Molecular prevalence of Toxoplasma gondii and Trypanosoma evansi in recently calved female cattle from Phayao, Thailand

Background and Aim: Toxoplasma gondii and Trypanosoma evansi, the zoonotic protozoa responsible for toxoplasmosis and trypanosomiasis, are significant threats to the productivity and financial stability of livestock farming. T. gondii can be transmitted horizontally through ingestion of fecal oocysts and T. evansi through arthropod vectors. In addition, both species can be transmitted from mother to fetus through the placenta. This study aimed to assess the molecular prevalence of T. gondii and T. evansi transplacental-transmitted protozoans and to identify the epidemiological risk factors in recently calved female cattle across Phayao, Thailand. Materials and Methods: We collected 106 bovine placentas from beef and dairy cow full-term pregnancies in Phayao, Thailand. T. gondii and T. evansi DNA were detected using targeted B1 gene and expression site-associated gene (ESAG) species-specific polymerase chain reaction (PCR), respectively. Results: Forty-three placentas were positive for T. gondii B1 PCR, whereas only one was positive for T. evansi ESAG PCR, resulting in an overall prevalence of transplacental-transmitted protozoan infection of 41.5% (44/106). The prevalence of T. gondii and T. evansi was 40.6% (43/106) and 0.9% (1/106), respectively. No significant correlation was found between T. gondii infection and various risk factors, including locality, age, and cattle type. Conclusion: The prevalence of transplacental-transmitted protozoan T. gondii infection was high among female cattle in Phayao, Thailand, whereas the prevalence of T. evansi infection was notably lower. Although the conventional modes of transmission differ between these two parasites, the transplacental transmission of T. evansi and especially T. gondii may play a crucial role in the persistence of these protozoan species in this area. Keywords: bovine placenta, Toxoplasma gondii, transplacental transmission, transplacental-transmitted protozoan, Trypanosoma evansi.