Seroprevalence of Toxoplasma gondii in Equids: A Global Systematic Review and Meta-analysis

Toxoplasmosis is a zoonotic infectious disease caused by T. gondii, a widely distributed obligate intracellular parasite. It has received widespread attention because it can infect a large number of domestic and wild animals, thereby posing a threat to public health and the economy on a global scale. Among them, equine animals are critical intermediate hosts. However, studies on T. gondii infection in equine animals are currently not systematic on a global scale. For this purpose, we conducted a systematic review and meta-analysis.

This study searched for relevant studies in six significant databases (PubMed, Web of Science, ScienceDirect, Wanfang database, VIP database and CNKI database). From 1099 articles, we selected 30 articles from 17 countries published from the database creation to July 1, 2023, and used a random-effects model to estimate the T. gondii infection rate in equids.

The global infection rate of T. gondii in equids was estimated at 15.0% (2539/15,882, 95% CI 14.0-15.0%). The infection rate was highest in Africa (25.5%) and lowest in North America (8.4%). The infection rate after 2016 (24.0%) was higher than that before 2016 (14.6%). The infection rate was highest in equids aged 5-10 years (20.3%). Among equids, donkeys had the highest overall infection rate at 23.4%, which was higher than that of horses (15.8%) and mules (16.8%). The infection rate among female equine animals (17.5%) is higher than that among males (13.9%). These data indicate that T. gondii is widespread among equine animals globally, posing a potential infection risk to humans. Therefore, continuous monitoring of toxoplasmosis infection rates and control of T. gondii transmission are of great significance for both economic and public health.