Acute hepatitis A is inflammation of the liver that is caused by the hepatitis A virus and that lasts less than 6 months.
Hepatitis A is usually spread when people ingest something that has been contaminated by the stool of an infected person.
Hepatitis A causes typical symptoms of viral hepatitis (including loss of appetite, a general feeling of illness, and jaundice) in older children and adults but may cause no symptoms in young children.
Doctors diagnose hepatitis A based on blood tests.
Vaccination against hepatitis A is recommended for all children and for adults likely to be exposed to the infection or to develop severe complications of the infection.
There is no specific treatment for hepatitis A, but most people recover completely.
(See also Overview of Hepatitis and Overview of Acute Viral Hepatitis.)
Hepatitis A is the most common cause of acute viral hepatitis. It is particularly common among children and young adults. Hepatitis A does not become chronic. That is, the infection does not last longer than 6 months. When people are exposed to the hepatitis A virus, their immune system produces antibodies that protect people from getting hepatitis A again (they are immune to the virus).
In the United States in 2018, over 12,400 cases of hepatitis A were reported, and an estimated 24,900 cases of hepatitis A occurred (many cases are not recognized or not reported). Worldwide, an estimated 1.4 million cases of hepatitis A occur each year.
Transmission of hepatitis A
Hepatitis A is usually spread when people ingest the virus after touching an object or consuming food or drinks that are contaminated by the stool of an infected person (called the fecal-oral route). Spread usually occurs because of poor hygiene—for example, when an infected person prepares food with unwashed hands. Shellfish taken from waters where raw sewage drains are sometimes contaminated and can cause infection when they are eaten raw.
Hepatitis A is sometimes spread in day care centers, where caregivers and children can come in contact with infected stool in diapers.
People can spread the virus before they develop symptoms—before they know they are infected.
Epidemics, usually linked to contamination of water supplies by stool, are common, especially in developing countries.
Hepatitis A does not become a chronic infection. After acute hepatitis resolves, people can no longer transmit the virus to others.
Symptoms of Hepatitis A
Most older children and adults with hepatitis A have typical symptoms of acute hepatitis. These symptoms include
Loss of appetite
A general feeling of illness (malaise)
Vomiting
Pain in the upper right part of the abdomen (where the liver is located)
Dark-colored urine
Jaundice (yellowing of the skin and the whites of the eyes) in about 70%
About 70% of children under 6 years old have no symptoms, and those that have symptoms rarely have jaundice.
Symptoms of cholestasis (a reduction or stoppage of bile flow)—such as pale stools and overall itchiness—may develop.
Symptoms usually disappear after about 2 months but may continue or recur for up to 6 months.
Hepatitis A does not cause severe scarring of the liver (cirrhosis). Hepatitis A rarely becomes severe (fulminant). Such cases are rarer than with hepatitis B.
Recovery from the acute hepatitis A is usually complete.
Diagnosis of Hepatitis A
Blood tests
Doctors suspect hepatitis A in people who have been exposed to the hepatitis A virus and who have typical symptoms, such as jaundice.
Testing usually begins with blood tests to determine how well the liver is functioning and whether it is damaged (liver tests). Liver tests involve measuring the levels of liver enzymes and other substances produced by the liver.
If tests detect liver abnormalities, other blood tests are usually done to check for hepatitis virus infection. These blood tests can identify parts of specific viruses (antigens), specific antibodies produced by the body to fight the virus, and sometimes genetic material (RNA or DNA) of viruses.
Prevention of Hepatitis A
Using good hygiene when handling food can help prevent the spread of hepatitis A. People should wash their hands with soap and water after using the bathroom, after changing a diaper, and before handling food.
Avoiding contaminated water supplies is also important. People need to be particularly careful when they travel to areas where sanitation may be inadequate.
Vaccination against hepatitis A is recommended for all children (see figure Routine Vaccinations for Infants, Children, and Adolescents). It is also recommended for adults at high risk of exposure to hepatitis A:
Travelers to parts of the world where hepatitis A is widespread
People who work in diagnostic or research laboratories that handle hepatitis A virus
People with chronic liver disorders or bleeding disorders
Men who have sex with men
People who use illicit drugs (who are often infected for reasons other than drug use)
People who do not have stable housing or who are homeless
People who anticipate close contact with an adopted child during the first 60 days after the child arrives in the United States from an area where hepatitis A is common
Pregnant women who are at risk of getting hepatitis A infection during pregnancy
People with chronic liver disorders (including chronic hepatitis C) should be vaccinated against hepatitis A because they may have an increased risk of developing fulminant hepatitis and liver failure due to the hepatitis A virus.
Prevention after exposure to hepatitis A
Preventive measures are recommended for family members and close contacts of people with hepatitis A because they have been exposed to the infection (called postexposure prophylaxis).
If people who have not been previously vaccinated are exposed to hepatitis A, they are given one of the following:
Healthy people aged 1 to 40 years: One dose of the hepatitis A vaccine
People who are over 40 or who have a weakened immune system or chronic liver disease: Standard immune globulin
Standard immune globulin is a preparation containing antibodies obtained from the blood of people with a normal immune system. This treatment prevents or decreases the severity of infection.
Treatment of Hepatitis A
General measures
There is no specific treatment for hepatitis A.
People with hepatitis A should not drink alcohol because it can damage the liver further. There is no need to avoid certain foods or limit activity.
Most people can safely return to work after jaundice resolves.
More Information
The following is an English-language resource that may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
Centers for Disease Control and Prevention: Hepatitis A: This web site provides links to an overview of hepatitis A, including statistics, transmission, symptoms, diagnosis, treatment, and prevention, as well as links to information for health care practitioners. Accessed May 19, 2022.
