Massachusetts General Hospital

Hepatitis A

What is hepatitis?

The liver is one of the organs that helps with digestion, but is not part of the digestive tract. It is the largest organ in the body and carries out many important functions, such as making bile, changing food into energy, and cleaning alcohol and poisons from the blood.

Hepatitis is inflammation of the liver that sometimes causes permanent damage. It is caused by viruses, bacteria, certain medications, or alcohol. It may also be caused by certain diseases, such as autoimmune diseases, metabolic diseases, and congenital (present at birth) abnormalities, such as biliary atresia and Wilson disease. Generally, symptoms of hepatitis include fever, jaundice (yellowing of the skin and eyes), and an enlarged liver. There are several types of hepatitis.

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What is hepatitis A?

Hepatitis A is a highly contagious and sometimes serious liver disease caused by the hepatitis A virus. Once called infectious hepatitis, today it is more commonly known as hepatitis A.

Hepatitis A does not result in chronic infection, but complete recovery from hepatitis A can be slow. In adult patients with hepatitis A, the illness may last for at least one month, with recovery taking up to six months. Hepatitis A rates in the United States have declined by 92 percent since the vaccine (hepatitis A) first became available in 1995.

What are the symptoms of hepatitis A?

The following are the most common symptoms of hepatitis A. However, each individual may experience symptoms differently. Symptoms of hepatitis A often resemble flu-like symptoms. Symptoms may include:

• Fever

• Chills

• Joint pain

• Fatigue

• General feeling of weakness

• Loss of appetite

• Nausea

• Vomiting

• Abdominal discomfort

• Dark urine

• Clay-colored stools

• Jaundice--yellowing of the skin and eyes

• Diarrhea

In some adults and in most children, especially those younger than 6 years of age, there are often no symptoms. The symptoms of hepatitis A may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.

What causes hepatitis A?

This type of hepatitis is usually spread by fecal-oral contact or fecal-infected food and water, and may also be spread by blood-borne infection (which is rare). The following is a list of modes of transmission for hepatitis A:

• Consuming food made by someone who touched infected feces

• Drinking water that is contaminated by infected feces (a problem in developing countries with poor sewage removal)

• Touching an infected person's feces, which may occur with poor hand washing (outbreaks may occur in large child-care centers, especially when there are children in diapers) 

• Sexual contact with an infected person

Generally, casual contact in school or the workplace does not cause spread of the virus.

What are the risk factors for hepatitis A?

Children, teens, and adults who may be at high risk of hepatitis A include the following:

• People traveling to areas of where hepatitis A is prevalent, including, but not limited to: Africa, Asia (except Japan), the Mediterranean basin, Eastern Europe, the Middle East, Central and South America, Mexico, and parts of the Caribbean

• People living in or relocating to any community in the U.S. or abroad with one or more recorded hepatitis A outbreaks within the past five years

• Military personnel

• People who engage in high-risk sexual activity

• Users of illegal intravenous (IV) drugs

• Hemophiliacs and other recipients of therapeutic blood products

• Employees of day-care centers

• Institutional care workers

• Laboratory workers who handle live hepatitis A virus

• People who handle primate animals that may be carrying the hepatitis A virus

Hepatitis A is sometimes called a traveler's disease because it is the most frequently occurring, vaccine-preventable infection in travelers. However, it is possible to become infected with hepatitis A virus without ever leaving the United States. Some cases reported in the United States have occurred in people with no identifiable risk factors.

Prevention of hepatitis A

In addition to avoiding risky behaviors, there are two methods for prevention of hepatitis A:

• Immune globulin. A preparation of antibodies that is given both before anticipated exposure to the hepatitis A virus and soon after exposure.

• Hepatitis A vaccine. The vaccine consists of killed hepatitis A virus that stimulates the body's natural immune system. After the vaccine is given, the body makes antibodies that protect a person against the virus. Please consult your doctor if you have any questions about its use.

The CDC recommends the hepatitis A vaccine for the following groups who are at risk for the infection, as well as for anyone who wants to have the vaccine:

• People traveling to or working in countries that have high or intermediate rates of hepatitis A

• All children 12 months of age

• Men who have sex with men

• Illegal drug users

• People at occupational risk for the disease

• People with chronic liver disease

• People with clotting-factor disorders such as hemophilia

How is hepatitis A diagnosed?

In addition to a complete medical history and physical examination, a blood test called IgM anti-HAV is needed to diagnose hepatitis A. This test looks specifically for the presence of antibodies against the hepatitis A virus in the blood. 

Treatment for hepatitis A

Specific treatment for hepatitis A will be determined by your doctor based on:

• Your age, overall health, and medical history

• Extent of the disease

• Your tolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

Most people recover from hepatitis A infection without medical intervention; however, bed rest and some medications may be suggested.