At a glance
Case ascertainment and case reporting
For health department staff to report cases of viral hepatitis to CDC, systems and processes must be in place to ensure each case is reported. Because of varying state laws, resources, and infrastructure, not all health departments report all cases of perinatal, acute, or chronic viral hepatitis to CDC. Additionally, diagnosing every acute case is impossible because symptoms might be either so mild that the person does not seek care or too vague to prompt a health care provider to suspect and test for viral hepatitis.
Case reporting begins when a local or state health department receives a positive laboratory report, indicating a person has a viral hepatitis infection. Because initial reporting provides limited information and additional laboratory test results or clinical symptoms are frequently needed for classifying cases, reported cases might require extensive follow-up to obtain full information for establishing case status and case classification.
In September 2021, CDC released the Viral Hepatitis Surveillance and Case Management: Guidance for State, Territorial, and Local Health Departments. The publication provides jurisdictional guidance to implement and improve hepatitis A, hepatitis B, and hepatitis C surveillance and case management, including reporting requirements, collection of relevant laboratory data, and case investigation. Given that current systems for the surveillance and follow-up of cases differ by jurisdiction, the standards are designed to provide models for best practices, recognizing that not every jurisdiction can meet those standards with available resources.
Health departments prioritize cases for follow-up using their own protocols and might submit cases to CDC with incomplete or missing information. Additionally, the volume of laboratory reports for viral hepatitis infections might be so large that not all health departments are able to consistently detect and report all acute and chronic cases to CDC. Data regarding chronic hepatitis B and hepatitis C are included where available; however, it is important to note that these are newly reported chronic viral hepatitis cases and do not measure prevalence.
Please note surveillance data are typically finalized in the fall following the year of data collection. However, data may occasionally be updated as needed and thus datasets generated at different time points might yield slightly different results. The date the data were most recently updated is noted below the dashboard under "Sources".
For NNDSS reporting exceptions for viral hepatitis, please click the table icon 
located in the top left corner of the "Rates by State" visual.
NNDSS case definitions
To ensure consistent reporting across states, the Council of State and Territorial Epidemiologists (CSTE), in collaboration with CDC, developed case definitions for viral hepatitis A, hepatitis B, and hepatitis C.
The case definitions facilitate standardized reporting by using uniform criteria and differentiating between acute (hepatitis A, hepatitis B, and hepatitis C), chronic (hepatitis B and hepatitis C), and perinatal cases (hepatitis B and hepatitis C). When new technologies are developed for laboratory testing or better clinical data become available, the case definitions may be updated.
Changes in case definitions should be considered when examining temporal trends. For more information regarding the case definitions used during each year, visit the NNDSS website.
Recent revisions to case definitions for acute and chronic hepatitis C and hepatitis B were implemented in 2020 and 2024, respectively. As outlined in the CSTE Hepatitis C Position Statement, the 2020 acute hepatitis C case definition was developed to emphasize more objective laboratory tests and reduce dependence on subjective and non-specific signs and symptoms. Similarly, changes to the CSTE Hepatitis B Position Statement for acute and chronic hepatitis B case definitions were made to address testing updates and enhance disease burden measurement. These changes include improving the sensitivity and specificity of acute hepatitis B virus infection classifications, refining the criteria for more accurately confirming chronic cases, and establishing a probable case classification for acute hepatitis B.
These recent updates minimize variability of practice in case classification among jurisdictions and are expected to increase the number of hepatitis B and hepatitis C cases based on the previous case definitions. However, the magnitude of the increase in cases reported will vary across jurisdictions. Variation might result from types of positive and negative hepatitis laboratory results and liver function tests (alanine transaminase (ALT) and total bilirubin) that are reportable by law or mandated in the jurisdiction and a jurisdiction's capacity to conduct case investigations. For a comprehensive understanding of all case definition changes, including older revisions, readers are encouraged to visit the NNDSS website.
Estimating incidence of acute viral hepatitis
To account for under ascertainment and underreporting, a probabilistic model for estimating the true incidence of hepatitis A, acute hepatitis B, and acute hepatitis C from reported cases has been previously published. The model includes the probabilities of symptoms, referral to care and treatment, and rates of reporting to local and state health departments; of note, the multipliers for acute hepatitis C have been updated since the original publication (unpublished erratum). The multipliers 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% bootstrap CI: 3.7–15.9); and each reported case of acute hepatitis C represents 13.9 estimated infections (95% bootstrap CI: 11.0–47.4).
Calculation of case rates and population denominators
Rates per 100,000 population were calculated for the number of reported cases of hepatitis A, acute hepatitis B, chronic hepatitis B, acute hepatitis C, and chronic hepatitis C. For these five conditions, rates include the number of cases and population denominators for all states or jurisdictions that do not use the Not Reportable (N) or Unavailable (U) reporting exceptions. Denominators for rates of reported cases of viral hepatitis use population estimates from the US Census Bureau. For the years prior to and including 2020, bridged-race population estimates were used for the calculation of rates. However, the release of bridged-race population estimates ended with the release of the 2020 estimates. Beginning in 2021, single-race population estimates were used to calculate rates.
Figures and tables based on NNDSS data presented in this report use the 1977 Office of Management and Budget (OMB) standards, and race and ethnicity are combined during analysis to create the following five categories: non-Hispanic American Indian/Alaska Native (AI/AN), non-Hispanic Asian/Pacific Islander (A/PI), non-Hispanic Black, non-Hispanic White, and Hispanic. These five categories will continue to be used until newer OMB standards are universally adopted for case notification to CDC. Of note, reporting of data using single-race categories may not be directly comparable with the bridged-race categories and small differences are possible (Race Bridging).
Mortality surveillance and calculation of mortality rates
The National Vital Statistics System (NVSS) provides information regarding deaths that occur in the US. NVSS data in this report are from 2011 to 2023. These data are based on information from all death certificates filed in the vital records offices of the 50 states and the District of Columbia through the Vital Statistics Cooperative Program or coded by NCHS from copies of the original death certificates provided to NCHS by the State registration offices. Deaths of nonresidents (for example, nonresident aliens, nationals living abroad, or residents of US territories) and fetal deaths are excluded. Cause of death is defined as one of the multiple causes of death and is based on the International Classification of Diseases, 10th Revision (ICD-10) codes for each condition: hepatitis A (B15), hepatitis B (B16, B17.0, B18.0, and B18.1), and hepatitis C (B17.1 and B18.2).
Rates per 100,000 population were calculated for the number of deaths where hepatitis A, hepatitis B, or hepatitis C were listed as a cause of death. Overall death rates and rates by race and ethnicity and sex are age-adjusted to the year 2000 standard US population (CDC WONDER's Technical Notes).
For HepTracker, mortality rates for race and ethnicity during 2011–2023 are presented for five categories: non-Hispanic American Indian or Alaska Native (AI/AN), non-Hispanic Asian or Pacific Islander (A/PI), Hispanic, non-Hispanic Black, and non-Hispanic White. Data for the non-Hispanic multiracial category were excluded from the dashboard because this classification is not available in the bridged-race categories used for data prior to 2018. Mortality rates based on bridged-race data are generally similar to those based on single-race data for the total population and larger race groups, but differences may be larger and directionally uncertain for smaller populations (Comparability of Race-specific Mortality).