Strongyloides stercoralis in an urban slum community in Bangladesh: factors independently associated with infection

Stool samples from 880 residents in an urban slum in Dhaka, Bangladesh, were collected on 3 occasions over one year, and examined for intestinal parasites. Information on many potential risk factors for infection was obtained by questionnaire from a respondent in each household studied. In a crude univariate analysis of the data, several of the factors were found to be significantly associated with Strongyloides stercoralis infection. Most of these factors were co-variate with one another, and with poverty generally. Using Mantel-Haenszel chi 2 tests to control for confounding effects of each variable individually, the following 4 factors remained independently associated with S. stercoralis infection: respondent's use of a community latrine rather than a private latrine, living in a house with an earth floor rather than a cement floor, being of Bihari ethnicity, and being 7-10 years of age. Implications of these results for the epidemiology and control of strongyloidiasis are briefly discussed.