J M Warnecke
EUROIMMUN AG, Germany
Title: Sensitive and specifi c ELISA for the serological diagnosis of strongyloides infections
Biography
Biography: J M Warnecke
Abstract
Introduction: The nematode Strongyloides stercoralis is the causative agent of strongyloidiasis, which can manifest in humans with dermatological, pulmonal and intestinal symptoms frequently passing into a chronic disease. As stool-based microscopy and culture techniques lack sensitivity, the detection of serum antibodies is regarded as a surrogate for diagnosing Strongyloides infections. Here, we evaluated the analytical performance of a novel anti-Strongyloides IgG ELISA.
Methods: The Anti-Strongyloides ELISA IgG (Euroimmun AG, Lübeck, Germany) is based on antigen prepared from S. papillosus. ELISA sensitivity and specifi city were evaluated in comparison to the serological reference standard applied at the Institute for Parasitology, University of Bern, Switzerland. Th e sensitivity panel comprised 17 anti-Strongyloides antibody positive sera according to the reference in-house ELISA. The specifi city/cross-reactivity panel included 39 control sera classifi ed as negative for anti-Strongyloides antibodies or positive for antibodies against other parasites, including samples from patients with other parasitic infections (Echinococcus, Filaria, Ascaris, Toxocara, Trichinella, Fasciola, Schistosoma, Trichuris, Amoeba, Leishmania, Plasmodium, multi-infection; n=25), cancer patients (n=5) and healthy blood donors (n=9). Borderline results were considered as positive.
Results: Th e results obtained using the Anti-Strongyloides ELISA were in agreement with reference testing in 94.6% (53/56) of all samples. In the sensitivity panel, the Anti-Strongyloides ELISA was positive in 16/17 sera, corresponding to a sensitivity of 94.1%. The serum yielding discrepant results was collected from a patient with multiple infections. Among the control samples, positivity was found in 2/39 cases (one cancer patient and one blood donor), resulting in a specifi city of 94.9%.