Prevalence of Strongyloides stercoralis and Other Intestinal Parasites among Institutionalized Mentally Disabled Individuals in Rasht, Northern Iran

Background: We aimed to determine the status of strongyloidiasis in mentally disabled population in the institutional places in Rasht City, the capital of Guilan Province, northern Iran. Methods: This cross-sectional study was conducted in 8 institutions for mentally retarded population in Rasht in 2013. Before collecting the samples, a questionnaire was filled out for each participant by an expert person. A single stool sample was obtained from each of the 173 subjects and examined using direct wet mount, formalin-ether concentration technique and agar plate culture method. Results: A total of 173 mentally disabled individuals aged 2-57 (25.69+/-11.56) yr old were studied. Stool examination showed that 51 (29.5%) cases were infected with at least one parasite. Of 173 studied cases only 10 (5.8%) individuals were infected with pathogenic parasites, of which 2 (1.2%) cases were infected with Strongyloides stercoralis and 8 (4.6%) with Giardia lamblia. On the other hand, 42 (24.3%) of the studied population were infected with non-pathogenic intestinal protozoa such as Blastocystis hominis (n=29, 16.8%), Entamoeba coli (n=16, 9.2%) and Endolimax nana (n=4, 2.3%). Mixed protozoal infections were observed in 8 (4.6%) individuals. Conclusion: The prevalence rate of S. stercoralis in mentally disabled individuals in Rasht was somewhat higher than those of normal population of the province. The same picture was seen when the prevalence of G. lamblia and non-pathogenic protozoa in normal and mentally disabled populations were compared.