This proposal addresses the significant public health threat posed by the liver flukes Clonorchis sinensis and Opisthorchis viverrini in at-risk human populations including personnel stationed in Southeast Asia for military or government service in previous decades. Infection with the two liver flukes is associated with a greater risk for cholangiocarcinoma, a highly lethal cancer of the bile ducts. Clonorchiasis and Opisthorchiasis affect over 35 million people worldwide, principally in East and Southeast Asia. As liver fluke infection can persist up to several decades, military service personnel, immigrants and travelers returning from these areas may be at risk for cholangiocarcinoma due to an active or past infection. This project addresses the lack of readily available tests for liver fluke infection in the U.S. through development of screening and point-of-care assays. Phase II will focus on completing development of ELISA and lateral flow (LF) tests, clinical studies for evaluation of test performance, manufacturing scale-up, validation of the ELISA as a CLIA laboratory test, and regulatory submissions for FDA clearance, CE mark, and distribution in Southeast Asia. The ELISA and lateral flow tests will be the first validated tests for Clonorchiasis and Opisthorchiasis to be developed and made commercially available in the U.S.