Seroprevalence and Risk Factors for Toxoplasma gondii Infection in Horses

SIMPLE SUMMARY: Toxoplasma gondii is classified as intracellular protozoa and is one of the major zoonotic parasites. Mares, horses of mixed breeds, and older than five years are substantially more likely to contract T. gondii infection. In addition, horses raised in contact with cats or domestic ruminants are more likely to test positive for T. gondii infection. This study confirms that horses in Northern Egypt are exposed to T. gondii and raises the possibility that people and other animals could contract the disease. ABSTRACT: Background: Toxoplasma gondii is classified as intracellular protozoa and is one of the major zoonotic parasites. Most warm-blooded intermediate hosts, including humans, are commonly infected by this parasite. The epidemiology of T. gondii infection in Egyptian horses is currently poorly understood. Methods: 420 blood samples were randomly collected from horses raised in four governorates in Northern Egypt (110 each from Giza and Kafr El Sheikh, and 100 each from Qalyubia and Gharbia) to investigate the existence of antibodies against T. gondii using a commercial ELISA kit, and to ascertain the risk factors for the infection. Results: the antibodies for T. gondii were found in 16.2% (68/420) of the examined horses, with no significant differences among the four studied governorates. The highest prevalence rate was observed in Giza. The results revealed that sex, breed, age, and contact with domestic ruminants or cats were recognized as potential risk factors. The high prevalence rate was found in mixed breed horses (OR = 2.63, 95% CI: 0.95–7.26), mares (OR = 2.35, 95% CI: 1.31–4.19), and horses aged over 10 years (OR = 2.78, 95% CI: 1.30–3.44). Moreover, the likelihood of seropositivity for T. gondii infection was higher in horses raised in environments with cats (OR = 1.97, 95% CI: 1.13–3.44, p = 0.017) or domestic ruminants (OR = 2.16, 1.21–3.86, p = 0.010). This report confirms that horses in Northern Egypt are exposed to T. gondii and thus raises the possibility that people and other animals could contract the disease. Conclusions: routine examination and management of T. gondii infection in horses in these governorates is advised.