[Epidemiological characteristics of leptospirosis in China from 2010 to 2022].

Abstract

Objective: To analyze the epidemiological characteristics of leptospirosis in China from 2010 to 2022, so as to provide insights into formulation of the leptospirosis control strategy.

Methods: All data pertaining to clinically diagnosed cases and confirmed cases of leptospirosis reported in China from January 1, 2010 to December 31, 2022 was collected from Chinese Disease Prevention and Control Information Management System. The spatial, temporal and population distributions, and report and diagnosis institutions of leptospirosis cases were analyzed using a descriptive epidemiological method.

Results: A total of 4 559 leptospirosis cases were reported in China from 2010 to 2022, with an annual average number of 351 cases, and the number of reported leptospirosis cases reduced from 679 cases in 2010 to 158 cases in 2018. A total of 4 276 leptospirosis cases were reported in Sichuan Province, Yunnan Province, Guangdong Province, Hunan Province, Fujian Province, Zhejiang Province, Guangxi Zhuang Autonomous Region, Anhui Province, Jiangxi Province and Guizhou Province, accounting for 93.79% of the total number of leptospirosis cases in China. The number of leptospirosis cases had recently appeared a remarkable decline in Yunnan Province, while a significant rise was seen in the number of leptospirosis cases in two provinces of Zhejiang and Guangdong. No leptospirosis cases were reported in Henan Province from 2010 to 2020; however, there were 5 cases and 2 cases reported in 2021 and 2022, respectively. There was only one leptospirosis case reported in Shaanxi Province from 2010 to 2017; however, leptospirosis cases were reported in the province for 5 consecutive years since 2018. Leptospirosis cases were reported throughout the year in China from 2010 to 2022, with the peak of incidence found during the period between August and October, and the peak of leptospirosis incidence varied in provinces. A higher number of leptospirosis cases was seen among men than among women, with a male to female ratio of 2.3:1, and the median age of leptospirosis cases was 50 years (interquartile range, 23 years), with the highest proportion of leptospirosis cases reported at ages of 51 to 60 years (23.21%). Among all reported leptospirosis cases, 53.28% were confirmed cases, and the proportion of confirmed cases increased from 35.05% in 2010 to 61.66% in 2022. In addition, there were 67.22% of leptospirosis cases (2 937 cases) reported by comprehensive hospitals, 20.44% (893 cases) by disease control and prevention institutions, 7.23% (316 cases) by grassroots healthcare institutions and 5.10% (223 cases) by other healthcare and medical institutions, and the mortality of reported leptospirosis cases was 1.07% in China from 2010 to 2022, with a higher mortality seen among men than among women (1.39% vs. 0.36%; χ² = 9.52, P = 0.002).

Conclusions: The incidence of leptospirosis remained at a low level in China from 2010 to 2022, and southern China was still the main endemic area for leptospirosis. The epidemiological characteristics of leptospirosis cases varied in endemic provinces, and leptospirosis cases had been continued to be reported in Shaanxi and Henan provinces, which should be paid much attention to. Intensified surveillance of leptospirosis, improved diagnosis and treatment capability of leptospirosis cases and leptospirosis control with adaptations to local circumstance are recommended.