Epidemiology of Chronic Hepatitis B Virus Infection, Alameda County, California, 2017-2021.

CONTEXT In the United States, chronic hepatitis B (CHB) virus infection predominantly affects ethnic minorities and vulnerable populations. OBJECTIVE We analyzed surveillance data to describe CHB epidemiology to guide hepatitis B virus (HBV) elimination efforts in Alameda County. DESIGN Persons with CHB during 2017-2021 were identified by ≥2 positive HBV tests (ie, HBsAg, HbeAg, and HBV DNA) ≥180 days apart using data from California Reportable Disease Information Exchange. Persons with CHB were stratified by age, race/ethnicity, zip code-based Healthy Places Index (HPI), and federally designated Medically Underserved Areas (MUA). Comparisons of reported CHB prevalence between groups utilized z test; comparisons between MUA regions utilized chi-square testing. RESULTS A total of 8122 persons with CHB were identified; reported 5-year CHB prevalence was 0.53% (95% confidence interval: 0.52%-0.54%). Reported CHB 5-year prevalence was significantly higher among persons aged 50 to 69 years old than persons aged 30 to 49 years old (0.99%, 0.78%; P < .001) and Asians, Native Hawaiian/Pacific Islanders, African Americans compared to Whites (1.22%, 0.56%, 0.18%, 0.06%; P < .001). Reported CHB 5-year prevalence in the 2 lowest and most disadvantaged HPI quartiles was significantly higher than the 2 highest quartiles (0.55%, 0.68%, 0.37%, 0.42%; P < .001). The 1918 persons with CHB in MUA, compared to 5859 non-MUA persons, were significantly more likely to be African American (7%, 3%; P < .001) and from the lowest HPI quartile (79%, 19%; P < .001). CONCLUSIONS Reported CHB 5-year prevalence in Alameda County was 1.5 times the national prevalence estimates, and reported prevalence was highest among Asians and persons in more disadvantaged areas. Analysis of local CHB surveillance data can guide public health efforts toward HBV elimination.