Abstract
BACKGROUND: The onset of COVID-19 and subsequent restrictive measures have impacted various infectious diseases, including hepatitis B virus (HBV). This study explored the epidemiological characteristics of HBV infection in Chinese adults before, during the pandemic, and after the easing of restrictive measures. METHODS: This population-based cohort study used the data from 23,316 adult patients in the southwest of China who had HBV DNA tests from 1 January 2018 to 31 December 2023. HBV DNA was detected in patient serum using real-time fluorescent quantitative PCR. The positive rate of HBV detection was adjusted by age groups, sex, patient types, and seasons, stratified by the stages of the COVID-19 pandemic. RESULTS: Our analysis revealed significant variations in HBV DNA test positivity rates, primarily influenced by age and the pandemic stages. Positivity rates were highest in the 18-25 age group at 0.50 and decreased with advancing age. Males under 35 were at higher risk. Inpatients had the highest positivity rate at 0.42, with seasonal fluctuations peaking in winter. The pandemic stages significantly affected positivity rates, especially in the 36-45 and 56-65 age groups. CONCLUSION: The findings highlight a complex interplay between pandemic conditions and observed positivity rates. The increase likely stemmed from multiple factors, including shifted testing focus, altered healthcare-seeking behavior, and potential viral reactivation. The COVID-19 response offers insights for optimizing future viral hepatitis control strategies during public health emergencies. Future research should expand demographic and geographic scope and investigate behavioral/social determinants to elucidate underlying mechanisms and guide targeted interventions.