Seroprevalence of Toxoplasma gondii and Neospora caninum and Evidence of Microsporidia Infections in Rural Red Foxes

Thoracic fluid from 206 and 220 foxes were examined for antibodies to Toxoplasma gondii and Neospora caninum using indirect immunofluorescent antibody tests (IFAT). A total 115 (56%) and six (3%) foxes had antibodies to T. gondii and N. caninum respectively. The brains from 148 foxes were examined for histological lesions and pathological changes suggestive of parasitic encephalitis were observed in 33 (22.3%). Two thirds of these foxes had antibodies to T. gondii and one fox had antibodies to both T. gondii and N. caninum. PCR assays for T. gondii and N. caninum, on DNA extracted from the brains with histological lesions, were negative. However, microsporidian DNA was amplified from the brains of two of these foxes. Sequencing these amplicons revealed 100% homology with Encephalitozoon (Septata) intestinalis in one fox and Encephalitozoon cuniculi in the second fox. This is the first report of Encephalitozoon infections in wildlife in Ireland.