A systematic review zoonotic diseases from horses

Worldwide, horses play a critical role in recreation, food production, transportation, and working animals. Horses roles differ by geographical region and the people's socioeconomic status. However, despite modern advances in transportation, which have in some ways altered humans contact with horses, potential risks for equine zoonotic pathogen transmission to humans occur globally. While previous reports have focused upon individuals or groups of equine pathogens, to our knowledge, a systematic review of equine zoonotic has never been performed. Using PRISMA systematic review guidelines, we searched the English literature and identified 233 previous reports of potential equine zoonoses found in horses. We studied and summarized their findings to identify risk factors that favor disease transmission from horses to humans. These previous reports identified 56 zoonotic pathogens that have been found in horses. Of the 233 articles, 13 involved direct transmission to humans (5.6%). The main potential transmission routes included oral, inhalation, and cutaneous exposures. Pathogens most often manifest in humans through systemic, gastrointestinal, and dermatological signs and symptoms. Furthermore, 16.1% were classified as emerging infectious diseases and thus may be less known to both the equine and human medical community. Sometimes, these infections were severe, leading to human and equine death. While case reports of zoonotic infections directly from horses remain low, there is a high potential for underreporting due to a lack of knowledge among health professionals. Awareness of these zoonotic pathogens, their disease presentation in horses and humans, and their associated risk factors for cross-species infection are essential to public health officials, clinicians, and people with recreational or occupational equid exposure.