Ecological signature on the epidemiological dynamics of severe fever with thrombocytopenia syndrome.

BACKGROUND

Severe fever with thrombocytopenia syndrome (SFTS) is prioritized as an emerging tick-borne disease, posing a continuing threat to human populations. Existing evidence has shown that tick-to-human transmission is the primary route of human infection. However, this insight has not been consistently incorporated into studies examining the ecological dependence of vectored disease dynamics.

METHODS

We employ an eco-epidemiological model to assess tick abundance in response to the natural environment and its contribution to SFTS transmission. Our statistical model, which integrates demographic, ecological, and behavioural factors, investigates how vector abundance impacts case fatality risk.

RESULTS

Our findings identified a shift in peak incidence from July to May among endemic counties since 2021. Additionally, we show that local climate conditions influence SFTS dynamics by modulating local vector populations, revealing clear spatial heterogeneity in transmission potential across endemic counties. Further investigations suggest that the odds of death are higher for patients living in the areas with higher tick abundance.

CONCLUSIONS

These insights emphasize the profound influence of ecological factors on disease dynamics and severity. Therefore, understanding the interrelation between climate and vector population dynamics is crucial for both research and policymaking related to climate-sensitive vectored diseases.