Investigation of prevalent status of soil-borne nematode in the Three Gorges Reservoir areas

Objective To understand the infection status of soil-borne nematode in the Three Gorges Reservoir areas and provide scientific evidence for the prevention and treatment of the disease. Methods 15 counties were selected in the Three Gorges Reservoir areas.The local populations of 4 villages from different directions were investigated by the same questionnaire. Stool samples were collected and examined by the Kato-Katz technique. The Enterobius vermicularis egg of children below 12 years old were examined by the adhesive cellophane anal swab method. Results Etiological examination was conducted for 30 820 people. The average infection rate of geohelminthes was 12.92%, with a range of 3.86%-24.90%. The infection rates of roundworm, whipworm, hookworm and oxyurid were 8.62%, 4.18%, 0.57% and 4.73%, respectively. The rate of roundworm infection was higher than other (χ2=2354.35,P0.01). There were significant differences of infection rates among counties (χ2=845.16,P0.01). The infection rates of the male and female were 12.82% and 13.02%, respectively, without any significant difference (χ2=0.59,P0.05). The general infection rate,roundworm infection rate and whipworm infection rate were the highest in 50 and 60 age group. There were significant difference of infection rates among different age groups (χ2=184.32,P0.01). The infection rates of preschool children (13.64%), farmers (13.29%) and students (11.61%) were higher than people of other occupations (χ2=41.23,P0.01). The infection rates of illiteracies (18.24%), primary school students (14.01%)and preschool children (13.64%) were higher than people of other educations (χ2=214.43, P0.01). The infection rate of hookworm increased with the increase in age(F=43.86,P0.01).Infection with single parasite was 91.50%. Conclusions The infection rate of soil-borne nematode decreased greatly when compared with that of the Second National Survey of Current Status of Major Human Parasitic Diseases in China in the Three Gorges Reservoir areas, but soil-borne nematode was still the principal endemic parasite. The infection rates of preschool children, primary school students and farmers were high. The roundworm was main soil-borne nematode parasite.