Number of reported acute viral hepatitis cases* and estimated infections^† with 95% bootstrap confidence intervals — United States, 2013-2020

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).

This model has not been recalibrated to account for the change in the acute hepatitis C case definition that occurred in 2020, and as such estimated infections of acute hepatitis C generated for 2020 may require revision in the future. Work is underway to update the multipliers for hepatitis A, hepatitis B, and hepatitis C using updated literature.