Abstract: Objective To understand the prevalence status of soil-transmitted nematode infection in population in Pingdingshan City for scientific evidence in prevention and control of this disease. Methods By the regulations specified in Surveillance Scheme of Soil-transmitted Nematode Disease in Henan Province,we conducted investigations in the four provincial mobile monitoring sites from 2016 to 2019,including Yexian County,Lushan County,Xinhua and Weidong Districts under the administration of Pingdingshan City. Each surveillance site was geographically zoned into five areas ( the east, west, south,north and center). Then one administrative village was selected from each town,where no less than 200 permanent residents aged over 3 years were annually included by cluster sampling,and totally no less than 1 000 people were included from each surveillance site. Fecal samples were collected from all subjects,and examined for infection of soil-transmitted nematodes using modified Kato-Katz thick smear technique( one sample for two smears) . Children aged between 3 and 9 years old were given additional detection of the eggs of pinworm sampled by anal cellophane swab. Results A total of 4 167 residents underwent examination from 2016 to 2019. The total infection rate was 0. 55%. The species infected in population consisted roundworm,hookworm and pinworm. The infection rate was 0. 19%,0. 10% and 0. 26%,respectively for each species,and the infection was generally mild( χ2 = 16. 952,P < 0. 05) . The infection rate of soil-derived nematodes was the highest in the people aged from 50 to 59(1. 34%). As far as the educational level was concerned,the highest infection rate was 1. 67% for illiterates( χ2 = 14. 557,P<0. 05)。 Among occupational population,the infection rate ranked from students (0. 83%),farmers(0. 71%) to employee of factory (0. 58%) ( χ2 = 10. 752,P<0. 05 ). Conclusion The infection rate of soil-transmitted nematodes tends to decrease in population in Pingdingshan City,nevertheless,comprehensive prevention and control efforts should be maintained,particularly in children in prevention and control of pinworm infection.

Key words: Soil-transmitted nematodes, Surveillance, Pingdingshan City