Diagnostic tools for human opisthorchaisis

ABSTRACT

Liver flukes of the family Opisthorchiidae consist of three medically important species, namelyClonorchissinensis, Opisthorchis felineus and Opisthorchis viverrini.These liver flukes infect at least 40 million people andestimated 700 million people worldwide are at risk of being infected. Of the three currently recognized species, only O. viverrini is classified as a type 1 carcinogen because of its role as an initiator of chronic inflammation leadingto subsequent development of cholangiocarcinoma (CCA). At present, there is no early diagnosis of CCA,the patients usually come to the doctor with advanced stages and die within 3 - 6 months. Importantly, this speciesof liver fluke is most commonly found in Southeast Asia. Especially, an estimated 9 million people are infectedin Thailand, that the cost of treatment of opisthorchiasis is approximately $120 million dollars annually for lostwages and medical care. High accuracy and sensitivity diagnostic methods are therefore required for efficientcontrol, prevention and treatment of opisthorchiasis. To date, there are three main methods for opisthorchiasisdiagnosis, i.e. parasitological method, which is standard method for microscopy-based identification of diagnosisstage such as egg in fecal sample. However, its sensitivity and specificity are low due to limitations of skilland expert of distinguishing egg morphology. Thus, immunological methods and molecular methods to identifythe opisthorchiasis were developed to improve sensitivity and specificity of diagnostic tools. This review articleaims to compile all opisthorchiasis diagnostic methods in order to obtain the suitable guideline for the effectivediagnosis of opisthorchiasis.