News Flash

Health Alerts

Posted on: December 18, 2019

Health Advisory: Hepatitis A Outbreak in Snohomish County

Actions requested:  

  • Health care providers, particularly hospital emergency departments and urgent care centers, should offer hepatitis A vaccines to all patients who are homeless, users of injection or non-injection illicit drugs, infected with hepatitis B or hepatitis C, or have other liver disease, e.g., alcoholic cirrhosis.
  • Serologic screening for immunity before vaccination is not necessary; however, prior doses of the vaccine may be recorded in the Washington State Immunization Information System (WA IIS).
  • Where feasible and appropriate, use standing orders/order sets to ensure vaccination of the atrisk population.
  • Record vaccine doses administered in your EMR or WA IIS.
  • Ensure all vaccines are stored and handled appropriately. 
  • Hospitals should also: 
    • Offer hepatitis A vaccine to health care personnel who have frequent close contact with patients who are homeless and/or use injection or non-injection illicit drugs. 
    • Ensure appropriate cleaning of restrooms frequented by persons who are homeless and/or use injection or non-injection illicit drugs, using methods similar to those for norovirus.
  • Among suspected cases of hepatitis A (e.g., anorexia, nausea, fatigue, jaundice): 
    • Submit serum for anti-HAV IgM; 
    • Notify the SHD Communicable Disease Program at 425.339.5278 
    • Impose enteric precautions until seven days after onset of jaundice. 
    • Offer hepatitis A vaccine to previously unimmunized close contacts.  


  • Four cases of hepatitis A have been reported in Snohomish County residents during the past week. 
  • All have been experiencing homelessness and/or injecting drugs. 
  • These cases have centered around the Marysville-Tulalip area. 
  • Although molecular confirmation of linkage to the statewide outbreak is pending, the cases’ features are consistent with that profile (i.e., homelessness and/or drug injection). 

Additional information about the vaccine 

  • One dose of single-antigen hepatitis A vaccine provides better protection than one dose of combined hepatitis A/hepatitis B (Twinrix®) vaccine. For this reason, only single-antigen hepatitis A vaccine should be used for post-exposure prophylaxis. 
  • Providers should consider short-term risks of exposure to HAV, the likelihood of follow-up to complete multi-dose immunization and the need for protection from hepatitis B when selecting vaccines for those at risk. Do not delay vaccination to obtain a different formulation of vaccine if Twinrix is not available. 
  • Persons who have been exposed to HAV in the prior 2 weeks who are not known to be immune should receive single-antigen hepatitis A vaccine and/or immune globulin. 
  • Persons injecting drugs who are not known to be immune should also receive a full hepatitis B series. 

Helpful Links 

- Dr. Chris Spitters, Interim Health Officer Snohomish Health District

Facebook Twitter Email

Other News in Health Alerts

Health Advisory: Updated Guidance for Healthcare Providers on Increased Supply of Nirsevimab

Posted on: January 26, 2024 | Last Modified on: September 23, 2022

Health Alert: Ebola Disease Outbreak

Posted on: October 13, 2022

Health Advisory: Acute Flaccid Myelitis

Posted on: October 11, 2022

Update for Clinicians: November 4, 2020

Posted on: November 4, 2020

Influenza Circulating in Snohomish County

Posted on: December 10, 2019