Serological survey of Toxoplasma gondii and Besnoitia besnoiti in a wildlife conservation area in southern Portugal

Toxoplasma gondii and Besnoitia besnoiti are closely related apicomplexan protozoa. T. gondii is a zoonotic pathogen which may cause serious disease in man and warm-blooded animals, including wild species. B. besnoiti causes bovine besnoitiosis, an emergent disease in Europe, which is linked to important production losses. Unlike T. gondii, the life cycle of B. besnoiti remains a mystery, since the definitive host has not yet been identified. The aim of this work was to determine the seroprevalence of T. gondii in wildlife and feral cats from a hitherto unsampled area in southern Portugal and to identify likely candidates for definitive and/or other intermediate hosts of B. besnoiti. A total of 260 animals were screened for T. gondii and B. besnoiti by the modified agglutination tests, using the cut-off value of 1:20 and 1:80, respectively. The prevalence of T. gondii was 85.3% in Egyptian mongoose (Herpestes ichneumon; n=34), 83.3% in wildcats (Felis silvestris; n=6), 66.7% in stone martens (Martes foina; n=6), 47.1% in genets (Genetta genetta; n=17), 40% in foxes (Vulpes vulpes; n=25), 39.2% in cats (Felis catus; n=79), 33.3% in European polecats (Mustela putorius; n=3), 21.4% in red deer (Cervus elaphus; n=14), 7.7% in wild boars (Sus scrofa; n=26), 2.8% in rabbits (Oryctolagus cuniculus; n=36) and 0% in European otters (Lutra lutra; n=2), European badgers (Meles meles; n=6) and rodents (n=5). None of the species tested was positive for B. besnoiti. Based on the present results, the monitoring of T. gondii in native animal populations may be of major importance for wildlife conservation strategies and human health protection, while the search for other hosts of B. besnoiti requires further investigations in wild and domestic species.