Study Of The Influence Of Environmental Sanitation And Related Behavioral Factors On Ascaris Infection Of Rural Pupils

Objectives:Through the survey of the rural pupils of Zunyi county in Guizhou province, the study aims to find out the Ascaris infection of pupils in rural areas and the current environmental status in schools and houses where the pupils live; to investigate and analyze the health behavior and environmental risk factors of the pupils' Ascaris infection in rural areas. Provide the reference data for making preventing and controlling strategy of Ascaris infection for pupils in rural areas.Methods:Pupils of Grade four and Grade five in 10 primary schools of 5 rural townships in Zunyi county were selected for the study of detecting bellyworm eggs in the pupils' excreta by KATO-KATZ according to different geographical location and economic status. In the investigation of school influencing factors, pupils whose excreted eggs detection were positive were in the positive group, and else in the negative group.In the investigation of family and behavioral influencing factors, the pupils whose excreted eggs detection were positive were in the positive group, and according to about 1:1 proportion to choose the pupils in the same school and same grade whose excreted eggs were negative in the negative group for household survey with unified survey questionnaires. The possession and utilization status of sanitation facilities of schools and families, the parents' health knowledge and behavior were all collected through enquiry and interview on the spot. Meanwhile, the data on water sample and soil sample in schools and a part of families were collected. The logistic regression model was used to analyze the single factors and multivariate analysis was used during stepwise regression for statistically significant variables in single factor analysis process. The statistics software SPSS 15.0 was used to analyze the data collected.Results:1. This study has conducted investigation in ten primary schools in rural areas of Zunyi county, collecting 943 students'excreta samples. The total Ascaris infection rate was 27.68% and the rate of slight infection was 88.12%. In the family investigation,529 effective questionnaires were collected,255 in positive group and 274 in negative group, the male to female ratio in positive group and negative group were consistent.2. In the study,30 soil samples of 10 schools and 9 water samples of 9 schools were collected. No worm egg was detected in all of the water samples, and worm eggs were detected in 14 soil samples. For the families factors,230 soil samples were collected and 26.96% were detected with worm eggs; 57 water samples were collected and 21.05% were detected with worm eggs. The water samples detected with worm eggs were all in water stored in tanks.3. In 3 of the 10 rural primary schools, water supplies were inadequate. Four schools had water storage facilities, but only one has disinfection measures. Only 1 school latrine was biogas latrine, and the latrines in other 9 schools were all non-sanitary ones. The garbage of all the schools was to be piled up in fixed place and collected uniformly. Sewage in two schools only was discharged after disposal. In the 529 households surveyed, the main type of water supply is tap water which are provided by the villages and towns, accounting for 67.10% of the total.86.20% of the water supply can satisfy their daily uses.7.37% of the families didn't have latrine; of those with latrines, the coverage rate of sanitary latrine was 24.08%. The household sanitation status of the households was not as good as expected. The rates of randomly piled garbage and randomly discharged sewage were 33.89% and 27.41% respectively.4. Among the 943 surveyed pupils, only 9.76% knew that Ascariasis was transmitted through dirty hand, food and drinking water. For the healthy behaviors, the rate of never drinking unboiled water was 45.49%, and the rate of washing hands before meals and after defecating was 76.25% and 78.79% respectively. The rate of washing hands with soap was 60.66%. Among the 529 surveyed patents, only 21.76 % knew that Ascariasis was transmitted through dirty hand, food and drinking water. For the healthy behaviors,81.29% usually wash fruits and vegetables before direct eating.49.15% never drink unboiled water. The rates of washing hands before meals and after defecating were 65.60% and 65.78% respectively.51.42% of the parents usually washed hands with soap, and 78.07% of the parents answered they never doing farmwork barefoot.5. In the school influencing factors, the univariate logistic regression analysis showed that whether the canteen can supply normal washing facilities, types of the latrines, the exposure of faeces were influencing factors of the pupils' Ascaris infection. Bring the above factors into multivariate analysis, the result showed the types of latrines were related with pupils'Ascaris infection. In the family and behavioral factors, the univariate analysis showed there were 20 statistically significant factors influencing rural pupils'Ascaris infection between the positive group and negative group. They were educational degree of father, annual family income, main sources of the family income, the washing of water containers, hand washing facilities, the disposal of garbage, the types of latrines, sanitation status of courtyard, living room and kitchen, drinking unboiled water, washing hands before meals and after defecating, whether washing hands with soap, parents' habit of drinking unboiled water, washing fruits and vegetables before eating, parents washing hands before meals and after defecating, washing hands with soap and whether doing farmwork barefoot. After considering the collinearity of the variables bring them into multivariate logistic regression analysis, the results showed the types of latrines, the washing of water containers, the habit of parents drinking unboiled water, main sources of the family income, household hand washing facilities, washing fruits and vegetables before eating and the pupils'habits of washing hands after defecating all had statistically significant relationship with pupils'Ascaris infection, OR and its 95% CI were 2.313 (1.348-3.968),1.996 (1.028-3.877),1.918 (1.340-2.745),1.811 (1.044-3.143),1.771 (1.072-2.924),0.556 (0.332-0.931),0.350 (0.217-0.564) respectively。Conclusion:1. Ascaris infection of pupils in Zunyi county were serious, but most of them were slight infection.2. The soil in schools and households and the water in water container at home were contaminated with worm eggs. The total conditions of environmental sanitation in schools and households were not so good.3.In the school influencing factors, the types of latrines was related with pupils' Ascaris infection.4. In the family factors, the types of latrines, the washing of water containers, household hand washing facilities, main sources of the family income were influencing factors of pupils' Ascaris infection.5. In the behavioral factors, washing hands after defecating of the pupils, the habit of parents drinking unboiled water and the families washing fruits and vegetables before eating were influencing factors of pupils' Ascaris infection.6. The risk levels of influencing factors from high to low were the use of non-sanitary latrine in schools and houses, not usually washing water container, parents drinking unboiled water, farming as the main source of the family income, using common wash-basin for hands washing at home. Usually washing fruits and vegetables at home before eating and washing hands after defecating of the pupils were the protecting factors for pupils' Ascaris infection. Controlling of these factors may prevent pupils'Ascaris infection effectively.