Which of the following routes is explicitly identified as a route of transmission for HPAI and vND?

• A. Feces and respiratory secretions
• B. Biological vectors
• C. Contaminated fomites
• D. Both A and C

Answer: (A)

The key idea is that HPAI and vND are shed in both respiratory secretions and feces, making those materials common sources for transmission. Birds contaminate their surroundings with coughing, sneezing, nasal discharge, and droppings, so susceptible birds can become infected by inhaling aerosols or by ingesting material contaminated with those secretions or feces. These two routes are specifically and repeatedly identified in official guidance as ways the viruses spread between birds.

Biological vectors aren’t considered a standard or primary route for these avian viruses, so vector transmission isn’t listed as a typical pathway. While contaminated surfaces or equipment (fomites) can contribute to spread, the question points to routes that are explicitly identified in common references, and feces and respiratory secretions fit that criterion best. Therefore, feces and respiratory secretions are the explicit transmission routes, making the option that includes them the best choice.