Transmission and diagnosis of equine babesiosis in South Africa.

The paper studies the transmission and prevalence of equine babesiosis in South Africa, identifies a new tick vector for the disease, explores accurate diagnostic methods, and emphasizes the importance of identifying infected horses for export purposes.

Understanding Equine Babesiosis

• Equine babesiosis is a protozoal tick-borne disease affecting horses.
• The organisms responsible are Babesia equi and B. caballi.
• The study investigates the transmission, prevalence, diagnosis and management of this disease in South Africa.

New Vector for B. equi

• A new vector for B. equi, the tick Rhipicephalus evertsi mimeticus commonly found in Namibia, was identified in the study.
• However, the R. turanicus tick, previously thought to transmit the disease, failed to transmit both B. equi and B. caballi under laboratory conditions.

Challenges in Diagnosing Babesia Caballi

• B. caballi presents challenge to diagnosis, due to its low-level presence in infected horses which makes it hard to detect in typical blood smear tests.
• As a result, B. caballi’s role as a pathogen is not fully understood.

Importance of Identifying Infected Horses

• The research stresses on the importance of diagnosing infected horses, especially those intended for export to Babesia-free countries, in order to prevent new outbreaks.

Disease Prevalence and Diagnostic Techniques

• A number of techniques are used to study disease prevalence including thick and thin blood smears, serology (Indirect Fluorescent Antibody Test – IFAT), and DNA probes.
• Among the 293 healthy, adult, thoroughbred horses screened, B. equi was detected in 4.4%, 70.6%, 13% and B. caballi was found in 0.7%, 37%, 18.4% using the respective methods.

Efficiency of Diagnostic Methods

• While DNA probes showed a higher sensitivity than blood test in detecting carrier infections, they may not be enough to identify all carrier infections.
• A low correlation was found between detection of parasites’ DNA and seropositivity, suggesting that these two methods may not always align in detecting infection.
• However, the potential of polymerase chain reaction (PCR) to amplify the parasite’s DNA from a sample is highlighted in the study and could improve diagnosis accuracy.