Evaluation of Parasitological Methods for the Detection of Strongyloides Stercoralis among Individuals in Selected Health Institutions In Addis Ababa, Ethiopia

Abstract

BACKGROUND: Strongyloides stercoralis causes chronicintestinal infection that may lead to disseminated disease duringimmunosuppression. Therefore, efficient diagnostic methods areessential to detect silent and latent infections. The present studywas aimed to compare the efficacy of parasitological methods forthe detection of S. stercoralis infection.METHODS: A cross-sectional study was conducted on 351 subjects(226 HIV positive and 125 HIV negative) from October 2005 toMay 2006. The study participants were selected by systematicrandom sampling method. Fresh fecal samples were collected fromeach participant and processed by different parasitologicalmethods.RESULTS: Among the 351 individuals involved in the study,43(12.3%) were infected by S. stercoralis. The prevalence of S.stercoralis infection was significantly higher among HIV positivesubjects (17.3%) as compared with 3.2% in HIV negative subjects(p=0.001). The odd of being infected by S. stercoralis wassignificantly higher among AIDS patients (OR=6.31; 95% CI, 2.2-18.1) and HIV patients with diarrhea (OR=9.3; 95% CI 4.6-18.9)as compared with respective controls. Agar plate culture showedsuperior sensitivity (97.7%) than other methods for detection of S.stercoralis. Similarly, agar plate culture showed strong diagnosticagreement with Baermann’s method (kappa = 0.82; 95% CI 0.72 -0.92) followed by fecal concentration (kappa= 0.67; 95% CI=0.54-0.80).COCLUSION: This study revealed that HIV patients were about 6folds susceptible for S. stercoralis infection. Similarly, agar plateculture showed superior diagnostic efficiency for detections of S.stercoralis infection.