Diagnostic Accuracy of Five Serologic Tests for Strongyloides stercoralis Infection

BISOFFI Z; BUONFRATE D; SEQUI M; MEJIA R; CIMINO R; KROLEWIECKI A; ALBONICO M; GOBBO M; BONAFINI S; ANGHEBEN A; REQUENA-MENDEZ A; MUÑOZ J; NUTMAN TB

PLOS NEGLECTED TROPICAL DISEASES

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2014 vol. 8 p. 1 - 8

1935-2735

Background: The diagnosis of Strongyloides stercoralis (S. stercoralis) infection is hampered by the suboptimal sensitivity of fecal-based tests. Serological methods are believed to be more sensitive, although assessing their accuracy is difficult because of the lack of sensitivity of a fecal-based reference (??gold??) standard. Methods: The sensitivity and specificity of 5 serologic tests for S. stercoralis (in-house IFAT, NIE-ELISA and NIE-LIPS and the commercially available Bordier-ELISA and IVD-ELISA) were assessed on 399 cryopreserved serum samples. Accuracy was measured using fecal results as the primary reference standard, but also using a composite reference standard (based on a combination of tests). Results: According to the latter standard, the most sensitive test was IFAT, with 94.6% sensitivity (91.2?96.9), followed by IVD-ELISA (92.3%, 87.7?96.9). The most specific test was NIE-LIPS, with specificity 99.6% (98.9?100), followed by IVD-ELISA (97.4%, 95.5?99.3). NIE-LIPS did not cross-react with any of the specimens from subjects with other parasitic infections. NIELIPS and the two commercial ELISAs approach 100% specificity at a cut off level that maintains $70% sensitivity. Conclusions: NIE-LIPS is the most accurate serologic test for the diagnosis of S. stercoralis infection. IFAT and each of the ELISA tests are sufficiently accurate, above a given cut off, for diagnosis, prevalence studies and inclusion in clinical trials.