Molecular characterization of Theileria equi infection in horse populations belonging to West Azerbaijan, Iran: insights into the importance of Equine Merozoite Antigen (EMA)-1 in its diagnosis.

The study focuses on the evaluation of Theileria equi infection, a major cause of equine piroplasmosis, in horse populations of West Azerbaijan. The research aims to provide insights into the diagnostic importance of Equine Merozoite Antigen (EMA)-1 and determine the prevalence of T. equi among local horses using molecular methods.

Methodology

• The researchers collected 126 blood samples from the horses’ jugular vein and preserved them in sterile tubes containing EDTA.
• Some tubes were used immediately for blood smears, while others were stored at -20°C for later examination using the polymerase chain reaction (PCR) method.

Findings

• When examining the samples, T. equi was detected in 3.2% of the animals using light microscopy, and 27.7% using PCR methods.
• Older animals (30.4%) demonstrated a higher prevalence of T. equi than young equines (24.6%).
• Female horses (31%) showed higher infection rates than the males (23.6%).
• Of the horses that were housed with other animals, 12 tested positive for T. equi. Meanwhile, 23 horses that were not housed with other animals were found to be infected.
• No significant difference was found between infection incidence and associated risk factors such as age, sex, and housing with other animals.

Implications

• The results suggest a high prevalence of T. equi in horses in West Azerbaijan.
• The study highlights the potential role of Equine Merozoite Antigen (EMA)-1 as a diagnostic tool for T. equi infection.
• Given the potential lifelong carrier state of animals with T. equi and its significant impact on the equine industry, accurate and early diagnosis of the disease is vital.
• A diagnosis could furnish critical information on the disease’s epidemiology, distribution, and prevalence, particularly in asymptomatic animals, aiding effective control and development of suitable vaccines.