Comparison of polymerase chain reaction and microscopy for the detection of Fasciola spp. in the fecal matter of domestic bovines in Kalasin Province, Thailand

Abstract

Background and Aim: Fasciola spp. are important foodborne trematodes and waterborne zoonotic parasites that cause health problems and economic losses worldwide, including in Thailand. Fasciola spp. are usually detected by sedimentation or the formalin-ethyl acetate concentration technique (FECT) under microscopy, which is less specific and sensitive. Accurate detection is important to detect real incidence for protection against and elimination of fasciolosis in the area. This study aimed to determine the distribution of Fasciola spp. and compare the specificity and sensitivity of FECT under microscopy to that of polymerase chain reaction (PCR) in cattle feces. Materials and Methods: The study was conducted in Kalasin Province, Thailand. Feces of 46 cattle were investigated for infection with Fasciola spp. To detect infection, FECT under microscopy and PCR amplification of the 28S rRNA gene of Fasciola spp. were used to identify egg parasites. Results: Feces of 16 of 46 (34.78%) cattle were positive for Fasciola spp. using FECT under microscopy, whereas PCR showed that 67.39% (31 of 46) were positive for Fasciola spp. False-negative results were as high as 32.61% when diagnosed under microscopy. Conclusion: This study confirmed the infection of cattle with Fasciola spp. in Kalasin Province, indicating that PCR demonstrated higher sensitivity and specificity when diagnosing infection. FECT under microscopy can still be used as a primary and traditional method for diagnosis. However, relapse cases of Fasciola spp. and Paramphistomum spp. should be diagnosed by microscopy combined with PCR. This is the first report on the molecular distribution of fecal samples in cattle in Kalasin Province.