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 development 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 per se is an inevitable consequence of poor personal hygiene and household sanitation, the importance of specific factors in the epidemiology of Trichuris infection have not been formally investigated. The objective of this study was to explore, quantify and study different socio-environmental risk factors and find out their possible interaction vis-a-vis T. trichiura infection.

METHODS

The study population consisted of 244 children (aged 15 yr and below) and 336 adults selected from 144 randomly selected households belonging to three villages of upper Assam. The prevalence rate ratio (PRR; = relative risk) and 95 per cent confidence interval (CI) were calculated. Univariate, multivariate analysis using Cox's proportional hazards regression assuming constant risk period and a tree-based risk factor analysis, were used.

RESULTS

In the overall multivariate model, open field defaecation, large family size, and three or more children in the household were found independently associated with Trichuris infection. Gender specific analysis revealed 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 sanitary latrines) together with provision for safe drinking water and the construction of cement floors would probably reduce community prevalence of T. trichiura effectively.