Ikeda et al. [70] showed that an ELISA using the natural CP purified from P. westermani ESP as antigens not only had higher sensitivity to patients’ sera with paragonimiasis westermani than using the total antigens extracted from adult worms, but also had reduced cross-reactivity with sera with fascioliasis, onchocerciasis, or clonorchiasis to negligible levels. This evidence concerns the gene CP and paragonimiasis.