Prevalence of Trichuris trichiura in relation to socio-economic & behavioural determinants of exposure to infection in rural Assam

Background & objectives : Stunting, anaemia, and the poor level of mental d evelopment are known to be associated with Trichuris trichiura infections. However, no information is available on the socio-environmental predictors relevant to Trichuris infection in rural communities. Whilst geohelminthic infections pe, sc is an inevitable consequence of poor personal hygiene and household sanitation, the importance of specific factors in the epidemiolo gy of Trichuris infection have not been formally investigated. The objectiv e of this study was to explore, quantify and study different socio-environm ental risk factors and find out their possible interaction vis-a-vis T: tri chiura infection. Methods : The study population consisted of 244 children (aged 15 yr and be low) and 336 adults selected from 144 randomly selected households belongin g to three villages of upper Assam. The prevalence rate ratio (PRR; = relat ive risk) and 95 per cent confidence interval (CI) were calculated. Univari ate, multivariate analysis using Cox's proportional hazards regression assu ming constant risk period and a tree-based risk factor analysis, were used. Results : In the overall multivariate model, open field defaecation,large f amily size, and three or more children in the household were found independ ently associated with Trichuris infection. Gender specific analysis reveale d that in females the age was also independently associated with increased risk of infection whereas in males, earth flooring was the most significant risk factor independently associated with the risk of Trichuris infection. Tree-based risk factor analysis indicated interaction between defaecating habits of people and the source of drinking water. Interpretation & conclusions : Installation of pit latrines (if not sanitar y latrines) together with provision for safe drinking water and the constru ction of cement floors would probably reduce community prevalence of T. tri chiura effectively.