Hepatitis A spreads through the fecal-oral route, meaning the virus enters your body when you ingest something contaminated with fecal matter from an infected person. Even microscopic amounts of the virus are enough to cause infection. The most common paths are close contact with someone who’s infected and consuming contaminated food or water.
How the Fecal-Oral Route Works
The hepatitis A virus (HAV) replicates in the liver and gets excreted through bile into the stool at very high concentrations. When an infected person doesn’t wash their hands thoroughly after using the bathroom, the virus can transfer to surfaces, food, drinks, or other people. Once you swallow the virus, it travels through your gastrointestinal tract, reaches the liver, and begins replicating there, starting the cycle over again.
This makes hepatitis A fundamentally different from hepatitis B and C, which spread through blood and bodily fluids. Hepatitis A is all about contamination through the digestive system.
Person-to-Person Contact
Direct contact with an infected person is the leading cause of hepatitis A transmission, particularly in the United States. This includes household contact, sexual contact (especially oral-anal contact), and sharing drugs or drug equipment. Since 2016, outbreaks across multiple U.S. states have been driven primarily by person-to-person spread, hitting three groups especially hard: people who use drugs, people experiencing homelessness, and men who have sex with men.
What makes person-to-person spread so effective is that infected people are most contagious one to two weeks before they show any symptoms. During this window, virus concentrations in the stool and blood are at their peak. Someone can be spreading the virus to close contacts for weeks without knowing they’re sick. Once jaundice or other symptoms appear and the body starts producing antibodies, contagiousness drops quickly. One important exception: infants and young children can shed the virus for up to six months after infection, often without ever showing obvious symptoms themselves.
Contaminated Food and Water
Foodborne hepatitis A is less common in the U.S. than person-to-person spread, but it drives outbreaks worldwide. The FDA identifies water, shellfish, raw vegetables, fruit (particularly berries), and salads as the most frequently cited food sources. Shellfish are a classic risk because filter-feeding species like oysters and mussels concentrate the virus from contaminated water in their tissues. Raw produce can pick up the virus through contaminated irrigation water or handling by an infected worker.
Contaminated drinking water is a major source in countries with limited sanitation infrastructure. Travelers to regions with high rates of hepatitis A face elevated risk, particularly in parts of Central and South America, Africa, the Middle East, and South and Southeast Asia. Even ice cubes made from tap water or salads rinsed in local water can be enough.
Why the Virus Is Hard to Kill
Hepatitis A is a remarkably tough virus, which helps explain why it spreads so easily. Standard alcohol-based hand sanitizers are largely ineffective against it. Research published in the Journal of Hospital Infection found that ethanol at concentrations of 80% or even 95% was not sufficiently effective against HAV, even with two full minutes of contact time. A gel with 54% ethanol showed zero effect whatsoever. Adding acids like phosphoric acid to alcohol formulations improved performance against many viruses, but HAV remained resistant even to some of these enhanced products.
This means soap and water is your best defense for hand hygiene when hepatitis A is a concern. The mechanical action of scrubbing with soap physically removes the virus in a way that chemical sanitizers cannot reliably achieve. Cooking food to high temperatures does inactivate the virus, which is why raw and undercooked foods carry the greatest risk.
The Contagiousness Timeline
The average incubation period for hepatitis A is 28 days, with a range of 15 to 50 days. That’s a long gap between swallowing the virus and feeling sick, and the most dangerous part of this timeline is the pre-symptomatic window. An infected person is shedding the highest concentration of virus one to two weeks before symptoms start. By the time they develop the telltale signs of hepatitis A (fatigue, nausea, abdominal pain, dark urine, jaundice), their contagiousness is already dropping rapidly.
This pre-symptomatic shedding is what makes outbreaks difficult to contain. A food worker who’s infected, for instance, could be preparing meals for hundreds of people during their most contagious period without any idea they’re carrying the virus.
Recent Outbreaks Show Ongoing Risk
Hepatitis A hasn’t gone away. A large outbreak across central Europe illustrates how quickly the virus spreads when conditions allow. Between January and May 2025, four countries reported a combined 2,097 cases. Slovakia, where the outbreak began in late 2022, saw 880 cases in that five-month period alone. Czechia confirmed 600 cases with six deaths, mostly in young children. Hungary reported 530 cases, primarily among adults, and Austria recorded 87 cases with three deaths.
These numbers are a reminder that hepatitis A remains a serious public health threat, particularly in communities with lower vaccination rates or gaps in sanitation.
How to Protect Yourself
Vaccination is the most reliable protection. The hepatitis A vaccine is part of the routine childhood immunization schedule, typically given starting at age one. If you weren’t vaccinated as a child, you can get the vaccine at any age, and it’s especially important before traveling to higher-risk regions.
Beyond vaccination, practical prevention comes down to hygiene and food safety. Wash your hands thoroughly with soap and water after using the bathroom, after changing diapers, and before preparing or eating food. When traveling in areas with limited sanitation, stick to bottled or boiled water, avoid ice, and eat food that’s been cooked and served hot. Peel fruits yourself rather than eating them pre-cut. Skip raw shellfish if you’re unsure of the water source. And remember: hand sanitizer is not a substitute for handwashing when it comes to this particular virus.