Strongyloidiasis in a high risk community of Dhaka, Bangladesh

Residents of a slum community of Dhaka city, Bangladesh were tested by serological and faecal examination for evidence of Strongyloides stercoralis infection. In stool specimens from a total of 147 participants Strongyloides larvae were found in 34 (23.1%) by Harada-Mori culture, 15 (10.2%) by agar plate culture (APC) and one (0.7%) by microscopy. Strongyloides IgG, IgG1 and IgG4 antibodies were found in 90 (61.2%), 46 (31.3%) and 53 (36.1%) of participants, respectively. A positive correlation was observed between total IgG levels and the presence of isotypes IgG1 and IgG4 (p<0.001). Six sera (4.0%) reacted to the recombinant filaria antigen Bm 14, three of which were Strongyloides IgG positive. This indicates either there is cross reactivity or some participants are co-infected with lymphatic filariasis. No correlations were found between positive serology and Strongyloides infection in stool, socio- demographic factors or domestic hygienic practices. However, positive stool cultures showed significant associations with irregular nail trimming, walking bare-foot and irregular hand washing after defecation (p<0.05). Other enteric parasites were detected in stools of some participants but their presence showed no correlation with S. stercoralis infection or socio demographic factors. This study confirms that squatters in this slum community in Dhaka have a high prevalence of S. stercoralis infection identified both by serological and coprological methods.