Opisthorchis viverrini infection among migrant workers in Nakhon Ratchasima province, Thailand, indicates continued need for active surveillance.

Opisthorchis viverrini is a serious problem in Thailand, Cambodia, the Lao People's Democratic Republic and Vietnam. Active surveillance and eradication of O. viverrini is required. A cross-sectional study of 403 immigrant workers was conducted between October 2016 and June 2017 in Nakhon Ratchasima, Thailand. Stool samples were analysed via the formalin-ether concentration technique, with subsequent data analysis performed using descriptive statistics and logistic regression. Overall infection was 24.1% and the results reveals an O. viverrini infection rate was 11.9%. O. viverrini infection was identified in 25.6% of Cambodians, 15.3% of Laotians and 3.6% workers from Myanmar sampled. The majority of infections were found in males, aged e"40 years and working as labourers. Raw or undercooked cyprinoid fish consumption was associated with an elevated risk for O. viverrini infection (ORadj = 2.2, 95% CI = 1.2-4.0). Other intestinal helminthic infections were hookworm (5.5%), Trichuris trichiura (5.2%), Strongyloid stercoralis (0.5%), Ascaris lumbricoides (0.5%) and Taenia spp. (0.5%), respectively. This is the first study to report O. viverrini among immigrant workers in Thailand; therefore, active surveillance is needed among migrant workers to identify and treat O. viverrini infection.

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.