Hepatitis A is a liver disease caused by the hepatitis A virus. Hepatitis A can affect anyone, and is still a common disease in the United States. Good personal hygiene and proper sanitation can help prevent hepatitis A.
Vaccines are also available for long-term prevention of hepatitis A virus infection in persons 2 years of age and older. Immune globulin is available for short-term prevention of hepatitis A virus infection in all ages.
Frequently Asked Questions
How common is hepatitis A virus (HAV) infection in the United States?
In 2009, 1,987 acute symptomatic cases of hepatitis A were reported; the incidence was 1.0/100,000, the lowest rate ever recorded. After adjusting for asymptomatic infection and underreporting, the estimated number of new infections was 21,000.
How is HAV transmitted?
- Person-to-person transmission through the fecal-oral route (i.e., ingestion of something that has been contaminated with the feces of an infected person) is the primary means of HAV transmission in the United States. Most infections result from close personal contact with an infected household member or sex partner.
- Common-source outbreaks and sporadic cases also can occur from exposure to fecally contaminated food or water. Uncooked HAV-contaminated foods have been recognized as a source of outbreaks. Cooked foods also can transmit HAV if the temperature during food preparation is inadequate to kill the virus or if food is contaminated after cooking, as occurs in outbreaks associated with infected food handlers. Waterborne outbreaks are infrequent in developed countries with well-maintained sanitation and water supplies.
Who is at increased risk for acquiring HAV infection?
What are the signs and symptoms of HAV infection?
Some persons, particularly young children, are asymptomatic. When symptoms are present, they usually occur abruptly and can include the following:
- Loss of appetite
- Abdominal pain
- Dark urine
- Clay-colored bowel movements
- Joint pain
In children aged <6 years, 70% of infections are asymptomatic; if illness does occur, it is typically not accompanied by jaundice. Among older children and adults, infection is typically symptomatic, with jaundice occurring in >70% of patients.
When symptoms occur, how long do they usually last?
Symptoms usually last less than 2 months, although 10%–15% of symptomatic persons have prolonged or relapsing disease for up to 6 months.
What is the incubation period for hepatitis A?
The average incubation period for hepatitis A is 28 days (range: 15–50 days).
How long does HAV survive outside the body? How can the virus be killed?
HAV can live outside the body for months, depending on the environmental conditions. The virus is killed by heating to 185 degrees F (85 degrees C) for one minute. However, the virus can still be spread from cooked food if it is contaminated after cooking. Adequate chlorination of water, as recommended in the United States, kills HAV that enters the water supply.
Can hepatitis A become chronic?
No. Hepatitis A does not become chronic.
Can persons become reinfected with HAV after recovering from hepatitis A?
No. IgG antibodies to HAV, which appear early in the course of infection, provide lifelong protection against the disease.
How is HAV infection prevented?
Vaccination with the full, two-dose series of hepatitis A vaccine is the best way to prevent HAV infection. Hepatitis A vaccine has been licensed in the United States for use in persons 12 months of age and older. The vaccine is recommended for persons who are more likely to get HAV infection or are more likely to get seriously ill if they get hepatitis A. (See "Who should be vaccinated against hepatitis A?")
Immune globulin is available for short-term protection (approximately 3 months) against hepatitis A, both pre- and post-exposure. Immune globulin must be administered within 2 weeks after exposure for maximum protection.
Good hygiene — including handwashing or use of hand sanitizer after using the bathroom, changing diapers, and before preparing or eating food — is also integral to hepatitis A prevention, given that the virus is transmitted through the fecal–oral route.
For more information on vaccination for hepatitis A contact the ADPH Immunization Division.