Analysis on the epidemiological situation of soil-transmitted nematode infections at the monitoring spot of Chongqing from 2006 to 2010

Objective To understand infection status and epidemic law of soil-transmitted nematode infections in Chongqing.Methods The stool samples of the residents at monitoring spot of Chongqing were collected and examined for Ascaris lumbricoides,Trichuris trichiura and hookworms with modified Kato-Katz thick smear one stool specimen-three slides from September to November during 2006-2010,and adhesive cellophane anal swab method was applied additionally for examining the eggs of Enterobius vermicularis in children aged 3-12.Ten soil samples were collected for microscopic examination on fertilized or unfertilized Ascaris eggs and the living ability of fertilized Ascaris eggs was determined.Results The total of 5 071 persons were investigated from 2006 to 2010 and the annual infection rates were 5.79％,13.52％,16.63％,8.62％and 2.81％ showing a declined tendency (x2=3.65,P ＜ 0.01).The infection rates of females were higher than males in 2007 and 2008 (x2=4.66,P ＜ 0.05;x2 =25.29,P ＜ 0.01).The infection rate of 5-year-old was in the highest level in 2006 and 2010.In 2010 the infection rate of 50-year-old was in the highest level.The ancylostomiasis and Ascaris were the major soil transmitted nematode diseases.The infection rates of Enterobius vermicularis were not significantly different between boys and girls.It showed a declined tendency in pinworm infection in girls(x2=16.36,P ＜ 0.01)while it showed no difference in boys(x2=8.45,P ＞ 0.05).The positive rates of Ascaris eggs in soil samples were 52.5％,37.5％,17.5％,30.0％ and 20.0％ showing a declined tendency (x2 =16.36,P ＜ 0.01).Conclusion According to the 5 years monitoring,the infection rate of soil-transmitted nematodes was declined,but health education and mass chemotherapy should be enhanced continuously. Key words: Nematode infection ;  Soil-transmitted nematode disease ;  Monitoring spot ;  Analysis