Diagnostic methods for intestinal parasites in southern Iraq with reference to Strongyloides stercoralis

Three hundred and thirty-two stool samples were examined for the presence of intestinal parasites including Strongyloides stercoralis. Each sample was processed and examined by direct smear, formalin-ether and Harada and Mori culture methods. Nine parasites were recovered from patients attending Basrah Teaching Hospital, southern Iraq during 1989. The prevalence rate of infection was 64.2%. It was higher in rural (74.2%) than in urban (57.5%) region (p < 0.01). Sex distribution was 120 (36.1%) males and 87 (26.2%) females (p > 0.05). The most common parasites were Blastocystis hominis, Giardia lamblia, Entamoeba histolytica, Hymenolepis nana and Strongyloides stercoralis. Formalin-ether concentration method was 3.75 times better than the direct smear method in the diagnosis of helminth rather than protozoan infections. The yield obtained by the usage of the Harada and Mori culture method (4.5%) was significantly higher than that obtained by formalin-ether (2.7%) or direct smear (0.3%) methods. Therefore, the Harada and Mori culture method is recommended in patients with undiagnosed diarrhea and where strongyloidiasis is endemic or suspected. Investigation of the relationship between age of the patients and prevalence showed that the prevalence of total intestinal parasites and of Strongyloides alone had essentially levelled off by age 11-20 and 21-30 years old, respectively. Clinical symptoms associated with S. stercoralis infection were diarrhea, anorexia and abdominal pain. Thiabendazole is still a drug of choice in the treatment of strongyloidiasis.