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July 25, 2019

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  • Be aware of a second confirmed case of locally acquired hepatitis A virus (HAV) since April 1, 2019 in a King County adult who is living homeless and using injection drugs. Both cases have identical genotype test results according to CDC that have not been seen elsewhere in the United States. Two additional suspected cases of locally acquired HAV infection have been identified recently among persons living homeless and using injection drugs.
  • 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 IgG and liver enzymes (including ALT, AST).
    • Test for hepatitis B (HBsAg and IgM) and hepatitis C (antibody/EIA) to rule out other types of viral hepatitis.
  • Ask patients about risk factors, including homelessness or unstable housing, sexual history, travel history, injection and non-injection drug use, contact with other ill persons, and obtain information about potentially exposed household members and other contacts.
  • Counsel patients with HAV infection about the importance of practicing good hand hygiene – including thoroughly washing hands after using the bathroom, changing diapers, and before preparing or eating food and that they are most contagious (fecal-oral route) for 2 weeks before through 1 week after the onset of jaundice, and possibly longer if they have persistent diarrhea.
  • Suspected or confirmed cases should be excluded from volunteering and working in sensitive areas (food handling, health care, childcare settings), until assessed by Public Health.
  • Patients with suspected or confirmed hepatitis A who are living homeless should be isolated while infectious.
    • Public Health can assist with coordinating housing of patients living homeless with confirmed or suspected hepatitis A who do not require hospitalization.
    • Public Health will also work to identify exposed contacts and facilitate HAV postexposure prophylaxis (PEP).
  • HAV PEP regimens vary by age and health status, see link below. Public Health is available for consultation on when PEP is indicated.
  • Report confirmed and suspected HAV cases to Public Health at 206-296-4774.
To avoid missed opportunities, emergency departments, healthcare systems and clinics should routinely offer HAV vaccine at all clinical encounters to persons at increased risk, including those living homeless and persons who inject drugs, and healthcare providers should counsel patients regarding risk for HAV infection. In addition, HAV vaccine should be offered to anyone who wishes to reduce their risk of infection (See CDC hepatitis A vaccine recommendations, below).

On July 23, 2019, Public Health received laboratory-confirmation of a second locally acquired HAV infection in a King County adult who was living homeless and using injection drugs. PCR-based genetic sequencing at CDC determined that both confirmed HAV cases have an identically matching result that is unique to these two cases. This provides laboratory evidence of transmission within the homeless population here in King County that is unrelated to any other HAV outbreak across the United States.

Two additional suspected cases of HAV among persons living homeless and who inject drugs have been reported. No strain typing is available for these suspect cases; investigations are ongoing.

Multiple states across the country have reported outbreaks of HAV, primarily among persons living homeless and persons who use drugs. Nationally, since 2016, more than 22,000 cases have been reported. Rates of hospitalization are higher than typical for HAV infections, and severe complications have been reported, including liver transplantation or death; at least 216 deaths have occurred nationwide.

HAV can spread easily in communities experiencing homelessness and crowded settings where handwashing facilities are limited and sanitation is poor. Healthcare providers should be vigilant for potential HAV infections among persons who are at increased risk, including persons living homeless, persons who use drugs (injection and non-injection), and men who have sex with men (MSM).

The best way to prevent HAV infection is through vaccination with the hepatitis A vaccine. In February 2019, CDC recommended all persons aged > 1 year experiencing homelessness be routinely immunized against HAV. Primary care providers, acute care facilities, and emergency departments should offer HAV vaccine during clinical encounters to persons at increased risk, including persons living homeless. Pre-vaccination serologic testing is not necessary before administration of hepatitis A vaccine, and vaccinations should not be postponed if vaccine history is unavailable.