Analysis on the epidemioiogical situation of soil-transmitted nematode infections at monitoring spots from 2006 to 2009

Objective To understand and analyze the epidemiological situation of soil-transmitted nematode infections at monitoring spots.Methods The stool samples of the residents at 22 monitoring spots were collected and examined for Ascaris lumbricoides.Trichuris trichiura and hookworms with modified KatoKatz thick smearone stool specimen-three slidesfrom September to November from 2006 to 2009,and additional adhesive cellophane anal swab method was applied for examining the eggs of Enterobius vermicularis in children aged 3～12.other parasite species detected were registered as well.Soil samples were collected for microscopic examination on fertilized or unfertilized ascaris eggs,and identification of live and dead fertilized ascaris eggs at each monitoring spot.Results The total of 90 957 persons from 22 monitoring spots were investigated from 2006 to 2009,the yearly infection rates of soil-trapsmitted nematode were 20.9%,18.9%,16.6%and 13.3%respectively,showing a declined tendency.The infection rate of soil-transmitted nematode was higher in the females than that in the males.Children were still the high risk population for soil-transmitted nematode infection.The yearly infection rates of A.lumbricoides were 10.1%,8.9%,7.4%and 6.4%.The yearly infection rates of T. trichiura were 5.9%,5.7%,6.6%and 5.2%.The yearly infection rates of hookworlns were 8.9%,9.0%,6.8%and 5.8%from 2006 to 2009.While the yearly infection rates of Enterobius vermicularis were 10.0%,10.0%,7.4%and 7.0%respectively in children aged 3-12 from 2006 to 2009.The result of soil samplirig survey showed that the detection rates of ascaris eggs in the soil were 37.1%,29.5%,25.9%and 31.3%,indicating persistent contamination of ascaris eggs in the soil.Conclusion According to the 4 years monitoring,the infection rate of soil-transmitted nematodes was declined year by year,but the infection rate of soil-transmitted nematodes was still high in some highly epidemic areas.It is necessary to continue monitoring in the areas. Key words: Soil-transmitted nematode disease; Monitoring spot; Monitoring situation