Hepatitis A, a liver disease caused by hepatitis A virus (HAV), is highly contagious. Historically, it was called infectious hepatitis. HAV attacks the liver, but unlike hepatitis B and C, it does not cause chronic infection, liver cancer or chronic liver failure. Each year, approximately 1.5 million people worldwide become infected with hepatitis A and there were an estimated 180,000 cases in the U.S. in 1999. It is most prevalent in areas of poor sanitation and hygiene, and was common in the United States until 1950s. Children in developing countries are infected at a very early age, usually without symptoms. In the developed world, more and more people do not contract the disease during childhood due to the good sanitation. They therefore are at risk when adults from the more severe form of the disease which they might catch when they travel to areas of the world where hepatitis A is common. Most individuals recover from acute infection with Hepatitis A. However, a few adults will require hospitalization and treatment and some may progress to need liver transplantation.Children tend to do well with this virus generally complaining of flu-like symptoms. While most adults do well, some may not and will require medical assistance.
Symptoms: The infection may go unnoticed especially in children under 6 years old. In older children or adults, most develop an illness about a month after the infection. In those who develop symptomatic hepatitis A, flu-like symptoms, such as fever, chills, and a general feeling of weakness, may occur. Other symptoms may include anorexia, nausea, jaundice (yellowing of the eyes and skin), dark urine, light-colored stools, abdominal pain, and fatigue. Symptoms usually last less than 2 months; a few persons are ill for several months and may require hospitalization. The average incubation period for hepatitis A is 28 days (range: 15-50 days).
Diagnosis: A blood test (IgM anti-HAV) is needed to diagnose hepatitis A. Antibody to IgG infers immunity to the hepatitis A virus.
Cause: Hepatitis A is found in the stool of persons with hepatitis A. The virus is usually spread through person-to-person contact or through contaminated food and water. Rarely, it spreads through contact with infected blood.
People at risk include: international travelers; people living in areas where hepatitis A outbreaks are common (Southeast Asia, Mexico, South and Central America, the Caribbean and Africa); people who live with or have sex with an infected person; sexually active gay men; injection drug users; hemophiliacs; during outbreaks, day care children and employees; and laboratory workers working directly with the virus.
Food and water borne outbreaks also occur frequently and although almost any food can be implicated the most common sources are:
- Shellfish from sewage-polluted water eaten raw or poorly cooked.
- Foods handled without sufficient hygiene and not cooked subsequently.
Casual contact, as in the usual office, factory, or school setting, does not spread the virus. Common areas of hepatitis A virus outbreaks include the Gulf Coast states, and restaurants that serve shell fish. One famous outbreak in the late 1990s involved produce from Mexico that was not adequately cleansed before transportation to the United States. Over 200 adult individuals developed acute hepatitis A.
Prevention and Vaccination: Avoid tap water when traveling internationally and practice good hygiene and sanitation.
Two products used to prevent hepatitis A virus infection are Immune globulin and hepatitis A vaccine.
- Immune globulin is a preparation of antibodies that can be given before exposure for short-term protection against hepatitis A and for persons who have already been exposed to hepatitis A virus. Immune globulin must be given within 2 weeks after exposure to hepatitis A virus for maximum protection.
- Hepatitis A vaccine is recommended (before exposure to hepatitis A virus) for persons who are more likely to get hepatitis A virus infection or are more likely to get seriously ill if they do get hepatitis A. Two commercially available and licensed hepatitis A vaccines are Havrix (SmithKline Beecham) and VAQTA (Merck). The recommended vaccine schedule for both vaccines is a primary immunization followed by a second, booster dose 6-12 months later. Neither vaccine is licensed for use in children under age 2.
- Hepatitis A vaccination is required in 17 states within the United States in order to enter the 7th grade.
- The hepatitis A vaccination is available and should be used in all individuals. Any individual at risk: health care workers, travelers, day care workers, parents with children in day care, sexually active individuals, school teachers and food handlers, etc. should receive the hepatitis A vaccine.
Hepatitis delta virus (HDV) is spread through contact with infected blood. This disease occurs only in people who are already infected with hepatitis B. People at risk include anyone infected with hepatitis B. Injection drug users who have hepatitis B have the highest risk. People who have hepatitis B are also at risk if they have sex with a person infected with hepatitis D or if they live with an infected person.
Prevention: Vaccination against hepatitis B for those not already infected; also, avoiding exposure to infected blood, contaminated needles, and an infected person's personal items (toothbrush, razor, nail clippers).
Treatment: Drug treatment with alpha interferon.
Hepatitis E (HEV) is spread through food or water contaminated by feces from an infected person. This disease is uncommon in the United States. People at risk include international travelers; people living in areas where hepatitis E outbreaks are common; and people who live or have sex with an infected person. It is most common in pregnant women.
Prevention: There is no vaccine for hepatitis E. The only way to prevent the disease is to reduce the risk of exposure to the virus. This means avoiding tap water when traveling internationally and practicing good hygiene and sanitation.
Treatment: Hepatitis E usually resolves on its own over several weeks to months.
All information provided in this site is offered for educational purposes only, and it is not intended nor implied to be a substitute for professional medical advice. Always consult your own physician or healthcare provider with any questions you may have regarding a medical condition.