A Systematic Review and Meta-Analysis on the Occurrence of Toxoplasmosis in Animals Slaughtered in Brazilian Abattoirs

SIMPLE SUMMARY: Toxoplasmosis is a zoonosis primarily transmitted via the consumption of infected/contaminated meat/vegetables/fruits, resulting in several years of disability-adjusted life. In Brazil, a high prevalence of toxoplasmosis has been recorded, and it affects hundreds of people. Several studies have been performed in Brazil to determine the occurrence of toxoplasmosis in animals at different levels of the food chain. However, to fully understand the situation in the country, there is a need to compile the studies performed in abattoirs establishing Toxoplasma gondii prevalence, its risk factors, as well as the infectivity of seropositive animals. Thus, we performed a systematic review gathering data on the prevalence and risk factors for toxoplasmosis in animals slaughtered in Brazil and performed a meta-analysis of its prevalence for different species and regions. Based on the results, we also discussed the infectivity of seropositive animals, risk factors, and the preventive strategies to avoid this zoonosis. ABSTRACT: Toxoplasmosis is mainly transmitted to human beings through the consumption of contaminated food, and several outbreaks caused by infected meat consumption have been reported in Brazil. We performed a systematic literature review on the prevalence and risk factors for toxoplasmosis in slaughtered animals and performed a meta-analysis of its prevalence for different species and regions. Furthermore, we also discussed the infectivity of seropositive animals, risk factors, and preventive strategies. In the meta-analysis, the overall prevalence estimates for poultry, ostrich, goats, swine, equids, sheep, and bovines were 42.4, 40.4, 23.0, 19.9, 19.1, 17.3, and 16.2%, respectively. Regarding the Brazilian regions, the highest prevalence values were detected for bovines and equids in the South (32.3 and 34.4%, respectively) and swine, goats, sheep, and poultry in the Northeast (29.3, 23.0, 22.9, and 69.8%%, respectively). High proportions of Toxoplasma gondii viability in bioassay conducted on seropositive animals were seen for sheep (34/40 = 85%) and swine (12/15 = 80%). Toxoplasma gondii infections are widespread on Brazilian farms, and the summarized data allow the establishment of high-priority areas and/or species for the adoption of preventive strategies to control this parasite at different levels of the food chain.