Prevalence and awareness of Hepatitis B virus infection in the United States: January 2017 - March 2020

Background:

Prevalence and awareness of HBV infection are important national indicators of progress toward hepatitis B elimination.

Methods:

National Health and Nutrition Examination Survey participants were examined for laboratory evidence of HBV infection (positive antibody to HBcAg and HBsAg), and interviewed to determine awareness of HBV infection. Estimates of HBV infection prevalence and awareness were calculated for the US population.

Findings:

Among National Health and Nutrition Examination Survey participants aged 6 years and older evaluated from January 2017 through March 2020, an estimated 0.2% had HBV infection; of these 50% were aware of their infection.

INTRODUCTION

During the years 2013–2016, only 32% of US persons aged 6 years and older with HBV infection were estimated to be aware of their infection status.1 As part of hepatitis B elimination planning, the US Department of Health and Human Services established a goal to increase this proportion to 90% by 2030.1

During the years 2013–2018, 880,000 persons or 0.3% of the US population aged 6 years and older were estimated to have HBV infection; among these persons, 69.1% were non–US-born, and the prevalence of HBV infection was highest among non-Hispanic (NH) Asian persons.2

We undertook this analysis to measure progress toward US hepatitis B elimination goals, including the prevalence and awareness of HBV infection status in US populations from 2017–March 2020.

METHODS

The National Health and Nutrition Examination Survey (NHANES) is a nationally representative sample survey. We used the NHANES 2017–March 2020 prepandemic file3 to estimate the prevalence and awareness of HBV infection in the US. The Centers for Disease Control and Prevention determined this analysis of existing deidentified data did not require institutional review board approval.

Consenting NHANES participants aged 6 years and older had their serum tested for antibodies to HBcAg (anti-HBc); if anti-HBc-positive, their serum was also tested for HBsAg. Persons who were anti-HBc-positive were classified as having past or present hepatitis B, and persons who were positive for both anti-HBc and HBsAg were classified as having HBV infection. All participants were interviewed about race, Hispanic origin, place of birth, health insurance, and whether they had ever been told they had hepatitis B.

Statistical analysis

Estimates and 95% confidence intervals (CIs) accounting for the survey design were calculated for the prevalence of past or present hepatitis B and HBV infection. Proportions of participants with HBsAg who were aware of their infection were weighted to reflect the multistage, clustered sampling design, and 95% Clopper-Pearson exact CIs were adjusted using the Korn and Graubard adjustment. The reliability of estimates was assessed by applying published standards.3

RESULTS

From January 2017 to March 2020, 10,917 NHANES participants had a blood sample tested for anti-HBc. Of 641 persons who tested positive for anti-HBc, 640 had laboratory results for HBsAg; 45 tested positive for HBsAg, 44 of whom responded to the question about awareness (Table 1).

TABLE 1.

Prevalence of hepatitis B and percent aware of their infection—US, 2017–March 2020

Characteristic	Unweighted number tested for hepatitis B	Unweighted number with hepatitis B	Prevalence, % (95% CI)	Prevalence, (95% CI)
Prevalence of HBV infection (HBsAg+)
Aged 6 y and older
Overall	10,915	45	0.2 (0.1–0.3)	660,000 (410,000–1,000,000)
Aged 20 y and older
Overall	7972	45	0.3 (0.2–0.4)	640,000 (390,000–1,000,000)
NH-Asian persons	951	24	2.2 (1.4–3.5)	320,000 (190,000–490,000)
NH-Black persons	2,036	13	0.5 (0.2–0.9)	140,000 (60,000–270,000)
Born outside the US	2,329	34	1.0 (0.6–1.5)	480,000 (300,000–720,000)
Any public health insurancea	3,812	19	0.2 (0.1–0.4)	210,000 (90,000–430,000)
Only private health insurancea	2,848	19	0.3 (0.1–0.6)	310,000 (130,000–630,000)
Ever told had HBV infection among persons with hepatitis B (HBsAg+)
Characteristic	Unweighted number with hepatitis B	Unweighted number ever told had hepatitis B	Prevalence, % (95% CIb)	Prevalence, (95% CI)
Aged 6 y and older
Overall	44	22	49.8c (25.1–74.6)	330,000 (170,000–490,000)
NH-Asian persons	23	13	62.3c (19.2–94.0)	200,000 (60,000–300,000)
Born outside the US	33	16	56.4c (28.8–81.3)	270,000 (140,000–390,000)
Aged 20 and older
Overall	44	22	49.8c (25.1–74.6)	320,000 (160,000–480,000)
NH-Asian persons	23	13	62.3c (19.2–94.0)	200,000 (60,000–300,000)
Born outside the US	33	16	56.4c (28.8–81.3)	270,000 (140,000–390,000)

^a Any public health insurance was defined as having Medicaid, State Children’s Health Insurance Program, Medicare, or state or other government sponsored health insurance. Only private health insurance was defined as having no public health insurance and any private health insurance plan other than a single service plan.

^b 95% exact Clopper-Pearson CIs with the Korn and Graubard adjustment for complex sample surveys.

^c Estimates do not meet National Center for Health Statistics standards for display of proportions because the absolute value of the CI width exceeds 30%. The absolute value of the unrounded CI width is 49.5% for the overall estimate, 74.8% among NH-Asian persons, and 52.5% among persons born outside the US.

Abbreviation: NH, non-Hispanic.

Among persons aged 6 years and older, 4.0% (95% CI: 3.1%–4.9%) had past or present hepatitis B; and 0.2% (95% CI: 0.1%–0.3%) or an estimated 660,000 (95% CI: 410,000–1,000,000) persons had HBV infection, among whom 49.8% (95% CI: 25.1%–74.6%) were aware of their infection. Among NH-Asian persons, 1.9% (95% CI: 1.2%–2.9%) had HBV infection for an estimated 320,000 (95% CI: 200,000–490,000) persons, among whom 62.3% (95% CI: 19.2%–94.0%) were aware of their infection. Among non–US-born persons, 1.0% (95% CI: 0.6%–1.4%) had HBV infection for an estimated 480,000 (95% CI: 300,000–730,000) persons, among whom 56.4% (95% CI: 28.8%–81.3%) were aware of their infection. NH-Asian persons accounted for 48.4% (95% CI: 30.6%–66.5%) and non–US-born persons accounted for 73.6% (95% CI: 50.6%–90.0%) of all persons with HBV infection.

No persons under the age of 20 years were identified with HBV infection; therefore, estimates for persons aged 20 years or older are included in Table 1.

DISCUSSION

Based on the 2017–March 2020 NHANES data, an estimated 660,000 persons in the US age 6 years and older had HBV infection, and 50% were aware of their infection. Almost half of the persons with HBV infection were NH Asian, and almost three-quarters were born outside the US.

Among persons with hepatitis B, antiviral therapy is associated with reductions in HCC,4,5 cirrhosis,4 and mortality.5 However, studies in communities and health care systems demonstrate testing rates of only 22%–76% among non–US-born persons.6,7 One-time universal screening for all adults in the US is now recommended,8 and some state and local health departments are planning towards the elimination of hepatitis B.9 Respectful ongoing outreach to non–US-born persons is also needed to improve testing and increase awareness.

While HBV infection prevalence among persons aged 6–19 years has been too low to track changes using NHANES since 1999, Centers for Disease Control and Prevention was notified of 265 cases of chronic hepatitis B among persons aged 0–19 years and 17 infants with perinatal hepatitis B in 2019, according to a recent review.10 These low rates of HBV infection among persons aged younger than 20 years are related to comprehensive perinatal, infant, and childhood immunization programs.10

There are at least 4 major limitations to the use of NHANES data for estimates of prevalence and awareness of HBV infection. First, response rates are ~50% for most age groups. Second, NHANES excludes persons experiencing unsheltered homelessness or incarceration, active-duty military, and residents of long-term care facilities. Third, because of the small sample size, the awareness estimate for persons aged younger than 6 years during this timeframe is an imprecise measurement, as reflected in the wide CIs, not statistically different from the previous estimates of 32%–34%.1,2 Similarly, the current prevalence estimate is not statistically different from the previous estimate of 880,000.2 Sample size further limits subgroup analyses that can be performed. Finally, because of the pandemic, data collection for NHANES was suspended beginning in March 2020 for more than 1 year. These last 2 limitations affect the utility of NHANES to monitor HBV infection prevalence and awareness during the 2017–2023 data reporting period for the 2025 Department of Health and Human Services Viral Hepatitis National Strategic Plan.

Hepatitis B is a serious illness that can only be addressed if individuals know they are infected and receive adequate medical evaluation. These data demonstrate continued challenges in meeting Department of Health and Human Services viral hepatitis elimination goals for 2030. Because of the limitations of NHANES data, researchers should also investigate other data sources to estimate the prevalence and awareness of HBV infection in the US. Universal hepatitis B screening recommendations, in combination with expanded use of electronic health records to identify persons due for testing and treatment, might greatly improve diagnosis, quality of care, and outcomes for persons with hepatitis B.