Detection of a carcinogenic liver fluke among migrant workers by three coprological concentration methods

Opisthorchis viverrini is a major health problem in many part of Southeast Asia. Therefore, this study aimed to detect Opisthorchis viverrini infection among migrant workers in Thailand by using three coprological concentration methods. A cross-sectional study was conducted among 147 migrant workers in Thailand. Fecal samples were processed by the modified formalin ether concentration technique, the Kato Katz thick smear, and the miniparasep solvent free parasite fecal concentrator. Specificities, sensitivities, negative predictive values, positive predictive values, Kappa indexes were analyzed with SPSS version 22. The infection rate with opisthorchiasis was 27.2%. The parameters measured for the modified formalin ether concentration technique, Kato Katz thick smear, and mini-parasep solvent free parasite fecal concentrator methods respectively were as follows: infection rates (23.1%, 12.9%, and 22.4%), sensitivities (85.0%, 47.5%, and 82.5%), specificities (100%, 100%, and 100%), positive predictive values (100%, 100%, and 100%), and negative predictive values (94.7%, 83.6%, and 93.9%). The kappa index value of diagnostic agreement between formalin ether concentration technique and mini-parasep solvent free parasite fecal concentrator showed substantial agreement for O. viverrini. In conclusion, the calculated analytical sensitivity, and negative predictive values indicate that modified formalin ether concentration technique and mini-parasep solvent free parasite fecal concentrator are more accurate in detecting O. viverrini infections. The study indicates that the mini-parasep solvent free parasite fecal concentrator method was the method with high potential to be used in routine laboratory and community diagnosis for opisthorchiasis.