Objective: To understand the infection status and the main risk factors of soil-transmitted nematodes in children in the poverty-stricken areas of Guizhou Province and Sichuan Province, so as to provide the evidences for making suitable control strategies in these areas.
Methods: A total of 95 villages and 6 primary schools in 6 poor counties in the two provinces were selected as investigation sites according to the stratified random sampling method. Eleven preschool children aged 3-5 years in each sample village and 11 school children aged 8-10 years in each sample school were chose as investigation objectives, their feces were collected and examined by Kato-Katz technique. In addition, the village doctor and cadres in each village were investigated by a standardized questionnaire to understand the deworming condition of children and the social economy and sanitary status in 2009. Then the correlation between average soil-transmitted nematode infection rate and its influencing factors was analyzed by the Tobit model.
Results: A total of 1 707 children from 95 villages in the two provinces were examined. In Guizhou Province, the total infection rate of soil-transmitted nematodes in children was 46.1%, and the infection rates of Ascaris lumbricoides, Hookworm, and Trichuris trichiura were 31.1%, 4.1% and 10.8% respectively, and the corresponding rates in Sichuan Provinces were 9.8%, 3.6%, 3.5%, 2.7%, respectively. In the dimension of school, a total of 890 school-aged kids from 46 schools in the two provinces were examined, the infection rates of soil-transmitted nematodes, Ascaris lumbricoides, Hookworm, and Trichuris trichiura in Guizhou Province were 53.8%, 32.7%, 6.6% and 14.4%, respectively, and the corresponding rates in Sichuan Province were 7.3%, 2.2%, 2.9% and 2.2%, respectively. The results from Tobit analysis indicated that the proportion of children accepted deworming treatment and the paddy field in the cultivated area were statistically correlated to the infections of soil-transmitted nematodes and Ascaris lumbricoides (all P < 0.05).
Conclusions: The soil-transmitted nematode infection rates of children are still at a high level in poor areas of southwest China. In order to decrease the infection rates, besides the long-term deworming, water supply and sanitary improvement, and the health education should be strengthened, and the treatment of soil-transmitted nematodes should be covered by the New Rural Cooperative Medical System.