Questions & Answers

What causes hepatitis A?
Hepatitis A is a liver disease caused by hepatitis A virus (HAV).

How does hepatitis A virus spread?
Hepatitis A virus is spread from person to person by putting something in the mouth that has been contaminated with the stool of a person infected with hepatitis A virus. This type of spread is called "fecal-oral." This can happen in a variety of ways, such as when an infected person who prepares or handles food doesn't wash his or her hands adequately after using the toilet and then touches other people's food. A person can also be infected by drinking water contaminated with hepatitis A or drinking beverages chilled with contaminated ice. Contaminated food, water, and ice can be significant sources of infection for travelers to many areas of the world. For this reason, the virus is more easily spread in areas where there are poor sanitary conditions or where good personal hygiene is not observed.

Most hepatitis A viral infections in the United States result from international travel, contact with a household member or sex partner who has hepatitis A, or illegal drug use. Casual contact, as in the office, factory, or school setting, does not spread the virus.

Can hepatitis A be spread through sex?
Yes. Sex involves close, intimate contact (vaginal, anal, or oral sex) and increases the risk of exposure to hepatitis A virus in the feces of an infected person.

What are the symptoms of hepatitis A?
People with hepatitis A can feel quite sick. If symptoms are present, they usually occur suddenly and can include fever, tiredness, loss of appetite, nausea, abdominal discomfort, dark urine, and jaundice (yellowing of the skin and eyes).

How long does it take to show signs of illness after coming in close contact with a person who has hepatitis A viral infection?
It can take 15–50 days to develop symptoms (average 28 days). People with hepatitis A infection might not have any signs or symptoms of the disease. Adults are more likely to have symptoms than children. About 7 out of 10 adults have symptoms, while children less than age 6 years usually have no symptoms. In some people, symptoms of hepatitis A recur in 6–9 months; this condition is called relapsing hepatitis A.

How long do symptoms last?
Symptoms usually last less than 2 months; however, a few people are ill for as long as 6 months.

How serious is hepatitis A?
Hepatitis A can be quite serious. Among reported cases of hepatitis A (CDC, 2007 data), 35% required hospitalization, with people age 60 and older more likely to be hospitalized. Many days of work are missed due to hepatitis A, as well. Certain people, such as people with chronic hepatitis C, can get very sick and die from hepatitis A. Death from hepatitis A is fairly rare in healthy young people but more common in people age 60 years and older.

Can people become chronically infected with hepatitis A virus?
No. Hepatitis A only causes acute (recently acquired) infection, not chronic infection. Relapsing hepatitis A, as described above, goes away and is NOT a chronic infection. (Both hepatitis B and hepatitis C viruses can cause chronic infection.)

How common is hepatitis A in the United States?
In 2008, there were 2,585 acute cases of hepatitis A reported to the Centers for Disease Control and Prevention (CDC) and an estimated 22,000 new infections. The occurrence of hepatitis A virus infection has been steadily decreasing over the past several years. Since the licensure of vaccines to prevent infection with hepatitis A virus, disease rates have fallen to the lowest level ever recorded in the United States.

How common is hepatitis A infection throughout the world?
This infection occurs widely throughout the world. It is especially common in countries in Latin America, Africa, the Middle East, Asia, the Caribbean, and the Western Pacific. This means that people can become infected with the virus in many travel destinations, even when using luxury tourist accommodations.

The only destinations around the world for which CDC does not recommend hepatitis A vaccination or immune globulin (IG) for U.S. travelers before departure are Canada, Western Europe, Australia, New Zealand, and Japan.

How does a person know if he or she is infected with hepatitis A?
To diagnose acute hepatitis A, a blood test called "IgM class antibody to hepatitis A virus" (IgM anti- HAV) is needed. There is also a blood test available that shows if a person was infected with hepatitis A virus in the past (total hepatitis A antibody [called anti-HAV]). Talk to your doctor or someone from your local health department if you suspect that you have been exposed to the virus or any type of hepatitis virus.

Is there a medicine to treat hepatitis A?
No. There is no medicine that will treat or "cure" hepatitis A. Supportive care includes bed rest, fluids, and fever-reducing medicines. Take fever-reducing medicine only if your physician recommends it.

How long can a person with hepatitis A virus infection spread the virus?
The most likely time for an infected person to spread hepatitis A virus to others is during the two weeks before the infected person develops symptoms (e.g., yellowing of skin and eyes). Clearly, if a person does not even know that they are infected, it makes it difficult to protect others from getting the infection. The risk of spreading hepatitis A virus becomes smaller over time and can still be present one week or longer after symptoms develop. Infants are more likely to spread hepatitis A virus for longer periods of time.

If an unvaccinated person has had close personal contact with a person who is infected with hepatitis A, what should the person do?
If an unvaccinated person thinks that he or she might have been exposed to the hepatitis A virus, that person should call their healthcare professional immediately to schedule an appointment right away to determine whether a real exposure has occurred and whether IG and/or hepatitis A vaccine should be administered. IG is a concentrated dose of human antibodies that includes anti-HAV. In most cases, either of these preparations can protect an exposed person from developing hepatitis A viral infection. It's important to give IG within two weeks followingan exposure. Hepatitis A vaccine should be given as soon as possible after an exposure (the closer to the exposure the better). (See the questions below for more information about IG and hepatitis A vaccine and in which situations vaccine and/or IG is the best choice).

Can a person get infected with hepatitis A virus more than once?
No. Once you recover from the infection, you develop hepatitis A antibodies (called anti-HAV) that provide life-long protection from future infections. After recovering from hepatitis A, you won't get it again and you cannot transmit the hepatitis A virus to others.

How does hepatitis A differ from hepatitis B virus (HBV) and hepatitis C virus (HCV)?

• Hepatitis A, B, and C are three different viruses that attack and injure the liver and cause similar symptoms in people with acute (recently acquired) disease.
• Hepatitis A virus is spread by getting viral infected fecal matter into a person's mouth who has never had hepatitis A virus infection (e.g., an infected person who doesn't wash his or her hands after using the bathroom and then handles food for public consumption or an infected person who has sex with a person who has never had hepatitis A). Hepatitis B and hepatitis C viruses are spread when an infected person's blood or blood-contaminated body fluids enter another person's bloodstream.
• Hepatitis B and hepatitis C virus infections can cause lifelong (chronic) liver problems. Infection with hepatitis A virus does not.
• There are vaccines that will protect people from infection with hepatitis A and hepatitis B. Currently, there is no vaccine to protect people from hepatitis C virus infection.
• There are medications that are approved by the Food and Drug Administration (FDA) for treatment of chronic hepatitis B and chronic hepatitis C viral infections.
• If a person has had one type of viral hepatitis in the past, it is still possible to get the other types.

Questions and answers about hepatitis A vaccine

Technical content reviewed by the Centers for Disease Control and Prevention, March 2011