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January 12, 2024

Hepatitis A Virus (HAV) infection in encampment with possibility of secondary cases in Tukwila, King County

Actions requested

  • Be aware of one laboratory-confirmed hepatitis A virus (HAV) infection among people seeking asylum and who have been staying in a homeless encampment in Tukwila and temporary housing at a hotel in SeaTac.
    • Secondary cases exposed to this case would be expected between January 1, 2024, and February 28, 2024.
    • This case likely involved an exposure at the encampment to an unknown HAV-infected person in early December 2023.
  • Consider HAV infection in patients with compatible symptoms, especially in patients who are experiencing homelessness or report living in temporary housing, including:
    • Fatigue, headache, fever, malaise, joint pain, nausea, abdominal pain, vomiting, diarrhea, jaundice, clay-colored stool, or dark urine.
    • Clinical jaundice may be a late sign of HAV infection or may never develop, especially in children
      • 70% of older children and adults develop symptoms, including jaundice
      • 70% of infections of children <6 years of age are asymptomatic
    • Patients with HIV or chronic liver disease are at increased risk for severe disease.
  • Conduct diagnostic testing on patients with suspected HAV infection.
    • Serum for HAV IgM and IgG and liver enzyme levels (ALT, AST).
    • A test for total anti-HAV antibody detects immunity from prior immunization or infection, not acute infection.
    • Test for hepatitis B (HBsAg and IgM) and hepatitis C (antibody/EIA) to rule out other types of viral hepatitis.
  • Be familiar with the HAV PEP protocol for susceptible individuals, which is recommended as soon as possible within 2 weeks of exposure and varies by age and health status of the exposed person:
  • Age Group Health Status Hep A vaccine Immune Globulin (IG)**
    <12 months Healthy No 0.1 mL/kg
    12 months – 40 years Healthy 1 dose*** None
    >40 years Healthy 1 dose*** 0.1 mL/kg
    >12 months Immunocompromised or chronic liver disease 1 dose*** 0.1 mL/kg
    >12 months Contraindication to vaccine No 0.1 mL/kg
  • Counsel patients on the following considerations for preventing HAV transmission:
    • Hepatitis A is highly contagious and spread via the fecal-oral route, typically from person-to-person or through consumption of contaminated food and drink.
    • Persons with HAV infection are infectious from 2 weeks prior to symptom onset through one week after the onset of jaundice OR 14 days after symptom onset if no jaundice.
    • Patients should practice diligent hand hygiene practices: washing hands frequently and using soap and warm water to lather for 20 seconds after each bathroom use.
    • Persons with HAV infection should not prepare food for others while symptomatic and while infectious.
    • Persons with HAV infection should not work or attend sensitive settings (including food service, healthcare, and childcare) while symptomatic and infectious.
      • Patients employed in these settings must be cleared by Public Health to return to work.
  • Vaccination with Hepatitis A vaccine is the best way to prevent infection.
  • Report suspected and confirmed HAV cases to Public Health at (206) 296-4774.

Background

Public Health is investigating one laboratory-confirmed case of Hepatitis A (HAV) among people seeking asylum and who are staying at an encampment located in Tukwila, WA, and a hotel in SeaTac. This case was likely exposed to HAV at the encampment. Healthcare providers should be vigilant for potential HAV infections among people who spent time at an encampment in Tukwila or a hotel in SeaTac. Public Health has begun outreach to the encampment and hotel residents and staff to provide education, contact tracing, and vaccination to this community.

Since December 1, 2023, three laboratory-confirmed HAV cases have been identified in King County, including this case. The previous two cases are unrelated to this case and may have involved exposure outside of King County. Both of the previous cases are among people who are stably housed. Public Health may refer patients to outpatient and emergency care services based on symptoms or exposure to HAV for assessment or HAV PEP. Healthcare facilities should be aware of HAV infection control measures to prevent transmission to staff and other patients.

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.

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