Seroepidemiological study of Toxoplasma gondii in equines in Northern Egypt

Ehab Kotb Elmahallawy^1*Marwa Fouad Hassan²David Cano-Terriza³Nada Albalawi⁴Tomás Fajardo³Asmaa Aboelabbas Gouda⁵Ayman Atiba⁶Ahmed Hendawy⁶Isabelle Villena⁷Ashraf Mohamed Barakat⁸Hind Alzaylaee⁹Sonia Almeria¹⁰Ignacio García Bocanegra^3*

• ¹Department of Animal Health, Faculty of Veterinary Medicine, University of Cordoba, Cordoba, Spain
• ²Department of Biochemistry, Toxicology and Feed Deficiency, Zagazig branch, Animal Health Research Institute (AHRI), Agriculture Research Center (ARC), Dokki, Giza, Egypt
• ³Departamento de Sanidad Animal, Grupo de Investigación en Sanidad Animal y Zoonosis (GISAZ), Facultad de Veterinaria, Universidad de Córdoba, Córdoba, Spain
• ⁴Department of Biology, College of Science, Taibah University, Medina, Saudi Arabia
• ⁵Department of Parasitology, Faculty of Veterinary Medicine, Zagazig University, Zagazig, Al Sharqia, Egypt
• ⁶Faculty of Veterinary Medicine, Kafrelsheikh University, Kafrelsheikh, Kafr el-Sheikh, Egypt
• ⁷University of Reims Champagne-Ardenne, UR 7510, National Reference Centre for Toxoplasmosis, Laboratory of Parasitology, Reims Hospital, 51095 Reims, France
• ⁸Department of Zoonotic Diseases, National Research Centre, El Buhouth st., Dokki,, Giza, 12622, Egypt
• ⁹Department of Biology, College of Science, Princess Nourah bint Abdulrahman University, P.O. Box 84428, Riyadh, 11671, Saudi Arabia
• ¹⁰Division of Food and Environmental Safety, Office of Applied Microbiology and Technology (OAMT), Office of Laboratory Operations and Applied Sciences (OLOAS), Food and Drug Administration, Department of Health and Human Services, Laurel, Maryland 20708, United States

Introduction: Toxoplasmosis, caused by the intracellular protozoan Toxoplasma gondii (T. gondii), continues to be a widespread parasitic zoonotic disease globally. The seroepidemiology of T. gondii infection in Egyptian equids, particularly donkeys, remains insufficiently explored. The present study was designed to assess the seroprevalence of T. gondii in equines from Northern Egypt. Methods: A total of 360 serum samples from two equine species (157 horses and 203 donkeys) were obtained during 2023. The Modified Agglutination Test (MAT, cut-off of 1:25) was used to screen for the anti-T. gondii antibodies. The study also analyzed potential risk factors that could contribute to the exposure of the animals to the parasite, including species, breed, sex, age, and the specific location of each animal.Results: The overall seroprevalence of T. gondii among examined equines was 41.11% (95% Confidence Interval [CI]: 36.03-46.19). The relationships between seropositivity and explanatory variables were analyzed using a Generalized Estimating Equation (GEE) approach. The seroprevalence of T. gondii was significantly higher in donkeys (51.23%) than in horses (28.03%; p < 0.001; odds ratio [OR] = 2.99; 95% CI: 2.35-3.81).. Conclusions: Collectively, our findings revealed a high T. gondii exposure among equine species in Northern Egypt, with a notably higher seroprevalence in donkeys compared to horses. This study represents one of the most extensive serosurveys of T. gondii in equids conducted in Egypt, featuring the largest sample size of donkeys examined to date. It also examined previously unexplored risk factors related to parasite exposure in equids. The present findings highlight the critical importance of performing periodical surveillance, monitoring, and management of the parasite among equids, which might have a major impact on animal and public health.