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.
• Assess immunity status of patients at every visit and vaccinate according to CDC recommended immunization schedule, health conditions, occupations, and other risk factors, including travel. Document vaccinations administered in the Washington State Immunization Information System.
• Hepatitis A vaccine should be offered to anyone who wishes to reduce their risk of infection. Identification of risk factors are not required.
• Report suspected and confirmed HAV cases to Public Health at (206) 296-4774.