Development of a latex microsphere-based lateral flow immunoassay for the diagnosis of schistosomiasis japonica

Emmanuel John Tabilin; Catherine A Gordon; Yi Mu; Mario Jiz; Marianette Inobaya; Eleonor Avenido-Cervantes; Darren Gray; Mary Lorraine Mationg; Donald P McManus; Thomas G Egwang; Moses Adriko; Yasuhito Sako; Marcello Otake Sato; Megumi Sato; Hong You; Matthew Kelly; Pengfei Cai

doi:10.1371/journal.pntd.0012742

Development of a latex microsphere-based lateral flow immunoassay for the diagnosis of schistosomiasis japonica

PLoS Negl Trop Dis. 2024 Dec 16;18(12):e0012742. doi: 10.1371/journal.pntd.0012742. Online ahead of print.

Authors

Emmanuel John Tabilin^{1

2}, Catherine A Gordon^{1

2}, Yi Mu¹, Mario Jiz³, Marianette Inobaya³, Eleonor Avenido-Cervantes³, Darren Gray⁴, Mary Lorraine Mationg^{3

5}, Donald P McManus¹, Thomas G Egwang⁶, Moses Adriko⁷, Yasuhito Sako⁸, Marcello Otake Sato⁹, Megumi Sato¹⁰, Hong You¹, Matthew Kelly⁵, Pengfei Cai^{1

11}

Affiliations

¹ Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
² Faculty of Medicine, The University of Queensland, Brisbane, Queensland, Australia.
³ Research Institute for Tropical Medicine, Department of Health, Manila, Philippines.
⁴ Population Health Program, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia.
⁵ Department of Applied Epidemiology, National Centre for Epidemiology and Population Health, Australian National University, Canberra, Australian Capital Territory, Australia.
⁶ Department of Immunology and Parasitology, Med Biotech Laboratories, Kampala, Uganda.
⁷ Vector Borne & Neglected Tropical Disease Control Division, Ministry of Health, Kampala, Uganda.
⁸ Asahikawa Medical University, Asahikawa, Japan.
⁹ Faculty of Medical Technology, Division of Global Environment Parasitology, Niigata University of Pharmacy and Medical and Life Sciences, Niigata, Japan.
¹⁰ Graduate School of Health Sciences, Niigata University, Niigata, Japan.
¹¹ School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia.

Abstract

Background: Zoonotic schistosomiasis, caused by Schistosoma japonicum, is prevalent in China, the Philippines and Indonesia. Rapid point-of-care (POC) diagnostics are attractive and promising tools for evaluating the efficacy of intervention strategies for schistosomiasis control.

Methodology: The diagnostic potential of five recombinant antigens was tested by enzyme-linked immunosorbent assay (ELISA) using sera from individuals with positive Kato-Katz (KK) results for S. japonicum (n = 28) and non-endemic controls (n = 12). A latex microsphere (LM)-based lateral flow immunoassay (LFIA) incorporating the recombinant SjSAP4 (rSjSAP4) was developed for the diagnosis of schistosomiasis japonica. The test conditions including diluent, dilution factor and reaction time, were optimised for the developed LFIA. Under the optimised conditions, serum samples from individuals living in a barangay endemic for S. japonicum (n = 549) and non-endemic controls (n = 50) were tested with the established LFIA cassettes. The results were imaged by a smartphone and analysed by the ImageJ program. The intensity ratio of the test line to the control line (T/C ratio) was calculated for each cassette.

Main findings: ELISA confirmed that rSjSAP4 was the optimal candidate for serological diagnosis of schistosomiasis japonica. Under optimal testing conditions, the developed LFIA strips had a sensitivity of 80.6% and a specificity of 98.0% at a cut-off T/C ratio of 0.1031. Moreover, the results of the LM-based LFIA was positively correlated with those obtained from the rSjSAP4-ELISA (r = 0.8270, 95% CI, 0.7990-0.8514; p < 0.0001). The schistosomiasis prevalence determined by the LFIA strips was about 1.8 times greater than that obtained with the 6-slide KK procedure performed on three stool samples.

Conclusions/significance: The developed LFIA represents a POC diagnostic tool that is suitable for onsite screening of human S. japonicum infection with minimal equipment needed. The established immunochromatographic assay complies with most of the WHO's ASSURED criteria for POC diagnostics.

Copyright: © 2024 Tabilin 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.

Grants and funding

This work was supported by an e-ASIA Joint Research Program with grants from the National Health and Medical Research Council (NHMRC) of Australia (APP2008433 to PC), the Philippine Council for Health Research and Development (Grant No. FP 220025 to MJ) and the Japan Agency for Medical Research and Development (Grant No. JP21jm0210091 to YS). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.