Hepatitis A

Hepatitis A virus causes acute liver inflammation and spreads readily in settings with inadequate sanitation or during person-to-person outbreaks among close-contact networks. Unlike hepatitis B or C, it does not cause chronic infection, and most people recover fully within weeks to months. Outbreaks can still strain healthcare systems, particularly among vulnerable populations such as people experiencing homelessness or in areas recovering from natural disasters. Virus Tracker presents available regional signals where open outbreak data exists.

The virus spreads primarily through the fecal-oral route, via contaminated food or water, or close personal contact with an infected person. Outbreaks have been linked to contaminated produce, shellfish, and inadequate sanitation, as well as to person-to-person spread in certain social networks.

Symptoms can include fatigue, nausea, abdominal pain, loss of appetite, and jaundice, though young children often have mild or no symptoms. Illness typically resolves within a few weeks, though recovery can occasionally take longer. Severe liver failure is rare but possible, especially in older adults or people with existing liver disease.

A safe and effective vaccine provides long-term protection and is recommended for children, travelers to endemic areas, and people at higher occupational or behavioral risk. Safe water and food handling, along with good hand hygiene, further reduce transmission risk.

Surveillance relies on case reporting and outbreak investigation, often tracing sources back to specific food items, water supplies, or social networks. Vaccination coverage tracking helps identify communities at higher risk of outbreaks.

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