Seroprevalence of Babesia equi among horses in Israel using competitive inhibition ELISA and IFA assays.

This research focuses on analyzing the prevalence of antibodies for Babesia equi, a parasite that infects horses, in horse population of Israel. The testing was done by indirect immunofluorescence antibody test (IFA) and by competitive inhibition ELISA (cELISA), providing matching results in 95.7% of cases. A significant variance was noticed in the seroprevalence with different geographical regions, access to pasture, and horse gender.

Objective and Method

• The primary purpose of this study was to ascertain the seroprevalence or antibody prevalence of the disease-causing parasite Babesia equi, which invades the red-blood cells of horses, in the equine population of Israel.
• Researchers used two methods for the antibody detection – indirect immunofluorescence antibody test (IFA) and competitive inhibition enzyme-linked immunosorbent assay (cELISA). The IFA finds whether the antibodies are present; the cELISA determines how many antibodies are present.

Test Results and Findings

• Of the 361 horses’ serum samples examined, the results from both assays had a concordance of 95.7%. However, researchers needed to use a cutoff based on calculated percent inhibition to handle discrepancies.
• Around one-third of all horses tested showed the presence of antibodies to B. equi, showing exposure to the parasite at some point.
• The data also illustrated region-based outcomes, with a higher positive antibody prevalence found in northern Israel. Factors like access to pasture showed a significant impact on results, with pasture-raised horses indicating a higher seroprevalence.

Impact of Various Factors on Seroprevalence

• There were observable differences in seropositivity with horses with different pasture access. Horses raised with access to pasture had significantly higher percentages of seropositive reactors compared to the horses raised without access to pastures.
• The gender of the horses also significantly impacted the seroprevalence. Stallions were less likely to be seropositive compared to mares and geldings.
• Age, however, did not show a significant relationship with antibody prevalence for B. equi.

The implications of this research would be useful for some regions in Israel to implement measures to control the spread of Babesia equi among its horse populations, with more attention to horses with access to pastures and also considering the gender difference in seroprevalence.