Diagnosis and prevalence of Theileria equi horses in western Mexico by nested PCR.

The research used nested polymerase chain reaction (nPCR) to investigate the prevalence of Theileria equi infection among horses in western Mexico, revealing a prevalence of approximately 19.7% with higher prevalence in adult horses, certain breeds, and stabled horses.

Methodology

• The study started off by obtaining 1000 blood samples from what appeared to be healthy horses in Western Mexico.
• The samples were then sent over to the Animal Biotechnology Laboratory at the University of Guadalajara for the diagnosis of Theileria equi, a blood parasite that can cause disease in horses.
• The technique used to detect the pathogen was nested polymerase chain reaction (nPCR), a highly sensitive method of amplifying and detecting small amounts of DNA.
• To ensure they were targeting Theileria equi DNA in the samples, they used primers for the merozoite antigen-1 (EMA-1) gene, which is specific to T. equi.

Findings

• The study revealed a T. equi infection prevalence of about 19.7% in the horses, with a 95% confidence interval range of 17.23-22.17%.
• An analysis of the data showed that gender had no significant association with T.equi infection.
• However, the prevalence of T. equi was higher amongst stabled horses (25.81%) compared to those left in open spaces for grazing (15.02%).
• Differences in prevalence between breeds also became apparent, with the rate being higher among certain breeds like the Quarter Horse (24.70%), Lusitano (35.90%), and Costa Rican Saddle Horse (47.37%) as compared to seven other breeds also investigated in the study.
• Furthermore, the prevalence of T. equi infection was higher in adult horses (age four years and above) at 25.05%, compared to colts and fillies (2-4 years old, 15.48%), yearlings (1-2 years old, 10.49%), and foals (less than 1 year old, 10.34%).

Significance

• This study was the first of its kind to comprehensively investigate T. equi infection prevalence among horses in Mexico using the nPCR method.
• The find indicates that equine piroplasmosis, a potentially debilitating disease caused by T. equi, is enzootic, meaning it is regularly found among animals in this specific area of Western Mexico.
• The outcomes of the research can be helpful for regions with similar horse-rearing practices to implement preventive measures against equine piroplasmosis.