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Number of reported cases* of Hepatitis A virus infection and estimated infections† — United States, 2014–2021
* 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.
The number of reported cases of hepatitis A began to increase during 2016 when two foodborne outbreaks and multiple 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,1 resulting in substantial increases in hepatitis A peaking at 18,846 reported cases in 2019, then declining in 2020. During 2021, the number of reported cases was 5,728, which corresponds to 11,500 estimated infections after adjusting for case underascertainment and underreporting.2 The number of reported cases during 2021 corresponds to a 42% decrease from 2020 but remains four times the number reported during 2015, before the hepatitis A outbreaks associated with person-to-person transmission were first reported. During 2021, eight states declared an end to their outbreaks. 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 and 2021.
Source:
- 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.
- 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.
- Figure 1.1. Number of reported cases of hepatitis A virus infection and estimated infections — United States, 2014–2021
- Figure 1.2. Rates of reported cases of hepatitis A virus infection, by state or jurisdiction — United States, 2020–2021
- Figure 1.3. Rates of reported cases of hepatitis A virus infection, by state or jurisdiction — United States, 2021
- Figure 1.4. Rates of reported cases of hepatitis A virus infection, by age group — United States, 2006–2021
- Figure 1.5. Rates of reported cases of hepatitis A virus infection, by sex — United States, 2006–2021
- Figure 1.6. Rates of reported cases of hepatitis A virus infection, by race/ethnicity — United States, 2006–2021
- Figure 1.7. Availability of information regarding risk behaviors or exposures associated with reported cases of hepatitis A virus infection — United States, 2021
- Table 1.1. Numbers and rates of reported cases of hepatitis A virus infection, by state or jurisdiction — United States, 2017–2021
- Table 1.2. Numbers and rates of reported cases of hepatitis A virus infection, by demographic characteristics — United States, 2017–2021
- Table 1.3. Reported risk behaviors or exposures among reported cases of hepatitis A virus infection — United States, 2021
- Table 1.4. Numbers and rates of deaths with hepatitis A virus infection listed as a cause of death among residents, by demographic characteristics — United States, 2017–2021