Which equine respiratory disease would be the greatest threat to human handlers?

• A. Hendra
• B. Equine herpesvirus 4 (EHV-4)
• C. Equine adenovirus
• D. African horse sickness

Answer: (A)

Zoonotic potential and exposure risk shape how dangerous a horse disease is to people who handle them. Hendra virus can cross from infected horses to humans and cause severe, often fatal illness, making it a major occupational hazard for handlers who work with horses. In contrast, equine herpesvirus type 4 and equine adenovirus mainly affect horses and have little to no documented transmission to humans, so they pose far less direct danger to people. African horse sickness is primarily a horse disease transmitted by midges and is not considered a human zoonosis. Therefore, the greatest threat to human handlers among these is Hendra virus.