Potential of antibody test using Schistosoma mansoni recombinant serpin and RP26 to detect light-intensity infections in endemic areas

Schistosomiasis remains a worldwide public health problem, especially in sub-Saharan Africa. The World Health Organization targets the goal for its elimination as a public health problem in the 2030 Neglected Tropical Diseases (NTDs) Roadmap. Concerted action and agile responses to challenges will be necessary to achieve the targets. Better diagnostic tests can accelerate progress towards the elimination by monitoring disease trends and evaluating the effectiveness of interventions; however, current examinations such as Kato–Katz technique are of limited power to detect light-intensity infections. The point-of-care circulating cathodic antigen (POC-CCA) test shows a higher sensitivity compared to the reference standard, Kato-Katz technique, but it still lacks sufficient sensitivity with low infection intensity. In this study, we examined antibody reactions against recombinant protein antigens; Schistosoma mansoni serine protease-inhibitor (SmSerpin) and RP26, by enzyme-linked immunosorbent assay (ELISA) in plasma samples with light-intensity infection. The sensitivity using the cocktail antigen of recombinant SmSerpin and RP26 showed 83.7%. The sensitivity using S. mansoni soluble egg antigen (SmSEA) was 90.8%, but it showed poor specificity (29.7%), while the cocktail antigen presented improved specificity (61.4%). We conclude that antibody detection to the SmSerpin and RP26 protein antigens is effective to detect S. mansoni light-intensity infections. Our study indicates the potential of detecting antibody against recombinant protein antigens to monitor the transmission of schistosomiasis in low endemicity contexts.
長崎大学学位論文 学位記番号:博(医歯薬)甲第1356号 学位授与年月日:令和3年6月2日
Author: Mio Tanaka, Anna O. Kildemoes, Evans Asena Chadeka, Benard Ngetich Cheruiyot, Miho Sassa, Taeko Moriyasu, Risa Nakamura, Mihoko Kikuchi, Yoshito Fujii, Claudia J. de Dood, Paul L.A.M. Corstjens, Satoshi Kaneko, Haruhiko Maruyama, Sammy M. Njenga, Remco de Vrueh, Cornelis H. Hokke, Shinjiro Hamano
Citation: Parasitology International, 83, art.102346; 2021