Could chickens infected with low pathogenicity avian influenza serve as the source of virus for a flock affected by highly pathogenic avian influenza?

• A. Yes
• B. No
• C. Only if co-infected with the high pathogenic strain
• D. It’s not possible for LPAI to spread to a different flock

Answer: (A)

Transmission dynamics between flocks allow a low pathogenic avian influenza (LPAI) infection in one flock to become the source of virus for another flock. LPAI can be shed and spread through direct contact, contaminated equipment, personnel, water, or shared environments. In poultry, certain LPAI strains, particularly H5 or H7, have the capacity to mutate in a susceptible flock and acquire a multibasic cleavage site in the hemagglutinin, transforming into highly pathogenic avian influenza (HPAI). So a flock harboring LPAI can indeed seed an HPAI outbreak in a neighboring or nearby flock, especially when biosecurity gaps exist.