Comparative assessment of the SjSAP4-incorporated gold immunochromatographic assay for the diagnosis of human schistosomiasis japonica

Yi Mu; Jonas Rivera; Donald P McManus; Kosala G Weerakoon; Allen G Ross; Remigio M Olveda; Catherine A Gordon; Hong You; Malcolm K Jones; Pengfei Cai

doi:10.3389/fpubh.2023.1249637

Comparative assessment of the SjSAP4-incorporated gold immunochromatographic assay for the diagnosis of human schistosomiasis japonica

Front Public Health. 2023 Sep 1:11:1249637. doi: 10.3389/fpubh.2023.1249637. eCollection 2023.

Authors

Yi Mu¹, Jonas Rivera^{1

2}, Donald P McManus¹, Kosala G Weerakoon¹, Allen G Ross³, Remigio M Olveda⁴, Catherine A Gordon^{1

5}, Hong You^{1

6}, Malcolm K Jones^{1

6}, Pengfei Cai^{1

2}

Affiliations

¹ Molecular Parasitology Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, QLD, Australia.
² School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, Australia.
³ Rural Health and Medical Research Institute, Charles Sturt University, Orange, NSW, Australia.
⁴ Department of Immunology, Research Institute for Tropical Medicine, Manila, Philippines.
⁵ School of Public Health, Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia.
⁶ School of Veterinary Science, The University of Queensland, Brisbane, QLD, Australia.

Abstract

Background: Schistosomiasis, a disease caused by parasites of the genus Schistosoma, remains a global public health threat. This study aimed to validate the diagnostic performance of a recently developed gold immunochromatographic assay (GICA) for the detection of S. japonicum infection in a rural endemic area of the Philippines.

Methods: Human clinical samples were collected from 412 subjects living in Laoang and Palapag municipalities, Northern Samar, the Philippines. The presence of Schistosoma-specific antibodies in serum samples was tested with the SjSAP4-incorporated GICA strips and the results were converted to fully quantitative data by introducing an R value. The performance of the established GICA was further compared with other diagnostic tools, including the Kato-Katz (KK) technique, point-of-care circulating cathodic antigen (POC-CCA), droplet digital (dd) PCR, and enzyme-linked immunosorbent assays (ELISAs).

Results: The developed GICA strip was able to detect KK positive individuals with a sensitivity of 83.3% and absolute specificity. When calibrated with the highly sensitive faecal ddPCR assay, the immunochromatographic assay displayed an accuracy of 60.7%. Globally, the GICA assay showed a high concordance with the SjSAP4-ELISA assay. The schistosomiasis positivity rate determined by the GICA test was similar to those obtained with the SjSAP4-ELISA assay and the ddPCR assay performed on serum samples (SR_ddPCR), and was 2.3 times higher than obtained with the KK method.

Conclusion: The study further confirms that the developed GICA is a valuable diagnostic tool for detecting light S. japonicum infections and implies that this point-of-care assay is a viable solution for surveying endemic areas of low-intensity schistosomiasis and identifying high-priority endemic areas for targeted interventions.

Keywords: ASSURED criteria; POC-CCA; Schistosoma japonicum; SjSAP4; diagnosis; droplet digital PCR; gold immunochromatographic assay (GICA); schistosomiasis.

Publication types

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

MeSH terms

Enzyme-Linked Immunosorbent Assay
Feces
Gold
Humans
Immunoassay
Schistosomiasis japonica* / diagnosis

Substances

Gold