Climate-Driven Trends in Pathogen Spectrum of HFMD

Background: Pathogen spectrum is vital during infectious disease epidemics. However, the role of pathogen spectrum during hand, foot, and mouth disease (HFMD) epidemics and the major contributing factors remains unknown.Methods: HFMD cases from 2016 to 2018 in Guangzhou, China were collected. The relationship between HFMD cases and pathogen spectrum, as well as the association between pathogen spectrum and climate factors were studied using general linear models. We transformed the pathogen spectrum to the isometric log-ratio (ILR) components included in the model. Additionlly, vaccination rates were adjusted in the climate driven models.Results: We observed seasonal trends in HFMD cases, pathogen spectrum, and climate factors. The model regressing case numbers on pathogen spectrum revealed negative associations with both the ILRs of CAV16 (RR = 0.725, P<0.001) and EV71 (RR = 0.421, P<0.001). The model regressing pathogen spectrum on driven factors showed that the trends for EV71 proportions were inversely related to vaccination rate (%, β = -0.152, P=0.098) and temperature (°C , β = -0.065, P=0.004). Additionally, the trends for CVA16 proportions were inversely related to vaccination rate (%, β = -0.461, P=0.004) and temperature (°C , β = -0.068, P=0.031). The overall trends for pathogen spectrum showed that EV71 decreased significantly, while the trends for CVA16 increased annually.Conclusions: Our findings suggest a potential pathway for climate factors - pathogen spectrum - HFMD cases. Our study is practical and useful for targeted prevention and control, as well as provides environmental-based evidence.