Hepatitis A Clinical Information

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On this page:
Epidemiology of hepatitis A
Communicability of hepatitis A
Recommendations: suspect cases
Lab testing encouraged
Post-exposure prophylaxis recommendations
Immune globulin (IG) 
Vaccination recommendations

Epidemiology of hepatitis A

The clinical course of hepatitis A varies greatly. Symptoms (listed below) typically have an abrupt onset. The likelihood of having symptoms with hepatitis A infection is related to a person's age. In children less than 6 years of age, most (70 percent) hepatitis A infections are asymptomatic. Among older children and adults, infection is usually symptomatic, with jaundice occurring in more than 70 percent of cases.

Communicability of hepatitis A

Hepatitis A virus is transmitted primarily by the fecal-oral route. Persons with hepatitis A are infectious from approximately 2 weeks before symptom onset to up to 2 weeks after symptoms begin.

Recommendations: Suspect cases

• Symptoms of hepatitis A include acute onset of any of the following: fatigue, anorexia, nausea with or without vomiting, abdominal pain, dark urine, fever, headache, diarrhea, or jaundice.
• Hepatitis A cannot be differentiated from other hepatitides on symptoms alone. Laboratory confirmation is needed when diagnosing hepatitis A.
• The incubation period for hepatitis A is usually 4 to 6 weeks (28 to 42 days) after exposure but can range from 2 to 7 weeks (15 to 50 days).
• Suspect cases of hepatitis A are reportable to the Minnesota Department of Health (MDH) at 651-201-5414 or 1-877-676-5414 (toll-free).

Lab testing encouraged for symptomatic persons only

Hepatitis A infection is confirmed by the presence of hepatitis A-specific IgM antibody. Hepatitis A IgM antibody testing and liver function tests should be performed on suspect cases. Testing is not indicated for exposed persons who do not exhibit symptoms.

Post-exposure prophylaxis recommendations

1. Persons exposed within the past 2 weeks should receive post-exposure treatment in accordance with new ACIP recommendations:
   • For healthy persons age 12 months and older, hepatitis A vaccine at the age-appropriate dose is preferred. (Persons who receive a first dose of vaccine as post-exposure prophylaxis should receive a second dose at least 6 months later to confer ongoing protection.)
   • For persons age 40 years and older, in addition to hepatitis A vaccine, immune globulin (IG) may be administered depending on the providers' risk assessment.
   • For immunocompromised persons, persons with diagnosed chronic liver disease, and persons for whom vaccine is contraindicated, IG should be used.
2. Persons exposed more than 2 weeks ago may develop symptoms within the next few weeks, regardless of whether they received treatment for a more recent exposure. The incubation period for hepatitis A is generally about one month but may be 2 to 7 weeks.

Immune globulin (IG)

Get information on where to obtain IG from CDC's Sources for IG and HBIG.

Vaccination recommendations

Hepatitis A vaccine is available for persons age 12 months and older. The vaccine series consists of 2 doses given 6 months apart. The vaccine is recommended for routine vaccination of all children 12 months of age and older, certain high-risk groups (e.g., international travelers), as well as anyone desiring protection against hepatitis A. Hepatitis A vaccine should be administered for infants age 6-11 months traveling outside the United States when protection against hepatitis A is recommended.