[Spatio-temporal distribution characteristics of soil-transmitted nematodiasis in Sichuan Province from 2016 to 2021]

To investigate the trends in the prevalence of soil-transmitted nematode infections and the spatio-temporal distribution characteristics of soil-transmitted nematodiasis in Sichuan Province from 2016 to 2021, so as to provide the evidence for formulating the soil-transmitted nematodiasis elimination strategy in Sichuan Province.

The soil-transmitted nematodiasis surveillance data in Sichuan Province from 2016 to 2021 were collected, and the epidemic trend of soil-transmitted nematode infections was identified. The distribution maps of soil-transmitted nematode infections in Sichuan Province were plotted to identify their spatial distribution characteristics. In addition, the spatial clusters of soil-transmitted nematode infections were detected using globa and local spatial autocorrelation analyses.

The prevalence of soil-transmitted nematode infections appeared a decline with time in Sichuan Province from 2016 to 2021 (χ²= 400.24, P < 0.01). Global spatial autocorrelation analysis identified positive spatial autocorrelations in the prevalence of soil-transmitted nematode infections (Moran's I = 0.322, Z = 16.293, P < 0.01), hookworm infections (Moran's I = 0.425, Z = 21.290, P < 0.01), Ascaris lumbricoides infections (Moran's I = 0.102, Z = 5.782, P < 0.01) and Trichuris trichiura infections (Moran's I = 0.084, Z = 6.873, P < 0.01). Local spatial autocorrelation analysis showed that the high-high clusters of soil-transmitted nematode infections were mainly located in 37 counties (cities, districts) of Sichuan Province, and the high-high clusters of hookworm, A. lumbricoides and T. trichiura infections were mainly identified in 39 counties (cities, districts) in mountainous areas around Sichuan Basin and hilly areas, 9 counties (cities, districts) in mountainous areas in southwestern Sichuan Province, and 8 counties (cities, districts) in mountainous areas in southwestern Sichuan Province, respectively.

The prevalence of soil-transmitted nematode infections appeared a tendency towards a decline in Sichuan Province from 2016 to 2021, which showed spatial clusters. The management of soil-transmitted nematodiasis requires to be reinforced in high-risk areas of Sichuan Province with adaptations to local epidemiological features.