Equine piroplasmosis in different geographical areas in France: Prevalence heterogeneity of asymptomatic carriers and low genetic diversity of Theileria equi and Babesia caballi.

This study investigates the prevalence of Equine piroplasmosis, a disease caused by two types of parasites Theileria equi and Babesia caballi, among asymptomatic carriers in different regions in France. The researchers found that the prevalence varies by region, and that one type of parasite is far more common than the other, with implications for disease control and prevention efforts.

Overview of Equine Piroplasmosis and the Study

• The study focuses on Equine piroplasmosis, a globally spread tick-borne disease mostly affecting horses. It is caused by the parasites named Theileria equi sensu lato and Babesia caballi.
• This disease significantly costs both economy and health. The parasites are genetically variable, which may possibly affect the accuracy of diagnosis.
• In the course of the research, the team aimed to quantify the autosomal carriers, those animals who harbor the parasite but show no outward symptoms, residing in France. They also attempted to identify the existing genotypes of the parasites.

Research Methodology

• The researchers used a certain nested PCR protocol, specifically for each species. This targeted the 18S small sub-unit (SSU) rRNA gene.
• The team ran blood tests drawn from 566 asymptomatic horses from four veterinary schools throughout the nation.

Findings and Conclusions

• The frequency of carriers fluctuated across different areas, from 18.7% in the central-north around Paris to 56.1% in the southeast around Lyon. Overall prevalence account to 38.3%.
• Theileria equi carriers were found in higher number than B. caballi carriers, the former being ten times more common than the latter.
• The band of T. equi carriers was notably lesser in the northern region as compared to southeastern regions.
• No significant correlation found between the horse’s gender or age and the frequency of asymptomatic carriers. However, a large chunk of horses around 22.2% to 37.5 % were carriers of T. equi before turning three years old, suggesting high pressure from infection.
• Upon genotyping, it was revealed that out of 201 T. equi isolates, most of them belonged to genotype E and only a few to genotype A. Moreover, all 19 B. caballi isolates fell under the genotype A category.

Implications and Further Discussion

• The researchers discuss that the findings may also have an association with the distribution and abundance of ticks, and the frequency of detection of T. equi and B. caballi, in cases of fever caused by piroplasmosis.
• This study provides necessary inputs regarding the prevalence, geographical distribution, and genotypic variation of the parasites causing Equine piroplasmosis in France and few horses from Spain as well. This might aid in better diagnostic, prevention, and control strategies for the disease.