OCCURANCE OF ANTIBODIES AGAINST ENCEPHALITOZOON CUNICULI IN HORSES IN AUSTRIA

Introduction Infections with the microsporidian Encephalitozoon cuniculi occur in a wide range of mammalian and avian hosts. The development of clinical disease in different hosts is strongly influenced by natural innate species-specific susceptibility and the immune status of the individual. Infection in animals is usually subclinical but abortion, encephalitis and colic in horses have been described. Less is known about the infection rate of E. cuniculi in horses in general, and in Austria data is completely lacking. Therefore, this study was conducted to fill the data gap on the current seroprevalence of the pathogen in the Austrian horse population. Methods Clinically healthy horses were convenience sampled by veterinarians throughout Austria after public announcement of a study on infectious diseases in the Austrian horse population. Throughout Austria 588 horses were sampled. An in-house indirect immunofluorescence antibody test (IFA) was used to detect serum antibodies against E. cuniculi with a cut-off of 1:40. Results Of 588 tested horses, 211 (35.9%; CI95%=32.0-39.8) had an antibody titer against E. cuniculi of 1:40 or more, with maximum titers of up to 1:2560. The seropositive horses were located all over Austria. Conclusion Due to the unexpectedly high prevalence rates of antibodies against E. cuniculi, further studies are needed to address the seropositive horse population, especially with relevance to clinical diseases and diagnosis.