[Infection due to Strongyloides stercoralis: epidemiological, clinical, diagnosis findings and outcome in 30 patients]

Abstract

Background: Strongyloides stercoralis is a nematode parasite, which is endemic in tropical and subtropical regions. Infection usually remains asymptomatic, but in immunocompromised hosts severe and life-threatening manifestations such as hyperinfection syndrome and disseminated disease might occur.

Methods: We retrospectively analyzed the epidemiological and clinical characteristics, including HIV co-infection, microbiological findings, and outcome in 30 patients with strongyloidiasis, who attended in the Infectious Diseases F. J. Muñiz Hospital in Buenos Aires from January 2004 to December 2008.

Results: The study included 20 men and 10 women with an average age of 33 years. HIV co-infection was present in 21 patients (70%) with a median CD4 T cell count of 50 cells/mm³ (range 7-355) (average 56 cells/mm³). Among HIV negative patients the following comorbidities were detected: tuberculosis (n = 3) and chronic alcoholism, leprosy treated with corticosteroids, immunosuppressive treatment for psoriasis, and diabetes mellitus (each in one patient). Two patients did not have any predisposing diseases or immunosuppressive treatments. Seventeen patients presented with diarrhea and were classified as chronic intestinal strongyloidiasis (57%), asymptomatic infection with peripheral eosinophilia was diagnosed in 7 (23%), and 6 patients (20%) developed hyperinfection syndrome. Seventeen patients (57%) presented peripheral eosinophilia. Diagnosis was achieved by direct visualization of larvae in feces by Baermann technique (n = 20), by multiple stool smears examinations (n = 2), by combination of both (n = 1), by visualization of the filariform larvae in duodenal fluid and stool (n = 1), and in fecal and bronchoalveolar lavage specimens (n = 6). Overall mortality in this series was 20% (6/30). There was no significant correlation between age and mortality. A significant inverse correlation between the survival rate and CD4 T-cell count as well as eosinophilia was observed. There was also a significant correlation between HIV co-infection and mortality. Twenty-two patients responded favorably to treatment with ivermectin.