Development and evaluation of PCR methods based on cytochrome c oxidase subunit one (cox1) and NADH dehydrogenase subunit one gene (nad1) to detect Opisthorchis viverrini in human fecal samples

Opisthorchis viverrini is highly prevalent throughout Southeast Asia. Chronic infection of this parasite leads to cholangiocarcinoma (CCA), a fatal bile duct cancer. The early and accurate detection of this parasite is very important; therefore, new PCR methods targeting cytochrome c oxidase subunit one and NADH dehydrogenase subunit one gene to detect O. viverrini in fecal specimens have been developed. Ninety O. viverrini-positive human fecal samples were used in this study. The PCR sensitivity of both genes was compared with internal transcribe spacer 2 (ITS2)-PCR. The sensitivity of cox1-PCR and nad1-PCR was 66.7 and 50 %, respectively. The sensitivity of cox1-PCR and nad1-PCR achieved 89.1 and 71.7 % in specimens containing O. viverrini eggs of > 100 eggs per gram (EPG). Additionally, these primers can be used to provide the information on genetic diversity from mitochondrial genes of O. viverrini.