Seroprevalence and Molecular Analysis of Babesia caballi and Theileria equi in Horses From Central Italy During a 10-Year Period

The aim of the present article was to retrospectively analyze serologic data about Babesia caballi and Theileria equi infection in horses from Central Italy in a 10-year period. In addition, part of sera samples was examined by polymerase chain reaction (PCR) to evaluate the concordance between the two tests. A total of 1,441 serum specimens were examined. Each sample was examined by immune fluorescent antibody test (IFAT) for both B. caballi and T. equi, starting from 1/80 dilution. During 2012, blood samples (n, 117) were also checked by PCR. Differences in the prevalence values between T. equi and B. caballi were evaluated by means of chi square. Agreement between IFAT and PCR results was calculated by Cohen kappa. Five hundred of 1,441 horses tested seropositive for piroplasms. Differences in prevalence values between T. equi and B. caballi were statistically significant (P < .001). Fifty-six of 117 sera examined in 2012, scored positive to at least one test; IFAT results showed 38 of 117 sera positive to T. equi, whereas PCR results scored positive for 48 of 117. B. caballi was detected neither by IFAT nor PCR. Cohen kappa index was 0.599 indicating a moderate agreement. Prevalence values observed are consistent with data available from literature in which an extremely wide range is reported. The low and occasional occurrence of antibodies against B. caballi is in line with some studies and has been confirmed by PCR. The agreement between IFAT and PCR found is moderate allowing us to recommend the utility of performing both tests to achieve a correct diagnosis.