Estimation of Toxoplasma gondii seroprevalence in sheep in Sidi Bel Abbes, Algeria

Sheep are considered as an important reservoir of human Toxoplasma gondii infections, although more recent data on the prevalence of T. gondii in sheep in Algeria are lacking. This study aimed to investigate the seroprevalence of T. gondii in sheep to obtain a better insight into the importance of sheep as reservoirs of human infection. A commercial ELISA kit, which detects antibodies against T. gondii, was utilized to test 269 sera collected from yearling sheep in the municipal slaughterhouse of Sidi-Bel-Abbes city between October 2020 and February 2021. Simultaneously, we assessed the cut-off as recommended by the manufacturer (S/P>50%) and the bootstrap statistical model to estimate the optimal cut-off value (OD = 0.12). The overall seroprevalence was estimated at 34.2% (92/269) using the ELISA kit cut-off and 50.5% (136/269) using the bootstrapped cut-off, being significantly higher compared to sheep from other regions in Algeria. In conclusion, the seroprevalence of T. gondii in sheep was elevated, constituting, therefore, a major public health concern, as sheep meat could be a significant source of T. gondii infection for human consumers. Further studies are required to estimate the impact of abortion among livestock animals caused by T. gondii infection such as sheep, where it could lead to considerable economic losses.