Hepatitis A virus

Pronunciation

HEH-puh-TY-tis ... VY-rus

Hepatitis A virus

Summary

• Hepatitis A virus is a virus that causes a serious liver disease.
• It is usually spread by contact with an infected person’s stool by eating food he or she has handled after not washing hands, but it can be spread in other ways.
• Symptoms of infection include jaundice, dark urine, and fever and other flu-like symptoms.

Hepatitis

Definition

• Hepatitis means inflammation of the liver.
• When the liver is inflamed or damaged, its function can be affected.
• Heavy alcohol use, toxins, some medications, and certain medical conditions can cause hepatitis, but it is often caused by a virus.
• In the United States, the most common hepatitis viruses are hepatitis A virus, hepatitis B virus, and hepatitis C virus.
• Hepatitis A is a highly contagious, short-term liver infection caused by the hepatitis A virus.
• People who get hepatitis A may feel sick for a few weeks to several months but usually recover completely and do not have lasting liver damage. In rare cases, hepatitis A can cause liver failure and even death; this is more common in older people and in people with other serious health issues, such as chronic liver disease.

Incidence

• In 2018, there were an estimated 24,900 hepatitis A cases were reported in the United States.
• Because some people don’t ever get diagnosed, the actual number of cases reported in that year is probably closer to 24,900.
• Since 2016, person-to-person outbreaks of hepatitis A have been occurring across the United States mainly among people who use injection drugs or are experiencing homelessness, resulting in more than 32,000 cases.

Risk factors

• International travelers
• Men who have sex with men
• People who use injection or non-injection drugs (all those who use illegal 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 human immunodeficiency virus infection
• For more information about assessing risk for hepatitis A, refer to Table 3 in Prevention of Hepatitis A Virus Infection in the United States: Recommendations of the Advisory Committee on Immunization Practices, 2020.

Signs and symptoms

Among older children and adults, infection is typically symptomatic. Symptoms usually occur abruptly and can include the following:

• Fever
• Fatigue
• Loss of appetite
• Nausea
• Vomiting
• Abdominal pain
• Dark urine
• Diarrhea
• Clay-colored stool
• Joint pain
• Jaundice

Most (70%) of infections in children younger than age 6 are not accompanied by symptoms. When symptoms are present, young children typically do not have jaundice; most (>70%) older children and adults with HAV infection have this symptom.

Incubation period

• Symptoms of hepatitis A usually last less than 2 months, although 10%–15% of symptomatic persons have prolonged or relapsing disease for up to 6 months (9–13).
• The average incubation period for HAV is 28 days and ranges between 15–50 days.

Diagnosis

Diagnosis is with a combination of history, physical examination including travel and food history, symptoms, ordering a blood tests for hepatitis A.

Treatment

• To treat the symptoms of hepatitis A, rest, adequate nutrition, fluids and other supportive measures are recommended.
• Some people with severe symptoms will need medical care in a hospital.

Vaccination

• Vaccination with the full, two-dose series of hepatitis A vaccine is the best way to prevent infection.
• Hepatitis A vaccine has been licensed in the United States for use in people 1 year of age and older.

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 hepatitis A

People at increased risk for severe disease from hepatitis A infection

Other people recommended for vaccination

• Pregnant women at risk for hepatitis A or risk for severe outcome from hepatitis A infection
• Any person who requests vaccination
• How is the hepatitis A vaccine given?
• There are two types of hepatitis A vaccine.

Vaccination schedule

• The first type, the single-dose hepatitis A vaccine, is given as two shots, 6 months apart, and both shots are needed for long-term protection against hepatitis A.
• The other type is a combination vaccine that protects people against both hepatitis A and hepatitis B.
• The combination vaccine can be given to anyone 18 years of age and older and is given as three shots over 6 months.
• All three shots are needed for long-term protection for both hepatitis A and hepatitis B.

Immunoglobulins

• Immune globulin can provide short-term protection against hepatitis A, both pre- and postexposure.
• Immune globulin must be administered within 2 weeks after exposure for maximum protection.
• Given that the virus is transmitted through the fecal-oral route, good hand hygiene—including handwashing after using the bathroom, changing diapers, and before preparing or eating food—is integral to hepatitis A prevention.

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