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March 6, 2019

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  • Be aware of an increase in locally-acquired cases of hepatitis A virus (HAV) infection among men who have sex with men (MSM).

  • Consider HAV infection in patients with compatible symptoms including:
    • Fatigue, fever, headache, joint pain, nausea, vomiting, abdominal pain, loss of appetite, dark urine, clay-colored stools, and jaundice.
    • 70% of older children and adults develop symptoms including jaundice; 70% of infections in children <6 years of age are asymptomatic.

  • Collect specimens for laboratory testing on patients with suspected HAV infection:
    • Serum for hepatitis A IgM and liver enzymes (including ALT, AST).
    • Consider testing for hepatitis B (HBsAg and IgM) and hepatitis C (antibody/EIA) virus infections.

  • Ask patients about risk factors, including sexual history, travel history, homelessness or unstable housing, drug use (injection and non-injection), contact with other ill persons, and obtain information about potentially exposed household members and other contacts.

  • Educate patients with HAV infection that they are contagious (fecal-oral route) for 2 weeks before through 1 week after the onset of jaundice, and possibly longer if they have persistent diarrhea.

  • HAV postexposure prophylaxis (PEP) regimens vary by age and health status, see link below. Public Health is available for consultation on when PEP is indicated.

  • Offer and/or recommend HAV vaccine to persons at increased risk, including MSM, and educate MSM patients regarding risk for HAV infection. See the attached fact sheet.

Report confirmed and suspected HAV cases to Public Health at 206-296-4774.

Since November 2018, 6 potentially locally-acquired cases of confirmed HAV infection have been reported. Five cases are MSM and one case reported non-injection drug use. Molecular testing indicates 2 of the cases have identical strains of HAV. No common links have been identified for the cases at this time; investigation is in process. Although none of these cases report connections to persons experiencing homelessness, outbreaks throughout the U.S. continue among persons experiencing homelessness, persons who use drugs, and MSM.

HAV vaccination is recommended for MSM, persons who use drugs (injection and non-injection), and persons experiencing homelessness. Vaccination rates among MSM remain low, even though 10% of new cases nationally occur among MSM. Transmission can occur from any sexual activity with an infected person and is not limited to fecal-oral contact. Measures typically used to prevent transmission of other STDs do not prevent hepatitis A transmission.