Toxoplasma gondii in wild boar and roe deer in Northern Italy : serosurvey and PCR-RFLP

Toxoplasma gondii infects all warm-blooded animals; in Europe several studies carried out in wildlife show seropositivity towards this parasite, in particular in wild ungulates. In Northern Italy in the last years the culling of wild boar and roe deer is significantly increased and then the game meat consumption. As eating of raw or undercooked meat is a risk factor for Toxoplasmosis transmission to humans, we performed a serosurvey for this protozoan and its research in the muscular tissue. The samples were collected during the 2008 and2009 hunting seasons; wild boar sera were tested by IFIT (Toxo-spot ®IF, bio-Meriaux) while roe deer by a commercial Elisa kit (ID Screen® Toxoplasmosis Indirect ELISA, IDVET, Montpellier, France); we analysed respectively 281 and 505 sera:. 63 wild boar (22.4%, I.C. 95% 17.77-27.84) and 110 roe deer sera were positive (21.78%, I.C. 95% 18.31-25.69). We further examined the muscular tissues of the seropositive animals for directly detecting the parasite by a PCR-RFLP assay targeting the 18S small-subunit ribosomal gene of T. gondii. The PCR was carried out on samples of muscular tissue (heart, diaphragm and masseter) of 53 seropositive wild boar and from 49 hearts of seropositive roe deer. All the samples tested negative. By the restriction enzyme analysis of the amplified products we detected positive samples for Sarcocystis spp., that by sequencing analysis has been identified as S. miescheriana in wild boar and as S. cruzi and S. gracilis in roe deer. Although we couldn’t detect the parasite in muscular tissue, the serological results show a remarkable exposure to T. gondii in both host species and recommend a correct information and public health implication, also considering that consumption of undercooked or cured game is a widespread habit.