Hepatitis A: Breaking Out All Over

Carolyn Wester, MD, MPH


May 21, 2019

Editorial Collaboration

Medscape &

Hepatitis A Outbreaks

Multiple states across the country have reported hepatitis A virus (HAV) outbreaks, primarily among people who use drugs, people experiencing homelessness, and men who have sex with men. Since outbreaks of hepatitis A were first identified in 2016, more than 17,000 cases have been reported. More than half of these cases (57%) resulted in hospitalization, a higher rate than typically associated with this infection.[1,2] Severe complications have resulted in higher rates of liver failure, liver transplantation, and deaths—170 of which have occurred nationwide.

HAV is highly transmissible from person to person through the fecal-oral route. The recent number of HAV infections is unprecedented since the adoption of the universal childhood vaccination recommendations in 2006, and has resulted in community outbreaks among populations at risk that have been difficult and costly to control.

Healthcare providers should consider HAV in anyone with jaundice or clinical symptoms that suggest infection (eg, fever, fatigue, anorexia, nausea, vomiting, diarrhea, abdominal pain, or dark urine). If no alternative diagnosis is likely, serologic testing for acute viral hepatitis (including anti-HAV IgM) and liver function tests should be ordered. Do not test people without signs of acute hepatitis; false-positive anti-HAV IgM results can occur in people without acute clinical hepatitis illness. Providers should rapidly report all cases of hepatitis A to the health department to ensure timely case investigation and follow-up of contacts.

Vaccinate at Every Opportunity

The best way to prevent HAV infection is through vaccination. The Centers for Disease Control and Prevention (CDC) urges healthcare providers to assess and vaccinate groups at highest risk of acquiring HAV infection as well as those at risk for serious complications. Historically, vaccine coverage among these at-risk populations has been low.

Healthcare providers should offer hepatitis A vaccination to the following groups:

  • People who use drugs (injection or non-injection)

  • People experiencing unstable housing or homelessness

  • Men who have sex with men

  • People who are currently or were recently incarcerated

  • People with chronic liver disease, including cirrhosis, hepatitis B, or hepatitis C

CDC strongly encourages healthcare providers to administer the hepatitis A vaccine to at-risk patients regardless of the original presenting complaint or the type of clinical facility. Every encounter with the healthcare system represents an opportunity to provide hepatitis A vaccination to people at highest risk.

To stop outbreaks, vaccination against hepatitis A is the top priority. One dose of single-antigen hepatitis A vaccine has been shown to control outbreaks of hepatitis A and provide up to 95% seroprotection in healthy individuals for up to 11 years.[3,4] Prevaccination serologic testing is not required to administer the hepatitis A vaccine. Vaccinations should not be postponed if vaccination history cannot be obtained or records are unavailable. When feasible and reasonable, you can consider the combined hepatitis A and hepatitis B vaccine (TWINRIX) for people in groups recommended for both hepatitis A and B vaccination by the Advisory Committee on Immunization Practices (ACIP), such as men who have sex with men, people who have chronic liver disease, and people who inject drugs. If TWINRIX is administered, completing the series is needed to ensure maximum protection against both hepatitis A and hepatitis B.

Web Resources