Hepatitis A

Hepatitis A is spread through food or water contaminated with the virus or by coming in contact with an infected person. While hepatitis A can cause a severe, acute disease, it does not cause a chronic infection as do some of the other hepatitis viruses. If you are exposed to hepatitis A, your immune system produces antibodies in response to the virus. This test detects hepatitis A antibodies in the blood.

While hepatitis has many different causes, the signs and the symptoms are the same. In hepatitis, the liver is damaged and unable to function normally. It cannot process toxins or waste products such as bilirubin for their removal from the body. During the course of the disease, bilirubin and liver enzyme levels in the blood can increase. While tests such as bilirubin or a liver panel can tell your doctor that you have hepatitis, they will not tell her what is causing it. Antibody tests for hepatitis viruses may help determine the cause.

If you are exposed to hepatitis A, your body will first produce hepatitis A IgM antibodies. These antibodies typically develop 2 to 3 weeks after first being infected and persist for about 2 to 6 months. Hepatitis A IgG antibodies are produced within 1 to 2 weeks of the IgM antibodies and usually persist for life. Because hepatitis A IgM antibodies develop early in the course of infection, a positive hepatitis A IgM test is usually considered diagnostic for acute hepatitis A. A total hepatitis A antibody test detects the presence of the IgM and IgG antibodies and may help determine if you have been infected in the past and have some immunity to the disease. A test for hepatitis A IgM may be part of an acute viral hepatitis panel that may be used to determine which virus is causing symptoms when viral hepatitis is suspected.

A vaccine is available to help prevent hepatitis A. According to the CDC, cases of hepatitis A have dropped by 89% since the introduction of the hepatitis A vaccine in 1995. In 2007, just under 3000 cases of acute hepatitis A were reported, the lowest to date.