Substantial underdiagnosis and underreporting: changes in reported HIV and AIDS cases in 31 provinces in China at the beginning of COVID-19

Background China implemented extensive non-pharmaceutical interventions (NPIs) to contain COVID-19. Methods National and provincial data on monthly reported HIV and AIDS cases from January 2017 to December 2020 were collected from the National Health Commission of the People's Republic of China. We used interrupted time series analysis to assess whether COVID-19-related NPIs had an impact on reported HIV and AIDS cases in 31 provinces in China, and estimated underreported numbers of HIV and AIDS cases in the first month of the COVID-19 pandemic. Results A total of 393,357 HIV cases and 254,735 AIDS cases were recorded in China from January 2017 to December 2020. Nationally, the number of reported HIV cases decreased by 25.1% in the first month of the NPIs period (January 2020) compared with the counterfactual (incidence rate ratio (IRR) 0.749; 95% confidence interval (CI) 0.664-0.845), whereas the number of reported AIDS cases decreased by 36.5% (IRR 0.635, 95% CI 0.543-0.741). An estimated 2208 HIV cases (95% CI 1209-3335) and 1525 AIDS cases (95% CI 927-2233) were underdiagnosed and underreported in the first month of the NPIs in China. The highest numbers of underdiagnosed and underreported HIV cases in the first month of NPIs were estimated in Sichuan (IRR 577, 95% CI 239-978), Guangdong (IRR 185, 95% CI 170-200) and Henan (IRR 170, 95% CI 77-286). Conclusions There was substantial underdiagnosis and underreporting of HIV and AIDS cases during the first month of the COVID-19 pandemic in China and certain provinces. Health departments should consider the specific barriers encountered during the pandemic, such as disrupted healthcare access and resource limitations, and implement targeted strategies to strengthen HIV surveillance and report systems.