Which of the following is NOT a reported way avian influenza is spread?

• A. Genetic mutation only
• B. Nasal discharge or droppings of an infected bird
• C. Windborne spores
• D. Water contamination in facilities

Answer: (A)

The main idea here is how avian influenza moves from one bird or environment to another. Genetic mutation only is not a way the virus travels between hosts; mutations change the virus's characteristics, not its physical transfer. Transmission happens when the virus is shed by an infected bird in nasal secretions or droppings and comes into contact with another bird, or via contaminated water or surfaces in facilities. Water contamination in facilities is a classic route because the virus can persist in water and be ingested by other birds. Windborne transmission can occur in aerosol form under some circumstances, though it’s not described in terms of spores (viruses aren’t spores), and it’s less relied upon as a primary route. So the idea of spreading by mutation alone isn’t a reported transmission route, making it the correct choice.