is disputed, with some researchers estimating it claimed half the world’s population and others believing it was less severe.[4]

The second major Plague pandemic occurred between 1346 and 1353, once again striking Europe, Asia, and North Africa. This outbreak, known as The Black Death, took the lives of 75 to 200 million people. It decimated cities quickly upon arrival, sometimes killing over half the population in just a few weeks. In Ragusa, a Venetian port city, incoming sailors were isolated for 40 days, a practice which was known as a “quarantino” …the origin of the word “quarantine”.[5]

Images of physicians wearing bird-like beak masks are often associated with The Black Death. Microbes had yet to be discovered, and many doctors believed Plague was transmitted through smell. To combat this smell, the beak mask had a space for flowers, herbs, and spices. This mask, however, was actually not invented during The Black Death, but rather during a different Plague outbreak in 1619. After the Black Death subsided, Plague outbreaks continued in Europe every few years for the next 300 years, culminating with “The Great Plague” of London in 1665.



The next significant Plague pandemic occurred in 1894, originating in China, spreading through Asia and Europe, and eventually arriving in the United States in 1900. In 1894 Swiss physician Alexandre Yersin and Japanese physician Kitasato Shibasaburō simultaneously discovered the bacterial origin of Plague. Yersin named the bacterium Pasteurella pestisSoon after, fleas were identified as a vector of transmission. Pasteurella pestis was renamed Yersinia pestis in 1944. Notable 20th-century plague outbreaks occurred in Los Angeles between 1924 to 1925 and in Vietnam from 1965 to 1975.

Bubonic Plague

There are 3 main types of Plague, with Bubonic Plague being the most common type. Bubonic Plague is transmitted via flea bites or via the handling of tissue or fluids. It has an incubation period of 2-to-6 days. Bacteria multiply in lymph nodes close to the site of infection. A maculopapular lesion may appear at the infection site. The lymph nodes become painful and swollen and are known as “Buboes.” Buboes are usually inguinal (60% to 90%), axillary (30%), cervical (10%), or epitrochlear (10%). Other symptoms of Bubonic Plague are flu-like, including fever, headache, chills, pharyngitis, muscle aches, extreme weakness, and tachycardia. Without treatment, Bubonic Plague has a mortality rate of around 50-60%. With treatment, this drops to about 10%. Human to human transmission of Bubonic Plague is extremely rare.


Bubonic plague transmission - illustration


Pneumonic Plague

Pneumonic Plague occurs when Yersinia pestis enters the lungs. This can happen from inhaling respiratory droplets, or from the bloodstream during untreated Bubonic Plague. The incubation period when the bacteria is inhaled is 1-to-3 days. Pneumonic Plague presents with fever, headache, weakness, tachycardia, coughing, chest pain, and shortness of breath. Hemoptysis is common. With treatment, it has a fatality rate of around 15%. Untreated Pneumonic Plague is almost always fatal.

Septicemic Plague

When Yersinia pestis enters the bloodstream, Septicemic Plague can occur. This may happen directly from a flea bite, or as a complication of untreated Bubonic or Pneumonic Plague. Septicemic Plague may begin with flu-like symptoms. Additionally, it may cause nausea, vomiting, diarrhea, abdominal pain, and sometimes hematemesis and/or hematochezia. Acrocyanosis, ecchymosis, petechiae, and digital gangrene may be noted. Septicemic Plague may progress to cause meningitis, osteomyelitis, kidney failure, DIC, and septic shock. The fatality rate is around 28% with treatment and around 100% if untreated.

Rare forms of Plague include cutaneous, pharyngeal, meningeal, and gastrointestinal.

Diagnosis and treatment

A presumptive diagnosis of Plague may be made through isolation of Yersinia pestis from pus, blood, sputum, or other infected material. 

When Plague is suspected, treatment should be initiated prior to laboratory confirmation. Gentamicin, Streptomycin, Doxycycline, and Chloramphenicol are all effective. Patients with Plague should be isolated. When Pneumonic Plague is suspected, standard respiratory droplet precautions should be followed. Individuals exposed to Plague patients should begin prophylaxis. 


Today, there are approximately 1,000 to 2,000 reported cases of Plague globally each year – and 100 to 200 deaths.

Plague deaths worldwide, GIDEON graph


About 95% of current Plague cases occur in Madagascar and the Democratic Republic of Congo.  Brazil, Myanmar, Peru, Vietnam, and The United States also report cases almost every year. If you have a GIDEON account, click to explore Plague outbreak map

According to the CDC, about 7 people in the United States contract Plague each year, with the areas reporting cases usually being Northern New Mexico, Northern Arizona, Southern Colorado, Southern Oregon, Western Nevada, and various rural and semi-rural parts of California.

In 2009, University of Chicago scientist Malcolm Casadaban contracted Plague while conducting vaccine research and unfortunately died. Between 2019 and 2020 there were at least 5 cases of Plague in China linked to eating marmot meat and a few others of unknown origin.



People who live in areas with Plague outbreaks can take precautions to minimize the risk of infection. The CDC recommends the following:

  • Reduce rodent habitat around your home, workplace, and recreational areas. Remove brush, rock piles, junk, cluttered firewood, and possible rodent food supplies, such as pet-  and wild anima- food. Make your home and outbuildings rodent-proof.
  • Wear gloves if you are handling or skinning potentially infected animals to prevent contact between your skin and the plague bacteria. Contact your local health department if you have questions about disposal of dead animals.
  • Use repellent if you think you could be exposed to rodent fleas during activities such as camping, hiking, or working outdoors. Products containing DEET can be applied to the skin as well as clothing and products containing permethrin can be applied to clothing (always follow instructions on the label).
  • Keep fleas off of your pets by applying flea control products. Animals that roam freely are more likely to come in contact with plague infected animals or fleas and could bring them into homes. If your pet becomes sick, seek care from a veterinarian as soon as possible
  • Do not allow dogs or cats that roam free in endemic areas to sleep on your bed.

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[1] Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases (NCEZID), Division of Vector-Borne Diseases (DVBD), “Plague: Frequently Asked Questions”. [Online]. Available:

[2] World Health Organization, “Plague”. [Online]. Available:

[3] C Demeure, O Dussurget, G Mas Fiol, et al., “Yersinia pestis and plague: an updated view on evolution, virulence determinants, immune subversion, vaccination, and diagnostics”, Genes Immun, vol. 20, num. 5, pp. 357-370, 2019. Available: 10.1038/s41435-019-0065-0

[4] L Mordechai, M Eisenberg, T Newfield, et al., “The Justinianic Plague: An inconsequential pandemic?”, Proc Natl Acad Sci, vol. 116, num. 51, pp. 25546-25554, 2019. Available: 10.1073/pnas.1903797116

[5] P Mackowiak, P Sehdev, “The Origin of Quarantine”, Clinical Infectious Diseases, vol. 35, num. 9, pp. 1071–1072, 2002. Available: 10.1086/344062

All you need to know about waterborne diseases

by Dr. Jaclynn Moskow

Woman scientist takes a water sample from polluted pond.


Waterborne diseases are contracted through exposure to contaminated water including drinking water, water used in food preparation, and swimming water. 

They can be caused by bacteria, viruses, and parasites. Below is a partial list of waterborne disease pathogens, their microbial classification, and their resulting illnesses.

Bacteria, virus, and a parasite icon

Classification Microorganism Disease
Bacterium Campylobacter spp. Campylobacteriosis
Bacterium Escherichia coli E. Coli Diarrhea
Bacterium Legionella pneumophila Legionnaires’ Disease
Bacterium Salmonella enterica Salmonellosis
Bacterium Salmonella typhi Typhoid fever
Bacterium Shigella spp. Shigellosis
Bacterium Vibrio cholerae Cholera
Parasite Cryptosporidium spp. Cryptosporidiosis
Parasite Cyclospora cayetanensis Cyclosporiasis
Parasite Entamoeba histolytica Amoebiasis
Parasite Giardia lamblia Giardiasis
Parasite Naegleria fowleri Primary Amoebic Meningoencephalitis (PAM)
Parasite Schistosoma spp. Schistosomiasis
Virus Adenovirus Adenovirus
Virus Hepatovirus A Hepatitis A
Virus Norovirus Norovirus
Virus Rotavirus Rotavirus



The vast majority of waterborne diseases are contracted by individuals who lack access to safe and sanitized water for drinking and personal hygiene. This problem is pervasive around the globe. 

According to the World Health Organization (WHO), 2.2 billion people do not have access to safe drinking water, which equates to 1 in 3 people on the planet. Additionally, 4.2 billion people lack access to adequate sanitation facilities such as hygienic toilets.[1] This lack of access to safe water and sanitation results in 4  billion cases of waterborne diseases annually and 3.4  million deaths.[2] 

Increasing access to clean water worldwide is the single most critical step we can take to prevent morbidity and mortality from these devastating diseases.

Delivery of humanitarian aid and water by military helicopter


Symptoms of waterborne diseases are primarily gastrointestinal and include fever, nausea, vomiting, and diarrhea. 88% of all deaths that occur as a result of diarrhea can be attributed to these infections.[3]  90% of diarrhea deaths involve children under the age of five years.[4] Children are particularly susceptible to waterborne diseases, in part because their naive immune systems have not yet encountered most pathogens. 

Another group who are at increased risk for contracting waterborne diseases is people that are immunocompromised, including individuals living with HIV/AIDS. Unfortunately, the HIV epidemic has hit hardest in areas where access to clean water is lacking. 

Countries that have reported recent outbreaks of Cholera include Bangladesh, Haiti, The Democratic Republic of the Congo, Ethiopia, Somalia, and Yemen.[5]  The Democratic Republic of the Congo and Haiti have also reported recent outbreaks of Typhoid fever, as have Uganda and Pakistan.[6]



Tourists are at increased risk for contracting waterborne diseases, in part because they lack prior exposure and immunity. To avoid waterborne illnesses when traveling to an area of concern, the Centers for Disease Control and Prevention (CDC) recommends the following[7]:

  •     Eat only foods that are cooked and served hot
  •     Avoid food that has been sitting on a buffet
  •     Eat raw fruits and vegetables only if you have washed them in clean water or peeled them
  •     Only drink beverages from factory-sealed containers
  •     Avoid ice – which may have been prepared from unclean water
  •     Only drink pasteurized milk
  •     Wash hands often with soap and water for 20 seconds, especially after using the bathroom and before eating
  •     If soap and water are not available, use a hand sanitizer that contains at least 60% alcohol
  •     Keep your hands away from your face and mouth

Travelers can also receive vaccines for some waterborne diseases, namely, Typhoid Fever, Hepatitis A, and Cholera.  Since the efficacy of these vaccines varies, general precautions including avoidance of tap water should still be taken.

Glass of contaminated water on grey background



Sporadic outbreaks of several waterborne diseases are also reported in industrialized countries. A well-known example occurred in 1993 in Milwaukee, Wisconsin when over a two-week period approximately 403,000 individuals experienced a diarrheal illness. The cause was determined to be Cryptosporidium that had contaminated one of the city’s water-treatment plants.[8]  A more recent example occurred in 2019 when over 2000 residents of a small island in Norway became ill as a result of Campylobacter contaminating the local water supply.[9] 

In 2015, 31% of students at a school camp in South Korea became ill as a result of water contaminated with E. coli.[10] There have also been outbreaks of typhoid fever in the United States. Outbreaks of waterborne disease increase after extreme weather events such as flooding caused by heavy rains and snowfall. After Hurricane Katrina, Salmonella enterica, Vibrio cholerae, and Norovirus were detected in individuals in evacuee camps.[11]



Waterborne diseases can also be contracted by swimming in pools, lakes, rivers, and oceans. This includes Giardia lamblia, which is one of the most common intestinal parasites worldwide, including in the United States. Giardia lamblia can enter the body in a number of ways, including ingestion of water while swimming. 

Another parasite that can be contracted while swimming is Naegleria fowleri, which is found in freshwater and often referred to in headlines as “the brain-eating amoeba.” Naegleria fowleri invades the body via the nose and travels to the brain by way of the olfactory nerve. Unlike Giardiasis, Primary Amebic Meningoencephalitis caused by Naegleria fowleri is almost always fatal. Fortunately, the condition is exceedingly rare.

Over 250 million persons suffer from Schistosomiasis – in Africa, Asia, and the Americas.  Parasites enter through the skin, usually while swimming, working, or simply walking through freshwater. The parasites travel through the bloodstream, eventually lodging in the liver, urinary system, and other organs with resultant damage to tissues, or even cancer which can develop over many years.

Recreational water areas such as pools, hot tubs, and spas are also at risk of contamination by a variety of pathogens. Between 2000 and 2014, 212 reported outbreaks of Cryptosporidium were associated with recreational water facilities.[12] Adenovirus is also known to cause outbreaks from recreational water, as is Legionella pneumophila. Legionella pneumophila is a unique waterborne pathogen in that it often must be aerosolized to cause infection. The organism is transmitted via hot tubs, showers, humidifiers, and air conditioning systems. Aerosolization allows Legionella pneumophila to enter the lungs and thus, unlike other waterborne pathogens, it can cause respiratory illness. A milder form of the disease caused by Legionella species is known as Pontiac fever, and the more severe form is known as Legionnaires’ Disease.



Fortunately, you cannot contract COVID-19 through contaminated water. Viruses may be classified as either enveloped or non-enveloped. Viruses with envelopes have an outer layer of proteins and lipids that surround their viral capsids. Non-enveloped viruses can survive for relatively long periods outside the body – and in much harsher conditions – than can enveloped viruses. 

Viruses that cause waterborne diseases, such as Hepatovirus A, Norovirus, Rotavirus, and Adenovirus, are all non-enveloped. In contrast, members of the Coronaviridae (such as SARS-CoV-2) are enveloped and thus cannot be spread through the water supply.


SARS-CoV-2 structure. Anatomy of the coronavirus


Although we cannot contract SARS-CoV-2 from the water supply, inactive SARS-CoV-2 viral material can still be detected in the wastewater from areas with COVID-19 outbreaks. This can be useful in tracking outbreaks. In Switzerland, for example, laboratories were able to determine that a new “British variant” of SARS-CoV-2 had arrived by simply monitoring wastewater.[13]  In fact, monitoring wastewater is an emerging epidemiological tool for tracking many pathogens, including many of the waterborne diseases discussed above.


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[1] World Health Organization. 1 in 3 people globally do not have access to safe drinking water – UNICEF, WHO. New York, Geneva: World Health Organization; 18 June 2019. [cited 2021 Jan 10]. Available from:

[2] World Bank. World Development Indicators 2015. Washington, DC: World Bank Publications; 2015. [cited 2021 Jan 10]. Available from:

[3] Prüss-Üstün A, et al. Safer water, better health: costs, benefits and sustainability of interventions to protect and promote health. World Health Organization. 2008.

[4] Jong-wook, L. Water, sanitation and hygiene links to health. Geneva: World Health Organization; Nov 2004. [cited 2021 Jan 10.] Available from:

[5] European Centre for Disease Prevention and Control. Cholera worldwide overview. Solna: ECDC; 2021. [cited 2021 Jan 11.] Available from:

[6] World Health Organization. Emergencies preparedness, response – Typhoid fever. New York, Geneva: World Health Organization; 2021. [cited 2021 Jan 11]. Available from:

[7] Center for Disease Control and Prevention. Travels Health – Disease Directory – Typhoid Fever. Atlanta: CDC; 01 Dec 2020. [cited 2021 Jan 10.] Available from:

[8] Mac Kenzie WR, et al. A massive outbreak of Cryptosporidium infection transmitted through the public water supply. N Engl J Med. 1994;331:161-167.

[9] Paruch L, et al. DNA-based faecal source tracking of contaminated drinking water causing a large Campylobacter outbreak in Norway 2019. Int J Hyg Environ Health. 2020 Mar;224:113420.

[10] Park J, et al. A waterborne outbreak of multiple diarrhoeagenic Escherichia coli infections associated with drinking water at a school camp. Int J Infect Dis. 2018

[11] Center for Disease Control and Prevention. Infectious Disease and Dermatologic Conditions in Evacuees and Rescue Workers After Hurricane Katrina – Multiple States, August – September, 2005. Morbidity and Mortality Weekly Report. 30 September, 2005;54(38):961-964.

[12] Hlavsa MC, et al. Outbreaks Associated with Treated Recreational Water – United States, 2000-2014. MMWR Morb Mortal Wkly Rep 2018;67:547–551

[13] Jahn, K. Detection of SARS-CoV-2 variants in Switzerland by genomic analysis of wastewater samples. medRxiv 2021.01.08.21249379; doi:

Strengthen Your Immune System! Your Guide to The Ultimate 2021 New Year’s Resolution

by Dr. Jaclynn Moskow

Infographic detailing various ways to boost immune system


Optimizing your immune system has perhaps never felt as critical as it does going into 2021. In 2020, we saw the emergence of the novel pathogen SARS-CoV-2, and the spread of its resulting disease, COVID-19. While this virus is novel, your immune system is anything but. In fact, your immune system has evolved over millions of years into an extremely complex and intricate network of cells and molecules that keep you alive on a daily basis. And, fortunately, there are steps you can take to help it function to the best of its ability.

Immune System Basics

All immunity can be broken down into two categories: innate and adaptive. Innate immunity is your body’s first line of defense. It involves a variety of cells that perform a variety of functions. These include ciliated respiratory epithelial cells that can physically push pathogens away, macrophages that engage in phagocytosis to engulf pathogens, granulocytic types of phagocytes such as neutrophils and basophils that secrete enzymes to destroy pathogens, and a type of lymphocyte known as the natural killer cell.[1] When innate immunity is unsuccessful at clearing a pathogen, it signals adaptive immunity to assist in the process. Adaptive immunity involves the activation of T and B lymphocytes, cells designed with the capacity to target pathogens in a manner specific to the pathogen at hand.

Illustration of immune system cells
Immune system cells that protect the human body against pathogens


The Immune Response to SARS-CoV-2

When an individual comes into contact with SARS-CoV-2, their innate immune system will first attempt to clear the infection. One reason that SARS-CoV-2 is so infectious is that it has some unique features that make it especially good at evading innate immunity.[2] As a result of this, in many cases, the body will subsequently depend on adaptive immunity to fight the virus. During the adaptive immune response, T cells will help directly destroy cells infected with SARS-CoV-2 and will also stimulate B cells to produce antibodies to the virus and to virally infected cells.


The Importance of Vitamin D

Having sufficient levels of Vitamin D is critical to the function of the immune system and seems to be especially crucial in the case of fighting SARS-CoV-2. Cells involved in both the innate and adaptive immune response have been found to have receptors for Vitamin D, and the presence of Vitamin D enhances their function.[3] It has been noted the there is a correlation between Vitamin D levels and the severity of COVID-19 illness, namely that those who are deficient experience increased hospitalizations and increased mortality.[4] Vitamin D can be acquired from exposure to sunlight or UV lamps, as well as through diet and supplementation. It is estimated that around half the US population has insufficient levels of Vitamin D, although this can be easily addressed.


Why Sleep Matters

Sleep deprivation compromises the immune response while getting a sufficient amount of sleep enhances the immune response. Sleep deprivation is associated with a decreased number of lymphocytes and an increased susceptibility to several infections.[5] It has also been discovered that during sleep, T cells are better able to bind to their targets as a result of adhesion molecules, known as integrins, maintaining a “stickier” state.[6] According to the Center for Disease Control, one in three Americans are getting an inadequate amount of sleep.

Thumbs up illustrating healthy food and thumbs down with unhealthy food icons within

How Diet Plays a Role

The diet we consume is essential to providing our immune system with the micronutrients needed to function properly. Perhaps the most well known of these micronutrients is Vitamin C, which is known to accumulate in phagocytic cells such as macrophages and neutrophils and enhance their ability to destroy infected cells via increasing chemotaxis, phagocytosis, and generation of reactive oxygen species.[7] 

Zinc is another micronutrient that is essential to proper immune function. Almost all immune cells involved in both adaptive and innate immunity show decreased function after Zinc depletion.[8] It is also important to get adequate amounts of Selenium from the diet, as immune cells use Selenium for a number of functions including protection from free radicals that are produced during the inflammatory response.[9] 

Iron is another crucial micronutrient, as it is required for immune cell proliferation and maturation.[10] Iron, Selenium, and Zinc can all be obtained by eating animal products such as beef, chicken, fish, and eggs. The foods with the highest Vitamin C content are fruits and vegetables. Of course, all of these micronutrients can also be obtained via supplementation.


The Significance of Exercise

Any discussion of strengthening immune function would be incomplete without mentioning exercise. Moderate-intensity physical exercise enhances the function of macrophages and increases the circulation of lymphocytes, anti-inflammatory cytokines, and even antibodies. Exercise also stimulates the exchange of immune cells between the circulatory system and tissues.[11] Intense exercise is not needed for this immunoprotective effect. One study found that individuals who walked a minimum of 20 minutes a day for a minimum of 5 days a week, had a 43% reduction in days with symptoms of respiratory infection when compared to those who exercised once a week or less.[12] Other studies have reported similar findings.


The Influence of Chronic Stress

Existing in a state of chronic stress is detrimental to the function of the immune system. Chronically stressed individuals have chronically elevated levels of cortisol and chronically elevated levels of cortisol are associated with a decrease in the number of lymphocytes. Many studies have shown that individuals who report being in a state of chronic stress are more susceptible to respiratory infections. In one of these studies, participants were given nasal drops containing rhinovirus and then quarantined and monitored. Those who were experiencing chronic stress were twice as likely to proceed to develop symptoms of rhinovirus, even after other factors such as age and BMI were accounted for.[13]


Vaccination As a Tool

Vaccines can assist in the body’s ability to fight infection by triggering an immune response to a pathogen that leads to the production of antibodies to that pathogen. These antibodies can then persist for years in the vaccinated individual and often prevent future infection. 

At the time of writing, the FDA has authorized the emergency use of two vaccines designed to protect against SARS-CoV-2 infection. These vaccines are the first vaccines to ever use mRNA as the means of triggering immunity. Both of these vaccines contain pieces of mRNA that encode a portion of SARS-CoV-2’s spike protein. When the body comes into contact with this mRNA, it translates it to create this piece of the spike protein. The immune system then recognizes the protein as foreign and antibodies are created against it.

m-RNA vaccination covid-19, schematic representation

It is worth noting that there have been studies that have shown that adequate levels of Vitamin D enhance the efficacy of various vaccines[14], that ample sleep does the same[15], and that proper nutrition and exercise also boost the likelihood of a vaccine being effective[16] [17].


Stay Healthy in 2021

We can’t change the fact that SARS-CoV-2 has emerged, but we can focus on optimizing our immune health and thereby decrease our chances of suffering a serious illness. By getting adequate sleep, achieving appropriate levels of Vitamin D, Vitamin C, Zinc, Selenium, and Iron, partaking in moderate exercise, and minimizing chronic stress, we aid our immune cells in functioning to the best of their abilities. Taking these steps also helps protect against many other infectious diseases. So, make the commitment today to prioritize your immune health and best wishes for a happy and healthy New Year!


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[1] Gasteiger G, et al. Cellular Innate Immunity: An Old Game with New Players. J Innate Immun 2017;9:111-125.

[2] Taefehshokr N, et al. Covid-19: Perspectives on Innate Immune Evasion. Front Immunol 2020; 11:2549.

[3] Azrielant S, Shoenfeld Y. Vitamin D, and the Immune System. Isr Med Assoc J. 2017 Aug;19(8):510-511.

[4] Pereira M, et al. Vitamin D deficiency aggravates COVID-19: systematic review and meta-analysis. Crit Rev Food Sci Nutr. 2020.

[5] Besedovsky L, Lange T, Haack M. The Sleep-Immune Crosstalk in Health and Disease. Physiol Rev. 2019 Jul 1;99(3):1325-1380.

[6] Dimitrov S, et al. Gαs-coupled receptor signaling and sleep regulate integrin activation of human antigen-specific T cells. J Exp Med. 2019 Mar 4;216(3):517-526.

[7] Carr AC, Maggini S. Vitamin C and Immune Function. Nutrients. 2017 Nov 3;9(11):1211.

[8] Ibs KH, Rink L. Zinc-altered immune function. J Nutr. 2003 May;133(5 Suppl 1):1452S-6S.

[9] Hoffmann PR, Berry MJ. The influence of selenium on immune responses. Mol Nutr Food Res. 2008 Nov;52(11):1273-80.

[10] Soyano A, Gómez M. Participación del hierro en la inmunidad y su relación con las infecciones [Role of iron in immunity and its relation with infections]. Arch Latinoam Nutr. 1999 Sep;49(3 Suppl 2):40S-46S.

[11] da Silveira MP, et al. Physical exercise as a tool to help the immune system against COVID-19: an integrative review of the current literature. Clin Exp Med. 2020 Jul 29:1–14.

[12] Nieman DC, et al. Upper respiratory tract infection is reduced in physically fit and active adults. Br J Sports Med. 2011 Sep;45(12):987-92.

[13] Cohen S, et al. Chronic stress, glucocorticoid receptor resistance, inflammation, and disease risk. Proc Natl Acad Sci U S A. 2012 Apr 17;109(16):5995-9.

[14] Sadarangani SP, Whitaker JA, Poland GA. “Let there be light”: the role of vitamin D in the immune response to vaccines. Expert Rev Vaccines. 2015;14(11):1427-40.

[15] Lange T, et al. Sleep after vaccination boosts immunological memory. J Immunol 187: 283–290, 2011.

[16] Hoest C, et al; MAL-ED Network Investigators. Evaluating associations between vaccine response and malnutrition, gut function, and enteric infections in the MAL-ED cohort study: methods and challenges. Clin Infect Dis. 2014 Nov 1;59 Suppl 4(Suppl 4):S273-9.

[17] Edwards KM, Booy R. Effects of exercise on vaccine-induced immune responses. Hum Vaccin Immunother. 2013 Apr;9(4):907-10.

National Picnic Month and how to enjoy it amid COVID-19

Young friends having barbecue picnic in the nature, playing guitar, playing badminton, enjoying sunny July month outdoors

Did you know July is National Picnic Month? It was a pleasant surprise for us too! 

Summer picnics are a fantastic way to spend time with the family, enjoying beautiful parks and weather – but as we all know this year is different. Unfortunately, COVID-19 is still very a much threat to much of the country, but don’t you worry, we’ve put together our top 5 helpful tips for staying safe while still making the most of your local recreational spaces. So before you pack that hamper, take a few minutes to learn how you can stay safe and be prepared.

1. Keep it outside

This might seem an odd piece of advice for a picnic, but you can never guarantee the weather, so if your picnic gets rained off you may be tempted to take the family indoors.

Bars, restaurants, cafes, and halls make it extremely difficult to socially distance and even in the case where special arrangements have been made by the establishment, close interaction with staff or other patrons is almost unavoidable. Couple this with recirculated air, or worse no ventilation at all, it is a prime area for spreading diseases through contact or inhalation.

Dr. Stephen Berger advises opting for a table outside when dining out, or a spot that is “large, open, and ventilated.”

2. Respect your personal space

It’s hard to imagine spending time with friends and family without sharing a hug, throwing a ball around, or shaking hands. Just think about the number of times you’d normally be in close or direct contact with family friends – sharing food, passing out plates or napkins, handing out drinks; you simply can’t take that risk in the present climate. Respect your own social space and that of others and avoid direct contact with anyone outside your household, even if you know and trust them. Symptoms can take weeks to manifest if they do at all, so remain cautious while out and about or hosting visitors. And remind your kids to not run off too far and to be careful with what they touch.

3. Location, Location, Location!

With certain areas, cities being more greatly affected than others at the moment, check the situation in your area and use your best judgment. Those most at risk, the elderly, and suffers from chronic diseases, the safest option is remaining at home and making the most of any personal gardens.

This may seem cruel when you may not have had the opportunity to see family and friends for a long while and open, clean air and spaces seem the perfect place to reconnect, but please seriously consider your own situation and that of your surrounding areas – the price could prove severe.

4. Don’t forget your face mask

Even though picnics are mostly about food and drink, please take your face mask with you. It can be awkward when eating and drinking, but nonetheless protects you significantly when walking through crowded areas – of course, keep your distance as much as possible as well.

One way to make wearing a mask more fun is to decorate your mask for the occasion, and could be a great way to encourage the kids to keep the masks on! Avoid using paints or anything that will drastically affect the absorbency of your mask – felt tips or chalks should be perfect – or pin on decorations!

5. Keep it clean

The safest way to approach anything you didn’t bring with you is to consider it is dirty or even contaminated, and either wipe it clean before you use it or immediately wash your hands after using it. This may seem extreme, but you cannot see any traces of a virus left behind from someone else and anyone could have a virus without showing symptoms, so it is better to be safe than sorry. You have the benefit of controlling what you bring on a picnic, so make sure you have enough of what you need, so you can dine and play worry-free. Be prepared for longer queues as well, especially toilets.

Hopefully, the weather holds in your area and you do get to head outside for some well-earned relaxation, snacking in your local park and we are certain that by following these tips, and your own best judgment, you will still be able to have a fun and relaxing day and we certainly hope you do!

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How to safely visit loved ones during COVID-19

Family wearing face masksSince COVID-19 arrived, there has been a constant stream of concern and curiosity about how to safely visit loved ones during the pandemic. Can I give them a hug? Should we enjoy a meal together? Are my elderly grandparents off-limits? 

GIDEON Founder, Dr. Stephen Berger, shares with Livestrong what to consider before planning an in-person visit with family and friends. 

First, it is important to acknowledge that keeping yourself safe is just as important as keeping those whom you are visiting safe.   

Secondly, realize that not everyone has obvious symptoms who may be carrying the virus. “It is possible to be an asymptomatic carrier of COVID-19,” Dr. Berger told Livestrong.

Ideally, both you and those you are going to be with would isolate for 14 days prior to your get-together—especially if you each have already ventured outside your home. 

Make sure to have a frank talk with friends and family beforehand about any symptoms experienced or previous exposure to the virus, and do not feel guilty about rescheduling if there are any concerns. 

Dr. Berger also reminds us that the Centers for Disease Control and Prevention (CDC) states those who are over 65 years and who have underlying health issues should avoid group gatherings altogether. He says the risks far outweigh the benefits of a visit. 

Some tips to help best protect you and your loved ones as you make plans to meet include:

  • Keep gatherings to a limited number of people.
  • Select somewhere outdoors, preferably a private setting like a backyard, where you can maintain a safe social distance of six feet apart. 
  • If meeting somewhere in public, try to keep touching of any objects or surfaces to a minimum, then avoid touching your face, and disinfect hands immediately afterward.  
  • Also, while in public, avoid using restrooms as much as possible. 

Dr. Berger also says to be sure and wear a mask, but remember that even masks have limitations because “extremely small particles, including the virus itself, might pass through the spaces that allow air to pass.” Evidence suggests that is essential to adhere to a combination of multiple, safe practices (mask-wearing, handwashing, social-distancing, etc.) to protect yourselves and loved ones from spreading the virus to each another. 

You can read the entire article in Livestrong here.

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Independence Day: 5 tips to stay healthy and safe

Independence day

Independence Day is a time for celebration, family reunions, good food, good drink and momentarily escaping the everyday. The 4th of July has been one of the biggest national holidays since 1776 and draws millions across the country to gatherings for fairs, fireworks, and fun. The significant difference this year is the lingering threat of the coronavirus. How can you and your family still enjoy the day and limit the risk of bringing home more than just fond memories?

Here are our top 5 tips for staying safe this Independence Day:

1. Don’t get locked up

While we highly recommend keeping your enjoyment legal, in this case, we mean avoiding enclosed space wherever possible. Bars, restaurants, cafes, and halls make it extremely difficult to socially distance and even in the case where special arrangements have been made by the establishment, close interaction with staff or other patrons is almost unavoidable. Couple this with recirculated air, or no ventilation at all, and it becomes a prime area for spreading diseases through contact or inhalation.

Only dine or drink at establishments with suitable outdoor spaces, or takeaway and enjoy at your own safe space.

2. Keep your distance

It’s hard to imagine spending time with friends and family without sharing a hug, a dance, or shaking hands. Just think about the number of people you would typically brush up against during a house party or concerts – don’t take that risk in the present climate. Respect your own social space and that of others and avoid direct contact with anyone outside of your household, even if you know and trust them (symptoms can take weeks to show).

3. Check the situation in your location

With certain areas being more greatly affected by COVID-19 than others,  check the situation in your area, and use your best judgment. For those most at risk, the elderly and sufferers from chronic diseases, the safest option is remaining at home and celebrating privately. This might sound like harsh advice, especially as the Independence Day seems like the perfect moment to reconnect with family and friends, but please take it into consideration – the price could prove severe.

4. Make it a Masquerade

If you do decide to venture out to celebrate then please take your face mask with you. It can be awkward when eating and drinking, but nonetheless protects you significantly when walking through crowded areas – of course, keep your distance as well.

One way to make wearing a mask more fun is to decorate your mask for the occasion, and could be a great way to encourage the kids to keep the masks on! Avoid using paints or anything that will drastically affect the absorbency of your mask – felt tips or chalks should be perfect – or pin on decorations!

5. Keep it clean

The safest way to approach anything you didn’t bring with you is to consider it is dirty or even contaminated, and either wipe it clean before you use it or immediately wash your hands after using it. This may seem extreme, but you cannot see any traces of a virus left behind from someone else so it is better to be safe than sorry. If you plan to eat and drink while attending an event bring your own cups, wipes, and even cutlery so you can dine worry-free. Be prepared for longer queues than normal, especially toilets.

Follow these tips, user your best judgment, and have a fun and relaxing 4th of July! fireworks

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