[HTML][HTML] Diagnostic Accuracy of Five Serologic Tests for Strongyloides stercoralis Infection

Z Bisoffi, D Buonfrate, M Sequi, R Mejia… - PLoS neglected …, 2014 - journals.plos.org
Z Bisoffi, D Buonfrate, M Sequi, R Mejia, RO Cimino, AJ Krolewiecki, M Albonico, M Gobbo
PLoS neglected tropical diseases, 2014journals.plos.org
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 …
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. NIE-LIPS 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.
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