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Hepatitis A Basic Information

  • More than 30 states have been affected by hepatitis A outbreaks since 2016.
  • The outbreaks are occurring mostly among people who use drugs and people who are homeless.
  • There is a safe and effective vaccine that prevents hepatitis A; all children aged 12–23 months, as well as all children and adolescents 2–18 years of age who have not previously received hepatitis A vaccine (known as “catch up” vaccination) should be vaccinated.

Topics on this page: What is Hepatitis A? | How Many People Have Hepatitis A ? | Who Is Most Affected? | How Is Hepatitis A Transmitted? | Hepatitis A Prevention | Testing | Treatment | Help Raise Awareness about Hepatitis A Outbreaks | Learn More About Hepatitis A

What Is Hepatitis A?

Hepatitis A is a liver infection caused by the hepatitis A virus (HAV). Hepatitis A can be transmitted when a person ingests the virus from food, drinks, or other objects that have been contaminated by small amounts of stool from an infected person. This can happen through unwashed hands when an infected person prepares food, by close personal contact such as during sex, or caring for someone who is ill. HAV is highly contagious and can range from a mild illness lasting a few weeks to severe illness lasting several months. Unlike hepatitis B and C, HAV infection does not cause long-term, chronic liver disease. Although most people who get hepatitis A are only sick for a few weeks, in rare cases, HAV infection can cause liver failure and death. This is more common in individuals with existing liver disease and other illnesses often seen in homeless persons.

Most children under 6 years of age do not have symptoms when they get hepatitis A. Older children and adults will usually have symptoms. The symptoms will generally clear-up within 2 months of infection and may include:

  • Fatigue
  • Loss of appetite
  • Stomach pain
  • Nausea
  • Jaundice

Once a person becomes infected with HAV, the person develops antibodies that protect them from getting the virus again. The best way to prevent HAV infection is by getting vaccinated.

How Many People Have Hepatitis A?

Since the release of the first vaccine in 1995, the rate of new HAV infections in the United States declined by more than 95% from 1996 to 2011. From 2012 through 2016, the number of hepatitis A cases fluctuated because large foodborne outbreaks occurred. From August 2016 through August 2020, 33 states reported hepatitis A outbreaks spread through person-to-person contact resulting in over 33,000 infections with high numbers of hospitalizations and deaths.

Globally, HAV infection is most common in countries with poor sanitary conditions and hygienic practices and transitional economies according to the World Health Organization .

Who Is Most Affected?

Anyone who has not been vaccinated or previously infected can become infected with HAV. The most common risk factors among people with new HAV infections include: 1) drug use (injection and non-injection); 2) having sex with an infected person; 3) coming in direct contact with persons who have HAV infection; 4) homelessness and 5) traveling to countries where HAV infection is more common.

For countries where HAV infection is common, the risk factors are poor sanitation and lack of clean, safe drinking water.

How Is Hepatitis A Transmitted?

HAV is highly contagious. It is spread primarily when a person ingests the virus from food, drinks, or objects that have been contaminated by small amounts of stool from an infected person; sex with an infected person, particularly if it involves anal-oral contact; and through injection drug use. In crowded, unsanitary conditions, HAV can be spread quickly and cause outbreaks by exposure to contaminated water or food (such as eating raw shellfish from water polluted with sewage).

Hepatitis A Prevention

Hepatitis A is a vaccine-preventable disease. The hepatitis A vaccine is safe and effective and is usually given in two shots, six months apart. The following people should be vaccinated against hepatitis A:

  • Children:
    • All children aged 12–23 months
    • All children and adolescents 2–18 years of age who have not previously received hepatitis A vaccine (known as “catch up” vaccination)
  • People at increased risk for HAV infection:
    • International travelers
    • Men who have sex with men
    • People who use injection or noninjection drugs
    • People with occupational risk for exposure
    • People who anticipate close personal contact with an international adoptee
    • People experiencing homelessness
    • People at increased risk for severe disease from HAV infection
    • People with chronic liver disease
    • People with HIV infection
  • Other people recommended for vaccination:
    • Pregnant women at risk for HAV infection or severe outcome from HAV infection
    • Any person who requests vaccination
  • Vaccination during outbreaks:
    • Unvaccinated people in outbreak settings who are at risk for HAV infection or at risk for severe disease from HAV

The Centers for Disease Control and Prevention (CDC) and the Advisory Committee on Immunization Practices (ACIP) published additional guidance on the hepatitis A vaccine in 2020. Find out if you should get the hepatitis A vaccine and then use the HealthMap Vaccine Finder to help get your hepatitis A vaccine.

Because not all people are vaccinated for hepatitis A, it is important to know that it can also be prevented by maintaining good hygiene and food preparation practices. Hand washing after using the bathroom and before preparing any food along with proper cleaning of surfaces before and after food preparation can help prevent the spread of hepatitis A and other food-borne infections.


Health care providers can diagnose HAV infection through a blood test. The blood test can be ordered based on symptoms and can detect HAV immunoglobulin M antibodies (IgM anti-HAV), which identifies current infection. IgM anti-HAV can be detected in a blood test 5-10 days before symptoms appear but disappear within 6 months after symptoms appear. It is important to get tested soon after symptoms appear to detect infection and prevent further transmission.


There is no specific treatment for hepatitis A. Once a person is infected with HAV, the best way to recover is to rest, drink plenty of fluids, eat a balanced diet, and work with your healthcare provider to manage any nausea. Depending on how severe the infection is, it may take several weeks or even months to fully recover from symptoms of hepatitis A.

Help Raise Awareness About Hepatitis A Outbreaks

Get the latest from CDC about outbreaks in the United States.

Learn More About Hepatitis A

Centers for Disease Control and Prevention, Division of Viral Hepatitis

National Institutes of Health:

Content created by Office of Infectious Disease and HIV/AIDS Policy (OIDP)
Content last reviewed on August 26, 2020