A Quick Update on Hepatitis A in the United States

The Department of Health in New Jersey and the Camden County Health Department are advising people who visited a Starbucks in Camden County to be on the lookout for signs and symptoms of hepatitis A, and to consider receiving the hepatitis A vaccine (HAV) if they haven’t done so already. According to news reports: “Based on the investigation and out of an abundance of caution, the Department of Health recommends any member of the public that patronized the Starbucks facility on Nov. 4, 5, 6, 11, 12 and 13 to get the hepatitis A vaccine.”

The hepatitis A vaccine was developed in the early 1990s by Maurice Hilleman while working at Merck & Co. Initially, the vaccine (named Vaqta) was recommended for children at high risk of contracting hepatitis A. By 2006, the hepatitis A vaccine was recommended for all children in the United States starting at 12 months of age, with earlier ages recommended to get the first dose of the two-dose series if they are traveling to places where hepatitis A is endemic. This recommendation resulted in a 96% reduction in the incidence of hepatitis A in the United States, yet outbreaks continue to occur involving large numbers of people.

World map showing areas of high, medium, low, and no risk of Hepatitis A by country.
Low Risk ≠ No Risk

Because of the relatively recent recommendation to include HAV in the childhood immunization schedule, many young and older adults are not immune. With the availability of water sanitation and food preparation regulations, hepatitis A is not highly endemic in the United States. However, outbreaks happen, and the Centers for Disease Control and Prevention (CDC) has a handy tracking tool of outbreaks of hepatitis A:

Map of the United States showing cases of hepatitis A involved in outbreaks as of November 12, 2021.

As you can see, Kentucky has reported over 4,000 cases of hepatitis A in the outbreak that has been going on there since 2017. Unlike outbreaks in other parts of the world, the outbreak in Kentucky does not seem to be associated with contaminated food or water. Instead, the outbreak is associated with illicit drug use (especially among individuals who use intravenous drugs) and among unhoused people. That outbreak, which is also associated with cases in other states, has also led to deaths. According to the Kentucky Department of Health, HAV coverage among 2 years olds ranges from about 18% to 45% by county:

Map of Kentucky showing counties colored by rate of hepatitis A vaccine coverage.
NOTE: This map shows 2-doses. The vaccine coverage with at least one dose may be higher.

In the State of Washington, a hepatitis A outbreak was just declared over after over two years and resulted in 465 cases, 263 hospitalizations, and 9 deaths. Between 2017 and 2018, an outbreak of hepatitis A in San Diego County, California, caused 592 cases and 20 deaths. In both of these outbreaks, massive vaccination campaigns took place, aimed at people at high risk of contracting the disease.

Author: René F. Najera, DrPH

I am the editor of the History of Vaccines site, an online project by the College of Physicians of Philadelphia. All opinions expressed on these blog posts are not necessarily those of the College or any of my employers. Check out my professional profile on LinkedIn: https://www.linkedin.com/in/renenajera Feel free to follow me on Twitter: @EpiRen

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