# Number of reported acute viral Hepatitis cases^{*} and estimated infections^{†} with 95% bootstrap confidence intervals — United States, 2014–2021

* Reported confirmed cases. For case definitions, visit Surveillance Case Definitions for Current and Historical Conditions.

† 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.

To account for underascertainment and underreporting, a probabilistic model to estimate the true incidence (symptomatic and asymptomatic cases) of acute hepatitis A, hepatitis B, and hepatitis C from reported (symptomatic) cases has been published previously.

The model includes the probabilities of symptoms, referral to care and treatment, and rates of reporting to local and state health departments. The published multipliers have since been corrected by CDC to indicate that each reported case of hepatitis A represents 2.0 estimated infections (95% bootstrap confidence interval [CI]: 1.4–2.2), each reported case of acute hepatitis B represents 6.5 estimated infections (95% CI: 3.7–15.9), and each reported case of hepatitis C represents 13.9 estimated infections (95% CI: 11.0–47.4). Work is underway to update the multipliers for hepatitis A, hepatitis B, and hepatitis C using updated literature.

- Appendix Table 5.1. Number of reported acute viral hepatitis cases and estimated infections with 95% bootstrap confidence intervals — United States, 2014–2021
- Appendix Table 5.2. Number of reported acute and chronic cases of hepatitis C virus infection by case status — United States, 2021
- Appendix Table 5.3. Numbers and rates of reported acute hepatitis B infections and acute hepatitis C infections among adults aged 18–40 years old, by demographic characteristics — United States, 2021

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.