Widespread Community Transmission of Hepatitis A Virus Following an Outbreak at a Local Restaurant — Virginia, September 2021–September 2022

Discussion

In hepatitis A outbreaks, rapid source identification is critical to interrupting transmission. In this outbreak, RCAHD quickly identified the source; however, because of the long incubation period (15–50 days), a delay in the index patient’s seeking medical attention, and that person not disclosing their occupation during the initial interview, widespread transmission, resulting in 51 cases, 31 hospitalizations, and three deaths, had already occurred. The severity of outcomes associated with the restaurant-associated outbreak was likely due to a combination of the high median patient age and prevalence of comorbidities.

The unvaccinated index patient in this outbreak had risk factors for which hepatitis A vaccine is routinely recommended. Hepatitis A vaccines are safe and effective and became part of the routine childhood vaccination schedule in 2006 (6). Current adult vaccination recommendations focus on “any person who requests vaccination” (7) and disproportionately affected populations that include persons who use drugs, men who have sex with men, persons experiencing homelessness, and international travelers. In the United States during 2011–2016, approximately two thirds of persons who reported injection drug use (67%) and men who have sex with men (64%) reported that they had not been vaccinated against hepatitis A (8).

Despite the association of drug use with widespread U.S. hepatitis A outbreaks, vaccination efforts targeting persons who use drugs is challenging for many reasons, including behavioral health issues, limited engagement in health care systems, and transportation problems (9). A 2013 Substance Abuse and Mental Health Services Administration study found that, among industries, the restaurant industry had the highest rates of drug use, with nearly 20% of food service workers reporting drug use during the preceding month (10). In 2019, the U.S. food industry employed 15.3 million persons, suggesting that nearly 3 million food industry workers might be using drugs.** To improve hepatitis A vaccination coverage among persons who use drugs, public health agencies can explore partnerships with businesses that might employ persons at higher risk for hepatitis A. Persons who use drugs might not disclose being in a high-risk category recommended for hepatitis A vaccination, but might consider vaccination if encouraged by their employer. Health care professionals and public health officials should continue to encourage vaccination among disproportionately affected populations.

The findings in this report are subject to at least four limitations. First, the initial outbreak began during the COVID-19 Delta variant surge, and community transmission of HAV continued during the Omicron variant surge. Pandemic-related response activities in the community might have resulted in underreporting of cases. Second, extensive media coverage of the hepatitis A outbreak might have increased hepatitis A testing in the community, leading to more diagnoses of cases not associated with the outbreak. Third, RCAHD encountered challenges to interviewing patients, which could have resulted in underreporting of risk factors, epidemiologic links, and specific symptoms. This underreporting limited RCAHD’s ability to identify direct epidemiologic linkages between restaurant-associated cases and subsequent community transmission. Finally, because the specific genotype IB sequence identified in these outbreaks is not uncommon, a causal association between the restaurant outbreak and the ongoing person-to-person transmission could not be established.

After years of limited HAV transmission in the Roanoke, Virginia area, hepatitis A cases increased sharply in the community following an initial outbreak associated with an unvaccinated food handler with hepatitis A risk factors. Increasing awareness of risk factors for hepatitis A, particularly among food handlers, and increasing vaccine access for persons at risk, particularly those who use drugs, could help prevent similar outbreaks in other communities.