Hepatitis A Virus
Transmission of the Hepatitis A Virus
The hepatitis A virus is highly contagious and can spread easily from person to person. Transmission most often occurs when susceptible people consume stool from an infected person (known as fecal-oral transmission). This can occur by consuming contaminated water or foods, or touching contaminated surfaces and then placing your hands near or in the mouth (even though they may look clean). The virus cannot be spread from animals to humans.
Following infection with the hepatitis A virus, a person does not immediately become sick. Once the virus enters the body, it travels to the liver, where it begins to multiply. Symptoms usually appear after approximately four weeks. This period between transmission of the virus and the beginning of symptoms is called the hepatitis A incubation period. This can be as short as 15 days or as long as 45 days.
(Click Hepatitis A Transmission for more information. Click Hepatitis A Symptoms for information on possible symptoms of the disease.)
How Common Is an Infection With This Virus?
Infection with the hepatitis A virus is most common in developing countries, where there is overcrowding, poor sanitation, and poor personal hygiene. In developing countries, hepatitis A in adults does not occur very often because of exposure to the hepatitis A virus in childhood.
Hepatitis A outbreaks can still happen in developed countries. This most often occurs in the restaurant setting from poor personal hygiene, from infected food handlers, or in food-processing plants. Outbreaks of hepatitis A are also common in institutions, crowded house projects, prisons, and in military forces in adverse situations.