Epidemiology and factors associated with the infection of Babesia bigemina, Babesia bovis, and Theileria orientalis in Thale Noi Wetland buffaloes (Bubalus bubalis), Southern Thailand

Water buffaloes (Bubalus bubalis) play a critical role in maintaining biodiversity and supporting the local economy within the unique ecosystem of the Thale Noi Wetlands in Southern Thailand, a globally recognized heritage site. However, these buffaloes are commonly infected by hemoprotozoan parasites, which can lead to severe pathological conditions. This study aims to investigate the epidemiology of hemoprotozoan infections, assess the occurrence of co-infections among these pathogens, and identify the risk factors associated with infections in water buffalo. A total of 155 water buffaloes from 43 farms in the Thale Noi Wetlands were included in the study, and their blood samples were analyzed using PCR to detect the presence of Babesia bigemina, Babesia bovis, and Theileria orientalis. A phylogenetic analysis based on the T. orientalis gene encoding a major piroplasm surface protein was performed to assess genetic diversity. Additionally, questionnaire surveys were conducted on these farms. The associations between the presence of hemoprotozoan parasites and various risk factors were analyzed using logistic regression. Furthermore, Multiple Correspondence Analysis (MCA) was employed to explore the patterns and relationships among single and co-infections and associated factors. The prevalence of T. orientalis, B. bigemina, and B. bovis infections were 29.37%, 23.81%, and 5.6%, respectively, with triple infections accounting for 4.76%. The T. orientalis genotype N-1 was identified as the predominant genotype. The major risk factors for T. orientalis infection included poor body condition and younger buffaloes (1–5 years old). Male buffaloes had higher odds of B. bovis infection than female buffaloes. Additionally, the MCA identified significant clustering of single infections and co-infections, with T. orientalis and B. bigemina co-infection showing the strongest association and emerging as the most prevalent (25.39%). Younger buffaloes and those with poor body condition scores had higher odds of co-infections. This study reveals a high prevalence of hemoprotozoan infections among water buffaloes in the Thale Noi Wetland. Co-infection with T. orientalis and B. bigemina emerged as a significant finding. Additionally, the T. orientalis Type N-1 strain was identified as the predominant genotype, representing the first documented report of its presence in Southern Thailand. Younger age and poor body condition were key risk factors associated with infection. Addressing these factors through targeted interventions may enhance buffalo health and productivity within this ecologically important ecosystem.