Similar clinical presentations, divergent epidemiological profiles and environmental drivers: a national comparative study of amoebic and bacillary dysentery in China, 2005–2020

Although amoebic dysentery (caused by Entamoeba histolytica) and bacillary dysentery (caused by Shigella spp.) share highly similar clinical manifestations, their epidemiological profiles and transmission ecologies are likely to be distinct. The lack of systematic and comprehensive comparative analyses poses a challenge to guiding pathogen-specific interventions. We conducted a retrospective analysis of nationally notifiable surveillance data of amoebic and bacillary dysentery in mainland China from 2005 to 2020. We applied an age–period–cohort (APC) model to quantify longitudinal trends, a Bayesian space–time hierarchical model (BSTHM) to map the spatiotemporal heterogeneity, and an optimal parameters–based geographical detector (OPGD) to assess the distinct drivers driving transmission for each pathogen. A total of 28,889 cases of amoebic and 3,444,305 cases of bacillary dysentery were reported in mainland China from 2005 to 2020. Both diseases exhibited marked summer–autumn seasonality and a predilection for children <5 years. However, their geographical architectures were fundamentally divergent: Amoebic dysentery was hyper–endemic in the humid southwest (Guizhou, Hunan, Guangxi), primarily explained by socioeconomic drivers (medical personnel density: Q = 20.12%, and GDP: Q = 18.17%). In contrast, bacillary dysentery hot spots spanned arid western provinces and the densely populated Beijing–Tianjin region, showing stronger associations with environmental and demographic drivers (population density: Q = 39.11%, relative humidity: Q = 19.12%, temperature: Q = 18.85%, and rainfall: Q = 17.53%). This study delineates the distinct eco–epidemiological profiles of dysentery in mainland China. The divergent drivers underscore the necessity of transitioning from generic diarrheal disease control to pathogen–specific precision public health strategies and interventions.