Expected vs Reported Chronic Hepatitis B Infection Cases in Persons with Active Tuberculosis - California, 2016-2020.

Epidemiologic data regarding persons with active tuberculosis (TB) and chronic hepatitis B virus (cHBV) infection are limited because of lack of routine surveillance of cHBV in persons with TB. Potential underdiagnosis of cHBV in California among those with TB is concerning. We matched TB and cHBV registries to identify cHBV infections among persons diagnosed with TB during 2016-2020 and described their demographic characteristics. We calculated expected cHBV cases among persons with TB for each demographic characteristic using published cHBV prevalence estimates for the locations of birth for persons with TB. Estimates were from general or emigrant adult and teen populations. Reported cHBV infection among persons with TB were 23% lower than expected, particularly among Asian persons, persons living in the two healthiest Healthy Places Index quartiles, and residents of less populated jurisdictions in California. Results show the possibility exists for underdiagnosis of cHBV in persons with TB in California.