Evaluation of Strongyloides stercoralis infection in HTLV-1 patients

Abstract

Introduction: Individuals infected with the human T-lymphotropic virus type 1 (HTLV-1) may present severe and disseminated forms of Strongyloides stercoralis (S. stercoralis) infection with low therapeutic response. Objective: To investigate the S. stercoralis infection and the seroprevalence of IgG anti-S. stercoralis antibodies in individuals infected with HTLV-1, who were seen at a Reference Center for HTLV-1 (CHTLV), in Salvador, Bahia, Brazil. Materials and methods: This was a cross-sectional study conducted with 178 HTLV-1-infected individuals, treated at the HTLV specialized center between January 2014 and December 2018. The parasitological diagnosis of S. stercoralis was performed using the Hoffman, Pons and Janer, agar plate culture and Baermann-Morais methods. The IgG anti-S. stercoralis detection was performed by an in house Enzyme Lynked-Immunosorbent Assay (ELISA). The HTLV-1 infection was diagnosed using a commercial ELISA and confirmed by Western blot. Results: The frequency of S. stercoralis infection was 3.4% (6/178). Moreover, individuals infected with S. stercoralis from rural area (50.0%; 3/6), also showed S. stercoralis hyperinfection (> 3,000 larvae/gram of feces). The frequency of circulating anti-S. stercoralis IgG antibodies was 20.8% (37/178). Conclusions: HTLV-1-infected people living in precarious sanitary conditions are more prone to develop severe forms of S. stercoralis infection. Considering the high susceptibility and unfavorable outcome of the infection in these individuals, the serological diagnosis for S. stercoralis should be considered when providing treatment.