True/False: Only virulent Newcastle disease has been seen in the U.S.; highly pathogenic avian influenza has not yet occurred.

• A. True
• B. False
• C. Not enough information
• D. Both have occurred in the U.S.

Answer: (B)

The concept being tested is that multiple highly pathogenic avian viruses have appeared in the United States, not just virulent Newcastle disease. In the U.S., virulent Newcastle disease (velogenic NDV) has certainly occurred, but highly pathogenic avian influenza (HPAI) has also caused widespread outbreaks in poultry and wild birds, including notable HPAI events in past years. Because HPAI outbreaks have been documented, the statement that only Newcastle disease has been seen and that HPAI has not occurred is false. In other words, both diseases have appeared in the U.S., which is why the best answer is that the statement is incorrect.