Hepatitis A virus is a common infectious cause of liver disease globally. Most common in areas of Africa, South America, and Asia, it is often considered a travel-related disease. Children often remain symptom-free, while adults can show a range of clinical signs, from a mild flu-like illness to severe liver disease.
Hepatitis A virus is a common cause of foodborne illness globally. It can affect people anywhere, though it is most commonly associated with travel to areas in Africa, Asia, or South America.
Hepatitis A virus remains a common infectious cause of worldwide liver disease.
When foodborne infection arises, hepatitis A virus is commonly attributed to leafy greens or frozen organic berries, such as strawberries.
Children often remain symptom-free, while older individuals may develop anorexia, vomiting, diarrhea, fever, lethargy, GI upset, and belly pain. Some go on to develop signs of liver disease, including yellow eyes or skin.
Hepatitis A virus can easily be prevented with a single vaccination dose for those at higher risk of illness, including those who travel and those with occupational exposures.
Transmission occurs via the fecal-oral route. Treatment is symptomatic, as there is no cure. Often transmitted via organic frozen berries or leafy green veggies, human-human contact, and less commonly, contaminated water, outbreaks can effectively be controlled with vaccination. Hand cleanliness and safe food handling are also important for illness prevention.
Hepatitis A virus: the ins and outs
Hepatitis A virus (HAV), often thought of as a travel-associated illness, most commonly in Africa, South America, or Asia, can occur anywhere in the world. The disease, caused by a Picornaviridae virus, is a leading cause of liver inflammation (hepatitis) globally.
From 2015 through October 6, 2023, the Centers for Disease Control and Prevention (CDC) reported that HAV outbreaks in the U.S. affected 37 states, with 44,915 people known infected and 27,445 (61%) hospitalizations. Over 420 deaths resulted. Although the disease is often associated with travel to less-developed nations, we still see significant yet preventable cases here in the U.S.
Hepatitis A transmission
HAV is transmitted principally via the fecal-oral route. This means that fecal contamination of fruits, vegetables, and water leads to exposure and potential infection. Improper handwashing after toileting, before food handling, and associated activities further increase the spread risk.
Direct spread from person to person can occur through personal contact, sharing drug paraphernalia, or caring for a sick loved one. HAV is very easily transmitted; people who are infected but not yet symptomatic can shed the virus.
Though uncommon, waterborne outbreaks may occur due to the ingestion of untreated water or water contaminated by sewage.
Common food culprits
Most commonly, the point source (or first person infected in an outbreak in a specific location) becomes infected by eating or drinking something contaminated (fecal) by the virus.
Common foods identified as sources of HAV outbreaks include:
- Leafy greens
Fresh veggies often cause illness, with the virus surviving for decent periods, especially when refrigerated.
Water can also serve as a means of transmission. Direct transmission can occur via poor hygiene and sanitation. Make sure you have 70% or higher alcohol hand sanitizer readily available if handwashing isn’t possible.
Organic may not always be better
Many people want to eat foods without additives, antibiotics, or chemicals. Eating foods with the organic label accomplishes this. While eating organic may seem healthier and more humane, consuming organic products may increase the risk of foodborne illness.
Organic strawberries, a European outbreak, 2018
Frozen organic strawberries imported from Poland were identified as the source of a 2018 HAV outbreak in over 30 people in Sweden and Austria. These strawberries were distributed to wholesalers, food service kitchens, and an ice cream producer. Strawberry ice cream was consumed in eight of the cases in Austria, demonstrating the durability of HAV. Thus, one doesn’t have to consume fresh or frozen fruit alone to become infected.
Organic strawberries, a U.S. outbreak, 2022–2023
A recent HAV outbreak was declared resolved in September 2023. Ten people from California, Washington, Oregon, and Hawaii developed hepatitis between November 24, 2022, and May 27, 2023. No one died, but four out of 10 were hospitalized. The HAV contaminated food source was identified as frozen organic strawberries that originated from several farms and a common supplier located in Baja California, Mexico.
HAV lasts for variable times on surfaces and longer in refrigerated foods. It survives even longer in frozen foods. Further, contamination of soil or sewage can last weeks or longer. HAV lasts several hours on one’s hands. While in water, the virus may survive up to 330 days, depending on the type of water and ambient temperatures.
Hepatitis A risk factors
Those at highest risk for developing infection from HAV include those who:
- Are in close personal contact with an infected person
- Travel internationally
- Have occupational exposure (e.g., food handlers, fruit pickers)
- Use illicit drugs
- Engage in oral-anal sex
- Are experiencing homelessness
- Lack access to safe water
- Lack of proper sewer systems
Hepatitis A symptoms
Symptoms are often self-limiting in most people, meaning they resolve without intervention. Signs may develop within as little as two weeks after exposure but up to two months later (incubation of 14–28 days is most common). The younger one is at the time of infection, the less likely they are to develop clinical signs. Symptoms may include:
- Lethargy (feeling tired)
- Loss of appetite (anorexia)
- Muscle pain (myalgia)
- Joint pain (arthralgia)
- Belly pain (often in the right upper abdomen)
Though not all patients go on to develop liver disease, those who do will also demonstrate varying signs about a week after general symptoms develop. These may include darker than normal urine, pale stools, and yellowing (jaundice) of the skin and the whites of the eyes. Patients who develop liver abnormalities will also have elevated liver enzymes. Usually, signs will resolve within one to six weeks after onset.
Rarely, non-liver changes can develop, including a rash, kidney disease, and inflammation of the lungs, heart muscle, pancreas, or gallbladder.
Complications of HAV
Usually, HAV causes symptoms for weeks to months, with few having long-lasting effects. The liver, the most regenerative organ in our bodies, usually recovers. However, people with prior liver conditions, or HIV, require significant hospitalization, as they can develop liver failure or even pass away.
A rare percentage of people may have a bout of disease, recover, and then relapse before finally returning to good health.
Hepatitis A treatment
Like with many viral diseases, there is no cure for HAV. Treatment is supportive with fluid support, managing comfort, and treating individual clinical signs. If liver failure develops, hospitalization is often required.
In the face of a large-scale outbreak, post-exposure vaccination may be used on those exposed but not yet showing clinical signs. This can help to limit those who develop clinical disease and help to minimize the spread and impact of the disease. In fact, according to the CDC and current research, a single HAV vaccine in exposed individuals has been shown to control outbreaks.
Preventing hepatitis A
As the saying goes, an ounce of prevention is better than a pound of cure. The best practice is to prevent and protect oneself from HAV infection. Steps to lessen risk include:
- Pre-exposure vaccination. Vaccination is the best means of protection against HAV. It can protect those traveling to high-risk areas, farmworkers, food handlers, or others at higher risk.
- Post-exposure vaccination. When administered within two weeks of exposure to HAV, a single immunization effectively prevents clinical disease.
- Work hygiene. Improved and maintained on-farm hygiene and sanitation practices.
- Personal hygiene. Overall, sound personal hygiene practices, especially pre-meals and post-toileting.
- Avoid handling food when sick. This is best practice regardless of the type of illness.
- Test food. Proper food sampling and testing for at-risk foods.
- Safe drinking water. Chlorination destroys HAV in water.
- Heating foods and liquids. Heating to a minimum of 185°F (85°C) for one minute will kill the virus. The lower the temperature of a surface, food, or water source, the more likely the virus will survive.
Hepatitis A, a preventable illness
HAV, despite its global distribution, is a vaccine-preventable disease. The disease remains common in Africa, Asia, and South America, and travelers to this area should consider pre-exposure vaccination. Proper hand hygiene, food preparation, and water treatment are essential to prevention in endemic regions because disease transmission occurs when feces contaminate food or water. Given that there is no cure and treatment is symptomatic, infection prevention is key.
- Food and Environmental Virology. Persistence of Hepatitis A Virus in Fresh Produce and Production Environments, and the Effect of Disinfection Procedures: A Review.
- StatePearls. Hepatitis A.
- Eurosurveillance. Hepatitis A outbreak linked to imported frozen strawberries by sequencing, Sweden and Austria, June to September 2018.
- Annals of Medicine & Surgery. Organic strawberry- Plausible vehicle of the hepatitis A virus transmission.
- CDC. Outbreaks of hepatitis A across the U.S.