[Incidence of leptospirosis in Fujian province, 2015-2020]

Objective: To analyze the incidence of leptospirosis in Fujian province from 2015 to 2020 and provide the scientific evidences for the risk assessment, prevention and control of leptospirosis. Methods: The incidence data of leptospirosis in Fujian during 2015-2020 were collected from China Information System for Disease Control and Prevention for a descriptive analysis, and software ArcGIS 10.3.1 was used for spatial autocorrelation analysis, and rats were captured in 17 surveillance areas during the same period, and the rat organs were collected for pathogen culture, the level of Leptospira antibody was detected in serum samples of rats, healthy population and the serum samples of patients sent by the hospitals. The infection status of Leptospira in human and rats were analyzed. Results: The incidence of leptospirosis in Fujian showed a downward trend from 2015 to 2020. A total of 176 cases of leptospirosis were reported. There were obvious seasonality and bimodal distribution. The majority of cases were farmers, accounting for 49.43% (87/176). Most cases were aged 30-69 years (85.80%, 151/176). The male to female ratio of the cases was 3.51∶1 (137∶39). Spatial autocorrelation analysis showed that leptospirosis had high or low clustering areas. From 2015 to 2020, the average capture rate of rats in 17 surveillance areas was 6.96% (1 519/21 838), Rattus losea, Rattus flavipectus and Niviventer fulvescens were the main species. The average positive rate of Leptospira antibody in rats was 28.64% (252/880). Java and Autumnalis were the predominant serogroups, accounting for 56.75% (143/252) and 17.46% (44/252), respectively. The average positive rate of Leptospira antibody in healthy population was 16.13% (254/1 575), and Autumnalis and Australis were the predominant serogroups, accounting for 71.65% (182/254). The confirmation rate of leptospirosis in patient serum samples sent by the hospitals was 2.23% (188/8 431), Autumnalis (56.38%, 106/188) and Hebdomadis (19.68%, 37/188) were the major serogroups. Conclusions: The incidence of leptospirosis in Fujian showed a downward trend from 2015 to 2020, there were obvious area clustering and seasonality. The high clustering areas were mainly distributed in northern, western and central Fujian. Java and Autumnalis were the predominant serogroups in rats. The infection rate in healthy population decreased year by year. Autumnalis and Hebdomadis were the main serogroups in population in Fujian.