Epidemiological Characteristics of Leptospirosis and Animal Surveillance in a High-Risk Rural Area of Eastern China
Shufen Yang, Zhiwei Cheng, Baifu Zheng, Qianqian Liang, Mengtian Zhang, Yihan LuBackground:
Leptospirosis is a globally distributed zoonotic disease that remains a significant public health concern, yet integrated evidence linking human infection, animal reservoirs, and
Methods:
A retrospective and field-based surveillance study was conducted from 2007 to 2025. Descriptive methods were used to analyze temporal, spatial, and demographic characteristics of human leptospirosis cases. Animal surveillance was conducted across multiple host species to assess infection status and
Results:
A total of 53 human leptospirosis cases were reported, with a marked peak in 2007 and no fatalities. Cases were concentrated in late summer and primarily affected middle-aged farmers, with no significant spatial clustering observed. Animal surveillance identified 5630 samples with an overall positivity rate of 2.58%. Infections were detected in rodents, frogs, and ducks, while pigs and cattle were negative. Rodents and frogs were exclusively associated with Icterohaemorrhagiae, whereas ducks exhibited multiple serogroups. Rodent density was positively correlated with human cases, while no association was observed between infection positivity rates and human incidence.
Conclusion:
Leptospirosis in Pan’an is characterized by a stable Icterohaemorrhagiae-dominated transmission system primarily maintained by rodent reservoirs, with human infection occurring through occupational and environmental exposure in agricultural settings. Aquatic-associated animals such as frogs and ducks likely function as environmental interface hosts within a One Health transmission framework. These findings suggest a rodent-associated transmission cycle and support the value of integrated human–animal–environment surveillance for leptospirosis control in rural endemic regions.