Hepatitis A is an inflammation (irritation and swelling) of the liver caused by the hepatitis A virus.

Hepatitis A is transmitted by contaminated food or water, or contact with a person who is currently ill with the disease. The hepatitis A virus is shed in the stools of an infected person during the incubation period of 15 to 45 days before symptoms occur and during the first week of illness. Blood and other bodily secretions may also be infectious.

The virus does not remain in the body after the infection has resolved, and there is no carrier state (a person or animal that spreads the disease to others but does not become ill).

The symptoms associated with hepatitis A are similar to the flu, but the skin and eyes may become yellow (jaundiced). This is because the liver is not able to filter bilirubin from the blood. There are approximately 100,000 total infections in the U.S. every year.

Risk factors include living in a nursing home or rehabilitation center, having a family member who recently had hepatitis A, intravenous drug use, and recent travel to -- or immigration from -- Asia, or South or Central America.

Other common hepatitis virus infections include hepatitis B and hepatitis C, but hepatitis A is the least serious and most mild of these diseases. Both of the others may become chronic illnesses, but hepatitis A does not.

• Jaundice
• Fatigue
• Loss of appetite
• Nausea and vomiting
• Low-grade fever
• Pale or clay-colored stools
• Dark urine
• Generalized itching

The doctor will perform a physical examination and may discover that you have an enlarged and tender liver.

Hepatitis serology tests may show:

• IgM and IgG antibodies to hepatitis A (IgM is usually positive before IgG)
• Elevated liver enzymes (liver function tests)

There is no specific treatment for hepatitis A. Rest is recommended during the acute phase of the disease when the symptoms are most severe. People with acute hepatitis should avoid alcohol and any substances that are toxic to the liver, including acetaminophen (Tylenol).

Fatty foods may cause vomiting, because secretions from the liver are needed to digest fats. Fatty foods are best avoided during the acute phase.

Over 85% of people with hepatitis A recover within 3 months, and over 99% of people recover by 6 months.

The fatality rate is estimated at 0.1%, usually among the elderly and patients with chronic liver disease.

Hepatitis A infection does not become a chronic.

There are usually no complications. One in a thousand cases become fulminant hepatitis, which can be life threatening.

Call for an appointment with your health care provider if symptoms indicate you may have hepatitis A.

Transmission of the virus can be reduced by avoiding unclean food and water, thorough hand-washing after using the restroom, and thorough cleansing if there is any contact with an affected person's blood, feces, or any other bodily fluid.

Daycare facilities and other institutions involving close contact with people may be more susceptible to rapid transmission of hepatitis A. Thorough hand-washing before and after each diaper change, before serving food, and after using the restroom may help prevent institutional outbreaks.

Immune globulin should be given to people in close contact with people with hepatitis A.

Vaccines that protect against hepatitis A infection are available. The vaccine begins to protect 4 weeks after receiving the first dose; the 6- to 12-month booster is required for long-term protection.

People who should consider vaccination include:

• Those traveling to areas or countries with high levels of hepatitis A (those who travel to high-risk areas less than 4 weeks after receiving the initial vaccine may need to receive another preventive medication called immune serum globulin, which is given at the same time as the vaccine but injected at a different site)
• Those who have anal sex
• Intravenous (IV) drug users
• Those with chronic hepatitis B or C infection