Surveillance of soil-transmitted nematode infection at a national surveillance spot in Shandong Province from 2006 to 2010

Objective To understand the infection status and related factors of soil-transmitted nematodes at the national surveillance spot of Shangdong Province,and provide the scientific evidence for making the control policy.Methods Kato-Katz thick smears was applied for examining the eggs of Ascaris lumbricoides,Trichuris trichiura and hookworms in fecal samples collected among local residents,additionally,the adhesive cellophane anal swab method was used for detecting Enterobius vermicularis in children aged 3-12.Results A total of 5076 people received the examination from 2006 to 2010.The average infection rate of soil-transmitted nematodes was reduced from 27.9％ in 2006 to 7.2％ in 2010,decreased by 74.19％.The rate showed an annual decline trend by Chi-square test (x2 =189.530,P ＜ 0.01).The average infection rates of ascaris and whipworm were 2.8％ and 14.2％ respectively,and the rates showed a decline trend from 2006 to 2010 (x2a =33.448,x2w =160.528,P ＜ 0.01).The cases of hookworm were only 1 or 2 every year,and there was no statistical difference.The age group of above 50 or under 20 had the highest infection rate,and the rate showed a increasing trend with the age increase (x2 =111.458,P ＜ 0.01).The occupation with highest prevalence was peasant,followed by students and preschool children as second (x2 =77.175,P ＜0.01).The infection rate of pinworm in children aged between 3 and 12 years decreased to 2.2％ in 2010,showing a decline trend during this period (x2 =11.856,P ＜ 0.05).Conclusion The infection rate of soil-transmitted nematodes at the national surveillance spot in Shandong declined from 2006 to 2010.The key population for the control is the old people,children and peasants. Key words: Nematode infection; Soil-transmitted nematodes; Infection rate; Surveillance