Migratory Wild Birds as Potential Long-Distance Transmitters of Toxoplasma gondii Infection.

Toxoplasma gondii is a worldwide distributed zoonotic protozoan capable of infecting a wide range of mammals (including humans) and birds as intermediate hosts. Migratory wild birds, through interconnecting countries along their flyways, can play a role in the spatial spread of T. gondii and could contribute to its sylvatic cycle. Additionally, hunted wild birds used for meat consumption could represent a further source of human infection. To determine the presence of T. gondii in wild birds, a total of 50 individuals belonging to the Anseriformes and Charadriiformes orders were sampled during the 2021-2022 hunting season in Northern Italy. Cardiac muscle samples of three Northern shovelers ( Anas clypeata) , two wild mallards ( A. platyrhynchos ), one Eurasian teal ( A. crecca ), and one Northern lapwing ( Vanellus vanellus ) were positive for the molecular detection of T. gondii based on a targeted amplification of the B1 gene. A 14% (7/50) overall positivity was observed in the sampled population. Results from this study suggest a moderate exposure of wild aquatic birds to T. gondii , highlighting the importance of a further characterization of T. gondii in its wildlife hosts.