Prevalence of Food-Borne Toxoplasma gondii in Free-Ranging Chickens Sold in Tunis, Tunisia

Background: Toxoplasma gondii, as an important food-borne protozoan parasite, occurs widely in humans and animals including domestic poultry throughout the world. The goal of this survey was to determine prevalence rate of T. gondii in free-ranging chickens sold in Tunis, Tunisia. Methods: In the present study, the prevalence of T. gondii in 40 free-range chickens (Gallus domesticus) marketed in Tunis, Tunisia was assessed. Blood and brain samples from each chicken were examined for T. gondii infection using the Modified Agglutination Test (MAT) followed by mouse bioassay and Polymerase Chain Reaction (PCR). Results: Antibodies against T. gondii were found in all 40 samples (100%) with the titer of 10 in 14 chickens, 20 in 9 chickens, 40 in 3 chickens, 80 in 5 chickens, 160 in 6 chickens, 320 in 2 chickens and ≥640 in one chicken. By the end of the bioassay, we detected Toxoplasma DNA in 15 mouse tissues (37.5%). T. gondii was detected from chicken tissues with different antibody titers. Conclusion: Results of this study indicated very high environmental contamination with T. gondii oocysts around Tunis city. The high seroprevalence refers to the public health importance of chickens as source of zoonotic toxoplasmosis to human which suggests that consumption of poultry meat in Tunis city may pose a potential threat to pregnant women health and should be given attention.