That Horse Bit Me: Zoonotic Infections of Equines to Consider after Exposure Through the Bite or the Oral/Nasal Secretions

Millions of individuals are in contact with horses through occupational or recreational activities. Injuries from horses are responsible for over 100,000 emergency room visits each year in the United States. Although various types of traumatic injuries related to direct contact with horses are well described, roughly 3% to 4.5% of all reported injuries are due to bites by equines. The immediate injuries are commonly either blunt or penetrating trauma to local tissue; however, the bite exposure may also transmit a microbial agent of equine origin that can lead to a zoonotic infection. In almost all jurisdictions in the United States, animal bites are considered public health events and should be reported to the local health departments. Many animals can harbor many unusual zoonotic pathogens that both the individual health provider and public health officials much consider as they can adversely impact both the patient and the community health. This review focuses on those zoonoses that have been reported in the literature, including those that may in theory be transmitted from equine to human by direct inoculation or exposure to oral/nasal secretions from horses and other equine species.