Development of an Immunochromatographic Point-of-Care Test for Serodiagnosis of Opisthorchiasis and Clonorchiasis

Abstract

Chronic infections with the food-borne liver flukes, Opisthorchis viverrini or Clonorchis sinensis, associate with cholangiocarcinoma, bile duct cancer, which generally has a poor prognosis. We have produced a rapid and simple immunochromatographic test (ICT) kit for the diagnosis of opisthorchiasis and clonorchiasis by the detection of IgG antibodies in human infection sera. Sera from volunteers with proven opisthorchiasis and several other parasitic diseases and from healthy controls were evaluated for the presence of liver fluke infection-specific antibodies using a preparation of excretory-secretory antigen from adult stage O. viverrini absorbed onto ICT strips. Diagnostic values were compared with an ELISA. The diagnostic sensitivity, specificity, and positive and negative predictive values of the ELISA were 100%, 98.3%, 97.9%, and 100%, whereas those for the ICT were 94.6%, 91.2%, 89.7%, and 95.4%, respectively. There was 91.7% concordance between the ICT with ELISA, and differences in performance between the tests were not statistically significant (P > 0.05). Twenty-seven of 30 (90%) of the clonorchiasis sera also were positive by ICT. This new ICT provides a facile, rapid test for point-of-care testing tool, which can be used at the bedside without the need for sophisticated equipment. Moreover, the ICT can be anticipated to supplement stool examination as a screening tool in the clinic for the diagnosis of opisthorchiasis and clonorchiasis, and in addition, it may be useful in screens of populations at risk of liver fluke infection-associated cholangiocarcinoma.

Figure 1.

The immunochromatographic device for the diagnosis of opisthorchiasis and clonorchiais. (A) An example of a positive result on the immunochromatographic test (ICT) strip (left) and a negative result (right). (B) The interpretation card to adjudicate the ICT signal. This figure appears in color at www.ajtmh.org.

Figure 2.

Representative results obtained with the immunochromatographic test kit. Ac = angiostrongyliasis; Al = ascariasis; Bh = blastocystosis; Cp = capillariasis; Cc = cysticercosis; Cs1–Cs14 = clonorchiasis; Gl = giardiasis; Gs = gnathostomiasis; Hw = hookworm infection; N = negative control; Ov1–Ov12 = opisthorchiasis; P = positive control; Ph = paragonimiasis heterotremus; Sp = sparganosis; Ss = strongyloidiasis; Ta = taeniasis saginata; Ts = trichinellosis; Tt = trichuriasis. This figure appears in color at www.ajtmh.org.