Epidemiological trends and clinical characteristics of human leptospirosis in Wenzhou, Zhejiang Province, China, 2020-2022.

Objective: To observe the clinical characteristics and epidemic trends of human leptospirosis in Wenzhou, Zhejiang Province, China, from 2020 to 2022 and to provide a scientific basis for prevention and control in this area.

Methods: Descriptive epidemiological methods were used in Wenzhou, China, from 2020 to 2022. Leptospira antibodies were detected by a microscopic agglutination test (MAT), and laboratory tests were conducted to analyse the prevalence of Leptospira in the population.

Results: From 2020 to 2022, a total of 41 cases of human leptospirosis were reported in Wenzhou, China, with no deaths and an average annual incidence of 0.1428/100,000. The highest incidence was in 2021 (30 cases, incidence rate: 0.31/100,000), and the lowest incidence was in 2022 (three cases, incidence rate: 0.04/100,000). The high-incidence season was from August to October, in which a total of 36 cases were reported, accounting for 87.80% of total cases, most of which were males. The main occupation was farming, which accounted for 70.7% of the total number of cases. 90.2% of cases had fever symptoms, and the body temperature was between 36.5 ℃ and 40.1 ℃. A total of 32 positive samples were detected by MAT in six main groups, mainly the Autumnalis serogroup.

Conclusions: The incidence of leptospirosis in Wenzhou, China, was at a moderate level from 2020 to 2022. Localities should actively strengthen the monitoring of leptospirosis host animals and populations, understand the infection rate and floral changes and prevent leptospirosis outbreaks.