Life-course restructuring of infectious mortality in China, 2004-2021: a national surveillance study

While China has achieved significant milestones in controlling infectious diseases, how mortality patterns have shifted across different life stages remains poorly understood. This study aims to delineate the evolving burden of infectious disease mortality to inform age-specific public health strategies.

We analyzed national death surveillance data from China spanning 2004 to 2021. "Combined infectious mortality" was defined as the aggregate of communicable and parasitic diseases plus respiratory infections. Focusing on four key categories-respiratory infections, tuberculosis, viral hepatitis, and HIV/AIDS-we calculated crude and age-standardized mortality rates (ASMR). Log-linear regression models estimated annual percentage changes (EAPCs). Primary trend inferences were restricted to 2013-2019 (stable post-expansion period); 2020-2021 was treated separately due to the absence of a COVID-19 code.

During 2013-2019, mortality declined substantially faster in younger than in older age groups: EAPC was -14.70% (95% CI -16.96 to -12.38) for children aged 0-4 years, but only -1.62% (95% CI -3.66 to 0.46) for adults aged 75 + (interaction p < 0.0001). In 2021, over half (55.04%) of combined infectious deaths occurred in adults aged 75+. Cause hierarchy varied by age: respiratory infections dominated at both extremes; HIV/AIDS ranked highest among young adults (20-39 years), though its advantage was narrow; viral hepatitis predominated in middle-aged adults (40-59 years). HIV/AIDS mortality rose among 60-74 year-olds (EAPC 5.90% per year), with higher burden in rural and western regions.

China is undergoing a distinctive epidemiological transition: infectious deaths are increasingly concentrated in older age groups, driven primarily by divergent age-specific mortality trends rather than population ageing alone. Public health strategies must extend beyond maternal-child health frameworks to address growing vulnerabilities in older populations-particularly respiratory infections and HIV in ageing rural communities.