Lateral Flow Dipstick Test for Serodiagnosis of Strongyloidiasis

Am J Trop Med Hyg. 2019 Aug;101(2):432-435. doi: 10.4269/ajtmh.19-0053.

Abstract

The conventional method of detecting Strongyloides stercoralis in fecal samples has poor diagnostic sensitivity. Detection of Strongyloides-specific antibodies increases the sensitivity; however, most tests are ELISAs that use parasite extract which may cross-react with the sera of other helminth infections. To improve the serological diagnosis of strongyloidiasis, this study aimed at developing a sensitive and specific lateral flow rapid dipstick test. Two recombinant proteins, recombinant NIE (rNIE) and recombinant Ss1a (rSs1a), were used in preparing the dipstick, with gold-conjugated antihuman IgG4 as detector reagent. In parallel, the corresponding ELISA was performed. Both assays demonstrated diagnostic sensitivity of 91.3% (21/23) when tested with serum samples of patients with Strongyloides infection, and 100% specificity with 82 sera of asymptomatic (healthy) and those with other parasitic infections. The ELISA and dipstick test results were positively correlated to each other (r = 0.6114, P = 0.0019). The developed lateral flow dipstick test may improve the serodiagnosis of strongyloidiasis and merit further validation studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antibodies, Helminth / blood*
  • Antigens, Helminth / immunology
  • Cross Reactions
  • Enzyme-Linked Immunosorbent Assay
  • Humans
  • Immunoglobulin G / blood
  • Recombinant Proteins / immunology
  • Sensitivity and Specificity
  • Serologic Tests / methods*
  • Strongyloides stercoralis
  • Strongyloidiasis / diagnosis*
  • Strongyloidiasis / immunology

Substances

  • Antibodies, Helminth
  • Antigens, Helminth
  • Immunoglobulin G
  • Recombinant Proteins