Abstract:

Objective To investigate the trends in the prevalence of soil-transmitted nematode infections in Shaanxi Province from 2016 to 2023, so as to provide insights into formulation of the soil-transmitted nematodiasis control strategy. Methods According to the requirements of the National Clonorchiasis and Soil-transmitted Nematodiasis Surveillance Program (Trial), surveillance sites were sampled from counties (districts) in Shaanxi Province each year from 2016 to 2023, and each surveillance site was divided into 5 areas according to geographical locations, including eastern, western, southern, northern and central areas. One administrative village was sampled from each area, and at least 200 residents were surveyed in each administrative village, with at least 1 000 residents were surveyed in each surveillance county. Participants’ fecal samples were collected, and the soil-transmitted nematode eggs were detected using the Kato-Katz technique (two slides of one stool sample). The prevalence of soil-transmitted nematode infections was compared with Chi-square test. Results A total of 76 surveillance sites were assigned in Shaanxi Province from 2016 to 2023. The overall prevalence of soil-transmitted nematode infections was 0.13% (115/90 790) among participants, and only Ascaris lumbricoides infection was detected. The prevalence rates of soil-transmitted nematode infections were 0.70% (63/9 040), 0.20% (18/9 073), 0.17% (15/9 013), 0.07% (6/9 076), 0 (0/9 334), 0 (0/9 061), 0.06% (10/17 122) and 0.02% (3/19 071) in Shaanxi Province from 2016 to 2023, respectively (χ² = 161.424, P < 0.01). The highest prevalence of soil-transmitted nematode infections was detected in Tongchuan City (0.27%, 11/4 042) (χ² = 110.412, P < 0.01) and Fenwei basin ecological zone (0.17%, 67/39 105) (χ² = 18.581, P < 0.01). In addition, the highest prevalence of soil-transmitted nematode infections was found among residents at ages of 20 to 29 years (0.21%, 13/6 071), participants with an occupation of preschool children (0.21%, 16/7 758) and participants with an educational level of preschool children (0.21%, 16/7 770), and there were significant differences in the prevalence of soil-transmitted nematode infections among participants in terms of age groups, occupations and educational levels (χ² = 13.245, 11.243, 16.737, all P < 0.05). Conclusion The prevalence of soil-transmitted nematode infections was at a low level in Shaanxi Province from 2016 to 2023, with A. lumbricoides as the predominant parasite species. The prevalence of human soil-transmitted nematode infections varies greatly in different regions and populations.

Key words: Soil-transmitted nematode, Epidemiological characteristics, Shaanxi Province