SEROPREVALENCE FOR TOXOPLASMA GONDII INFECTION IN WILD BOAR AND FINISHING SWINE IN NORTHERN ITALY

Objectives - The EFSA has recently recommended that Toxoplasma monitoring programmes should be initiated in the preharvest sector on sheep, goats, pigs and game. The aim of the present study is to determine the seroprevalence of T. gondii in wild boar and in confined swine in Northern Italy, an area accounting for over 80% of the Italian swine production. Materials and Methods - The study involved a total of 400 fattening pigs, randomly sampled in a main abattoir and 427 wild boars collected during 2010-2011 hunting season. Samples of meat juice were examined for specific antibodies by a commercial ELISA test (IDvet T. gondii serum screening). Muscolar tissue of seropositive animals (diaphragm and hearth) were further examined for directly detecting the parasite contemporary by PCR and bioassay in mice. Results - Seroprevalence against Toxoplasma gondii was 17.3% (CI 95%: 13.9-21.3%) in wildboar and 5.25% (CI 95%: 3.28%- 7.91%) in slaughtered fattening pigs. Amongst the 95 seropositive samples, 3 muscolar tissues were positive by PCR, instead all bioassayed samples were negative. Conclusions - Data from different studies are not directly comparable due to the variability in the sampling strategy and in the type of method applied for the testing. However, our data demonstrate a high difference in seroprevalence (χ2=29.62; p<0.05) between the wildboar sampled population and the farmed pigs even in the same study area. This survey confirms the low infection rates in animals reared indoors and suggests that the maintenance and the implementation of biosecurity measures can prevent the exposition to contaminated environment. The level of this agreement between indirect and direct tests indicates that presence of antibodies is not a good indicator for the presence of viable T. gondii muscolar cystis.