Which symptom in humans is most often reported with Newcastle disease virus infection?

• A. None
• B. Conjunctivitis
• C. Mild respiratory signs
• D. Potentially life-threatening illness

Answer: (B)

In human infections with Newcastle disease virus, ocular exposure leading to conjunctival inflammation is the most commonly reported manifestation. The virus is an avian paramyxovirus and human disease is rare and usually mild, with the eye being a common entry point for infection after contact with infected birds or their secretions. This often presents as conjunctivitis with redness, tearing, irritation, and photophobia, and may be accompanied by mild systemic symptoms but not the severe, life-threatening illness seen with some other pathogens. While mild respiratory symptoms can occur, they are less consistently reported than conjunctivitis, making conjunctivitis the best answer.