National Profile of Viral Hepatitis

First-time Investment for Comprehensive National Viral Hepatitis Surveillance

In May 2021, CDC awarded new funding to 59 US states, territories, and large cities to support viral hepatitis surveillance activities. The funding is intended to strengthen surveillance for viral hepatitis; increase partner engagement in elimination planning; and improve access to diagnosis, treatment, and prevention among populations most at risk for viral hepatitis. This represents near national coverage, up from 14 sites funded for surveillance activities during May 2017–April 2021.

Impact of COVID-19

The global COVID-19 pandemic began in March 2020 and continued to cause disruptions in access to medical care and routine public health activities in 2021. Pandemic-related stay-at-home orders suspended or delayed many routine healthcare visits and patients avoided seeking medical and preventative services,² and a decline in testing for hepatitis C was identified.³ Furthermore, many health department staff routinely assigned to viral hepatitis case investigation and surveillance activities were reassigned to respond to the COVID-19 pandemic. The COVID-19 pandemic also had a profound impact on mortality with the overall age-adjusted death rates increasing during 2020 and 2021 compared to 2019.^4,5 For these reasons, the numbers and rates of viral hepatitis cases and deaths associated with viral hepatitis for 2020 and 2021 presented in this report should be interpreted with caution.

Hepatitis A

During 2021, a total of 5,728 hepatitis A cases were reported to CDC by 50 states corresponding to 11,500 estimated infections (95% confidence interval [CI]: 8,000–12,600) after adjusting for case underascertainment and underreporting (see Technical Notes).⁶ The reported case count corresponds to a rate of 1.7 cases per 100,000 population, a 43% decrease from the reported rate of 3.0 cases per 100,000 population during 2020. A continued decrease in the reported rates of hepatitis A in 2021 follows a period of several years of increasing rates due to widespread and prolonged hepatitis A outbreaks associated with person-to-person transmission, primarily occurring among persons who use drugs and those experiencing homelessness.⁷ During 2021, eight states declared an end to their outbreaks. Approximately 55% of all hepatitis A cases reported to CDC during 2021 occurred among persons aged 30–49 years, and 76% occurred among non-Hispanic White persons. Among the 3,026 (53%) reported cases in 2021 that included risk information for injection drug use, 1,341 (44%) reported injection drug use. A total of 2,526 patients were hospitalized (62% hospitalization rate among the 4,043 cases with hospitalization information available).

Data from death certificates filed in the vital records offices of the 50 states and the District of Columbia revealed that the age-adjusted death rate associated with hepatitis A during 2021 among US residents was 0.03 deaths per 100,000 population, a decrease from the rate reported in 2020 of 0.04 per 100,000 population.

Hepatitis B

Reported cases of acute HBV infection decreased after routine vaccination of children was recommended in 1991. The rates of reported cases of acute hepatitis B were relatively stable during 2010–2019 but declined abruptly in 2020. During 2021, a total of 2,045 acute hepatitis B cases were reported to CDC by 47 states, resulting in 13,300 estimated infections (95% CI: 7,600–32,500) after adjusting for case underascertainment and underreporting (see Technical Notes).⁶

The reported case count corresponded to a rate of 0.6 per 100,000 population in 2021, a 14% decrease from the rate in 2020 (0.7 cases per 100,000 population). While the reduction in rate of acute hepatitis B during 2020 and 2021 may be related to hepatitis B prevention activities, it is also likely attributed to 1) disruptions in healthcare access resulting from the COVID-19 pandemic reducing the number of persons tested for HBV infection and 2) reassignment of viral hepatitis surveillance staff in health departments to work on the COVID-19 pandemic, thus limiting their ability to investigate laboratory reports and conduct medical provider follow-up and medical record review required to accurately determine acute case status.

Approximately 73% of all acute hepatitis B cases reported to CDC during 2021 occurred among persons aged 30–59 years. The rate of acute hepatitis B was highest among non-Hispanic Black persons (0.9 cases per 100,000 population), compared with other race and ethnicity groups. Among the 955 (47%) reported cases that included risk information for injection drug use, 289 (30%) reported injection drug use. A total of 766 patients with acute hepatitis B were hospitalized (59% hospitalization rate among 1,299 cases with hospitalization information available).

A total of 14,229 newly reported cases of chronic hepatitis B were reported to CDC by 40 states during 2021, corresponding to a rate of 5.9 cases per 100,000 population; 89% of all chronic hepatitis B cases occurred among persons aged 30 years and older. The rate of newly reported chronic hepatitis B cases was highest among non-Hispanic Asian/Pacific Islander persons (27.0 cases per 100,000 population), which was 14 times the rate among non-Hispanic White persons (1.9 cases per 100,000 population).

A total of 17 perinatal hepatitis B cases were reported through NNDSS to CDC from 10 states during 2021, 7 more cases than reported in 2020. Data from the PHBPP (see Table 4.1 and Figure 4.1) from 64 jurisdictions reported 7,649 infants born to persons with HBV infection during 2020, 95% of whom had received recommended prophylaxis at birth, 86% had completed 3 doses of vaccine by age 12 months, and 65% had received recommended post-vaccination serologic testing. Among 4,975 infants with post-vaccination testing, 20 (0.4%) were cases of perinatal hepatitis B transmission.

Data from death certificates demonstrated that the age-adjusted death rate associated with hepatitis B during 2021 among US residents was 0.44 deaths per 100,000 population, similar to the rate during 2020 (0.45 deaths per 100,000 population). The death rate was highest among non-Hispanic Asian/Pacific Islander persons (2.54 deaths per 100,000 population), almost 10 times the rate among non-Hispanic White persons (0.26 deaths per 100,000 population).

Hepatitis C

During 2021, a total of 5,023 acute hepatitis C cases were reported to CDC from 42 states, corresponding to 69,800 estimated infections (95% CI: 55,300–238,100) after adjusting for case underascertainment and underreporting (see Technical Notes).⁶

The acute hepatitis C case count corresponds to a reported rate of 1.6 cases per 100,000 population, a 60% increase from the reported rate during 2017 (1.0 cases per 100,000 population) and a 7% increase from the reported rate during 2020 (1.5 cases per 100,000 persons).

While the COVID-19 pandemic disrupted healthcare access and reduced the number of persons tested for hepatitis C virus infection,^2,3 anticipated reductions in the number of reported acute hepatitis C cases could have been offset by a change to the acute hepatitis C case definition beginning in 2020. The new case definition was designed to better characterize the number of cases classified as acute hepatitis C (see Technical Notes/Case Definitions).

Approximately 52% of acute hepatitis C cases reported to CDC during 2021 were among persons aged 20–39 years. The rate of reported cases of acute hepatitis C was highest among non-Hispanic American Indian/Alaska Native (AI/AN) persons (2.7 cases per 100,000 population), compared with other race and ethnicity groups. Among the 1,449 (29%) reported acute cases that included risk information for injection drug use, 820 (57%) reported injection drug use. A total of 604 patients with acute hepatitis C were hospitalized (31% hospitalization rate among 1,935 cases with hospitalization information available).

A total of 107,540 cases of newly reported chronic hepatitis C were reported to CDC from 43 states during 2021, corresponding to a rate of 39.8 cases per 100,000 population. The rate of newly reported chronic hepatitis C was highest among persons aged 30–39 years (74.9 cases per 100,000 population), followed by persons aged 40–49 years (54.6 cases per 100,000 population), compared with other age categories, maintaining a previously reported shift in the chronic hepatitis C disease burden from older (above 65 years old) to younger persons (See Figure 3.8).⁸ The rate of newly reported chronic hepatitis C cases was highest among non-Hispanic AI/AN persons (68.9 cases per 100,000 population), compared with other race and ethnicity categories.

A total of 199 perinatal hepatitis C cases were reported to CDC from 28 states during 2021, a 21% increase from the 165 cases reported in 2020, and closer to the 217 cases reported in 2019 before the COVID-19 pandemic occurred.

Data from death certificates filed in the vital records offices of the 50 states and the District of Columbia indicated that the age-adjusted death rate associated with hepatitis C during 2021 was 3.18 deaths per 100,000 population, an 8% decrease compared to the rate during 2020 (3.45 deaths per 100,000 population). The age-adjusted death rate for hepatitis C during 2021 represents a 23% decrease from the rate during 2017 (4.13 deaths per 100,000 population). The death rate among non-Hispanic AI/AN persons (9.99 deaths per 100,000 population) was 3.4 times the rate among non-Hispanic White persons.