Hepatitis A is an infectious liver disease caused by the hepatitis A virus (HAV). The disease varies in clinical severity from a mild illness lasting 1-2 weeks to a severely disabling disease lasting several months.
There are other kinds of viral hepatitis such as hepatitis B, hepatitis C, hepatitis D, and hepatitis E. These diseases and the viruses that cause them are not related to hepatitis A although they also affect the liver. They may have other, different symptoms and different modes of transmission. This means that there are different ways of spreading the disease and different means for preventing and controlling these diseases.
The incubation period (the time between initial contact with the virus and the onset of the disease) for hepatitis A ranges from 15 to 50 days. The length of the incubation period depends on the amount of virus to which a person is exposed. Exposure to a large dose of virus results in a short incubation period.
Three of every four persons infected with hepatitis A virus have symptoms. When symptoms develop they include fever, tiredness, loss of appetite, nausea, abdominal pain, dark urine, and yellowing of the skin and eyeballs (jaundice).
Infected individuals can spread the virus from 2 weeks before the symptoms begin to 2 weeks after symptoms end. However, an infected person who has no symptoms can still spread the virus. Unlike some other forms of viral hepatitis, hepatitis A does not cause long-term (chronic) damage and is usually not fatal. Those with pre-existing liver disease have a higher risk of complications. The severity of the illness tends to increase with age. After infection, most people are immune to HAV for life.
The common test for hepatitis A is the antibody test. When a person becomes infected, the body creates antibodies to protect itself from the virus. There is a blood test available to measure these antibodies. A doctor should also do a complete medical examination and get information about your activities in order to make a clinical diagnosis of hepatitis A.
The hepatitis A virus is found in the feces of infected persons. The virus is usually spread from person to person by putting something in the mouth that has been contaminated with the feces of a person with hepatitis A. The virus is more easily spread under poor sanitary conditions and when good personal hygiene is not practiced. The virus can also be transmitted through oral and anal sexual activity.
People can get hepatitis A by drinking contaminated water or eating raw and undercooked shellfish harvested from contaminated water. Fruits and vegetables or other foods can become contaminated during handling. However, working with an infected person, for example sharing an office, does not pose the risk for hepatitis A.
There continues to be little evidence of risk for hepatitis A infection in the workplace. Health care workers are not considered to be at increased risk when they follow standard infection control procedures. Workers in the food handling sector may be at risk if exposed to contaminated food or water. People who visit, live or work in countries where hepatitis A is common may be at increased risk. As well, people who work with HAV infected animals or in a hepatitis A research laboratory may be at risk.
A report from Quebec shows that sewage workers may be at increased risk during community outbreaks.
In the US some reports state that staff of institutions for disabled children may be at increased risk. However, due to insufficient data, the National Advisory Committee on Immunization (NACI) in Canada has not recommended routine vaccination of such workers.
The reported incidence of HAV in Canada remained above 4 per 100,000 between 1980 and 1997 and has declined to 1.47 per 100,000 in 2004.
The prevention of hepatitis A in the workplace is based on good hygiene and sanitation.
Education programs for workers about personal hygiene practices should emphasize that careful hand washing is extremely important in the prevention of disease. Workers should be informed about using appropriate protective clothing and about removing it at the end of the shift. They should also be informed about the necessity of washing hands frequently, and before eating, drinking, or smoking; they should also avoid nail biting.
A hepatitis A vaccine is available and highly effective in preventing infection. Consult your health professional.
Document last updated on September 1, 2009