Risk factors for acquiring Strongyloides stercoralis infection among patients attending a tertiary hospital in south India

Abstract

Purpose: Strongyloides stercoralis causes persistent and fatal disseminated infections in immunocompromised hosts. In this study, we aimed to determine the risk factors for acquiring strongyloidiasis and the associated morbidity in south India.

Materials and methods: The study was carried out in two parts. This included a 6-month chart review of cases with strongyloidiasis and randomly selected controls conducted to determine the association with immunocompromised states. Secondly, a cross-sectional study was conducted to investigate hyperinfection in human immunodeficiency virus (HIV)-infected adults where the stool and sputum samples were examined by microscopy for Strongyloides larvae.

Results: In the chart review, 118 cases were compared with 240 controls. A higher proportion of patients on corticosteroids [8 (53.3%)] and with HIV infection [3 (60%)] had the risk of acquiring strongyloidiasis than not, although the difference was not statistically significant in this population. In the cross-sectional study, 14/239 HIV-positive individuals had Strongyloides larvae in the stool samples but none had Strongyloides detectable in their sputum samples. The CD4 cell counts were significantly lower in cases with Strongyloides compared with HIV-infected individuals with no parasites in their stool samples (P < 0.001).

Conclusions: In this setting, strongyloidiasis was seen more often in patients on corticosteroid therapy and with HIV infection. In HIV, an association with lower CD4 counts indicates the need for inclusion of Strongyloides as an opportunistic parasite. Gram negative sepsis was an important complication of strongyloidiasis hyperinfection in both HIV and steroid therapy. Further prospective studies on the risk of developing complicated Strongyloides infection are required.