Number of reported cases* of hepatitis A virus infection and estimated infections — United States, 2013-2020

Number of reported cases* of hepatitis A virus infection and estimated infections† — United States, 2013-2020

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Source: CDC, National Notifiable Diseases Surveillance System.  Reported confirmed cases. For the case definition, see Acute Hepatitis A.

* The number of estimated viral hepatitis infections was determined by multiplying the number of reported cases that met the classification criteria for a confirmed case by a factor that adjusted for underascertainment and underreporting. The 95% bootstrap confidence intervals for the estimated number of infections are displayed in the Appendix.

† Reference: Klevens RM, Liu, S, Roberts H, et al. Estimating acute viral hepatitis infections from nationally reported cases. Am J Public Health 2014; 104:482. PMC3953761.

During 2013–2015, the number of reported cases of hepatitis A ranged from approximately 1,200 to 1,800 cases yearly. The number of reported cases of hepatitis A began to increase during 2016 when 2 foodborne outbreaks were reported, and outbreaks associated with person-to-person transmission, primarily among persons who use drugs and those experiencing homelessness, were first reported.

Outbreaks associated with person-to-person transmission have since been reported in multiple states, resulting in substantial increases in hepatitis A peaking at 18,846 cases in 2019. During 2020, the number of reported cases was 9,952, which corresponds to 19,900 estimated infections after adjusting for case underascertainment and underreporting.

The number of reported cases during 2020 corresponds to a 47% decrease from 2019 but remains more than 7 times the number reported during 2015, before the recent hepatitis A outbreaks associated with person-to-person transmission were first reported.

During 2020, several states declared an end to their outbreaks, while only two states had outbreaks begin. Disruptions to healthcare access and health department surveillance capacity during the COVID-19 pandemic may have affected the ability to detect and report all hepatitis A cases in 2020.

Source:

  1. Klevens RM, Liu, S, Roberts H, et al. Estimating acute viral hepatitis infections from nationally reported cases. Am J Public Health 2014;104:482. PMC3953761.
  2. Centers for Disease Control and Prevention (CDC). Widespread person-to-person outbreaks of hepatitis A across the United States. Atlanta, GA: US Department of Health and Human Services, CDC; 2022.