Bovine Besnoitiosis : First Outbreak in Beef Cattle in Sardinia Island

Besnoitia besnoiti, the causative agent of Bovine Besnoitiosis (BB), was firstly signaled in Italy in 1994 in cattle imported from France, while autochthonous cases were registered in North-Central Italy since 2009. Recently, a serosurvey detected cases of infection in dairy and beef cattle bred in North-eastern Italy, while any case was not found in Sardinia. Here, an outbreak of BB in a sardinian beef cattle herd (Lula, Nuoro) is described. A Limousine bull 4.5 year-old, imported from France, showed since one year cutaneous lesions imputable to BB and pathognomonic cysts in the scleral conjunctiva. Any other animal in farm did not show clinical sign of BB. A serological screening was carried out to detect antibodies anti-B. besnoiti in all the herd using two sequential tests in order to increase sensitivity and specificity: a commercial ELISA (Id Screen® Besnoitia Indirect 2.0) followed by a confirmatory tachyzoite-based Western Blot (WB) performed under non-reducing conditions. Seropositivity was detected in 22 out of 39 examined animals (56.4%) by ELISA but 17 were confirmed by WB (P=43.5%). Two positive individuals were males, including the bull with clinical signs. All other positive cattle were Limousine imported or born in farm besides a two year-old Sardo-Bruna cow, born and breed in Sardinia. Our results confirmed the spread of the infection within the herd, probably as a consequence of the introduction of the infected bull from France. Animal trade among countries is thus confirmed as an important risk factor associated to BB. Sanitary authorities are therefore urged to update legislation (i.e. serological control of animals imported from endemic countries) and to set up adequate intervention on sanitary training