Steep reduction in local cases of hepatitis A among people living homeless

On October 29, the Washington State Department of Health declared that the statewide hepatitis A outbreak appears to be over. We’re happy to announce that this reduction in hepatitis A cases is true locally, as well. Numbers of new hepatitis case reports locally are now lower than the numbers of cases seen prior to the start of the outbreak.  

This major reduction in cases is thanks to King County’s early investment in an extensive free vaccination program and help from community partners, including Harborview Medical Center, VA Puget Sound, community clinics, Evergreen Treatment Services’ REACH program, Operation Nightwatch, and Downtown Emergency Services Center.  

Not only is this good news for the public’s health, but these early investments in preventative care likely avoided greater costs for the County in response to an even larger outbreak.  

Hepatitis A cases in King County

From January 2019, through September 2021, a total of 199 King County residents infected with hepatitis A were reported to Public Health. This included 122 hospitalizations and two deaths. Most of these infections were in people who were living homeless or who use drugs. For comparison, from 2010 to 2019, there were just 5 to 16 cases of hepatitis A reported in King County residents each year. (For more data on case counts and demographics of hepatitis A cases during this outbreak, visit King County’s Hepatitis A Outbreak Data Dashboard.) 

A bar graph detailing King County hepatitis A cases from January 2019 to present date.

This increase in cases came in the context of cities and states across the country experiencing very large hepatitis A outbreaks in recent years, with some states reporting thousands of cases, hundreds to thousands of hospitalizations, as well as dozens of deaths. These outbreaks were also very costly to address; San Diego County in California spent over $12 million responding to their outbreak. 

While hepatitis A cases in the United States have historically been linked to international travel or contaminated food products, most recent infections in King County have been through person-to-person transmission, especially among people who are living homeless or who use drugs. This population is at higher risk for hepatitis A because they may have limited access to hygiene resources, such as soap and warm water for handwashing. If someone infected with hepatitis A doesn’t wash their hands well, especially after using the toilet, undetectable amounts of the virus can spread from the hands of that person to other objects, surfaces, and foods, and easily infect others. 


King County invested heavily in public health actions and community partnerships to prevent the spread of hepatitis A, particularly to provide free hepatitis A vaccines, which is one of the most effective tools to prevent infection and to help mitigate a major outbreak. Seeing large scale hepatitis A outbreaks spreading across states, Public Health began holding free hepatitis A vaccination clinics and working with area healthcare providers to provide hepatitis A vaccination for people living homeless starting in fall 2017, before we had identified any cases among people living homeless.  

Public Health increased this vaccination push in July 2019, when King County allocated $375,000 towards these efforts. We continued this vaccination work in 2020 thanks to King County allocating an additional $322,000 for hepatitis A prevention. 

Thanks in large part to these investments, since January 2019, Public Health and Public Health Reserve Corps staff vaccinated over 3,500 people against hepatitis A, at nearly 1,000 free vaccination clinics at shelters, day centers, villages and other sites serving people who are living homeless or using drugs.  

“The steep decrease in hepatitis A cases and prevention of a larger outbreak locally is an excellent example of what investment in public health can accomplish,” said Dr. Jeff Duchin, Health Officer for Public Health – Seattle & King County. “The hepatitis A outbreak among people living homeless was complex and required multiple, sustained labor-intensive interventions and collaboration with community stakeholders and healthcare system partners. I’m proud of our staff, community partners, and government leaders, and grateful to people who stepped up to get vaccinated and take other action to prevent hepatitis A from spreading.” 

Public Health worked closely with healthcare partners, including the Hepatitis Education Project, Harborview Medical Center, Swedish Medical Center, VA Puget Sound and community clinics, who have provided over 6,000 hepatitis A vaccines in 2019, targeting people at high risk, including those who are unstably housed, people who use drugs, and men who have sex with men. Public Health also worked closely with community partners, including Evergreen Treatment Services’ REACH program, Operation Nightwatch, and Downtown Emergency Services Center to provide hepatitis A outreach, education and hygiene kits to people living homeless. 

“In response to the hepatitis A outbreak in King County, Harborview Medical Center worked hard to make hepatitis A vaccination widely available,” said Dr. Herbie Duber, Associate Professor of Emergency Medicine, University of Washington School of Medicine/Harborview Medical Center. “This includes our Emergency Department, where we offer hepatitis A vaccination for any patients who have risk factors for the disease. It’s systematized, preventative care steps like these that can help keep our entire community healthier. We’re grateful to the many community partners and other healthcare providers who have helped increase hepatitis A vaccination rates locally and likely prevented what could have been a much larger and more costly outbreak.”  

“This successful hepatitis A vaccination campaign is the result of years of thoughtful work among Public Health staff, partners and volunteers, who built relationships with people who are often hesitant to get vaccinated due to government and medical system disenfranchisement,” said Dennis Worsham, Interim Director for Public Health. “I’m proud that our County invested early to provide vital preventative care to a vulnerable community – this was an equity issue but, also, a cost saving move, as we avoided spending millions responding to the kind of massive outbreaks we’ve seen in other parts of the country.” 

More about hepatitis A 

Hepatitis A virus infects the liver and can cause illness that ranges from a mild infection that has no symptoms to a more severe illness that can last for months. On rare occasions, hepatitis A infection can cause liver failure and death. People with underlying liver disease and people over 50 years of age are at increased risk for severe hepatitis A infections. 

Hepatitis A vaccine has been part of the routine childhood vaccination schedule in the United States since 2006. Most adults were not vaccinated as children. 

For more information about hepatitis A, visit King County’s hepatitis A webpage

Originally published October 29, 2021