Epidemiology of strongyloidiasis determined by parasite-specific IgG detections by enzyme-linked immunosorbent assay on urine samples using Strongyloides stercoralis, S. ratti and recombinant protein (NIE) as antigens in Northeast Thailand

Chatanun Eamudomkarn; Sirowan Ruantip; Jiraporn Sithithaworn; Anchalee Techasen; Kulthida Y Kopoolrat; Chanika Worasith; Phattharaphon Wongphutorn; Jeffrey M Bethony; Thewarach Laha; Paiboon Sithithaworn

doi:10.1371/journal.pone.0284305

Epidemiology of strongyloidiasis determined by parasite-specific IgG detections by enzyme-linked immunosorbent assay on urine samples using Strongyloides stercoralis, S. ratti and recombinant protein (NIE) as antigens in Northeast Thailand

PLoS One. 2023 Apr 12;18(4):e0284305. doi: 10.1371/journal.pone.0284305. eCollection 2023.

Authors

Chatanun Eamudomkarn^{1

2}, Sirowan Ruantip^{3

4}, Jiraporn Sithithaworn⁵, Anchalee Techasen^{2

5}, Kulthida Y Kopoolrat^{2

6}, Chanika Worasith^{1

2}, Phattharaphon Wongphutorn^{2

3}, Jeffrey M Bethony⁷, Thewarach Laha¹, Paiboon Sithithaworn^{1

2}

Affiliations

¹ Department of Parasitology, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
² Cholangiocarcinoma Research Institute (CARI), Khon Kaen University, Khon Kaen, Thailand.
³ Biomedical Science Program, Graduate School, Khon Kaen University, Khon Kaen, Thailand.
⁴ Wireless and Intelligent System for Dual-Use Applications Research Division (WISRD), National Science and Technology Development Agency (NSTDA), Pathum Thani, Thailand.
⁵ Faculty of Associate Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
⁶ Faculty of Public Health, Kasetsart University Chalermphrakiat Sakon Nakhon Province Campus, Sakon Nakhon, Thailand.
⁷ Department of Microbiology, Immunology & Tropical Medicine, George Washington University, Washington, DC, United States of America.

Abstract

Detection of anti-Strongyloides IgG in urine by enzyme-linked immunosorbent assay (ELISA) for diagnosis of strongyloidiasis reportedly has comparable performance to conventional serum assays. Initial comparisons of urine assays using commercial ELISA kits designated for serology have shown its diagnostic potential but sub-optimal accuracy. In the present study, we optimized urine ELISA protocols based on different antigen types and evaluated their accuracies in determining the epidemiology of strongyloidiasis in Northeast Thailand. Paired urine and fecal samples of 966 individuals from the study community were collected for three consecutive days and tested for strongyloidiasis. We compared three ELISA protocols using different antigens including crude S. stercoralis antigen (Ss-ELISA), crude S. ratti antigen (Sr-ELISA) and recombinant NIE antigen (NIE-ELISA) and fecal examination by agar plate-culture (APCT) technique and formalin-ethyl acetate concentration technique (FECT). The optimized ELISA protocols using three different antigen sources yielded significantly higher prevalence rates of strongyloidiasis (58.9-65.1%) than those by fecal examination methods (19.7%). The prevalence of strongyloidiasis determined by ELISA protocols significantly increased with age (p value < 0.0001) and males had higher prevalence than females (p value < 0.0001). Diagnostic agreements between ELISA protocols were moderate (κ = 0.461-0.586) and the agreement between each ELISA protocol and fecal examinations were slight (κ = 0.139-0.210). The results obtained by urine ELISA protocols using three different antigens showed comparable diagnostic performances, provided further supports for the utility of urine as an alternative clinical specimen for diagnosis of strongyloidiasis.

Copyright: © 2023 Eamudomkarn et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antibodies, Helminth
Antigens, Helminth
Enzyme-Linked Immunosorbent Assay / methods
Feces
Female
Humans
Immunoglobulin G
Male
Parasites*
Recombinant Proteins
Sensitivity and Specificity
Strongyloides stercoralis*
Strongyloidiasis* / diagnosis
Strongyloidiasis* / epidemiology
Thailand / epidemiology

Substances

Antibodies, Helminth
Antigens, Helminth
Recombinant Proteins
Immunoglobulin G

Grants and funding

This work described here was supported by the Faculty of Medicine, Khon Kaen University, Thailand (Grant Number IN60242) to CE. SR is supported by the Royal Golden Jubilee Ph.D. Program (grant no. PHD/0017/2557). The contents are solely the responsibility of the authors and do not necessarily represent the official views of the Royal Golden Jubilee Ph.D. Program. The work described here was partly supported by the Cholangiocarcinoma Research Institute, Khon Kaen University, and Fluke-Free Thailand, National Research Council of Thailand. PS is supported by National Science, Research and Innovation Fund (NSRF) under the Basic Research Fund of Khon Kaen University through Cholangiocarcinoma Research Institute (CARI-BRF64-50). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.