Wild birds, particularly migratory waterfowl, can contract and transmit both low and highly pathogenic avian influenza viruses. The Animal and Plant Health Inspection Service with the U.S. Department of Agriculture encourages hunters and other persons engaging in outdoor recreation to help track the avian flu.
A standard protocol of biosecurity practices is recommended for poultry growing operations, from small backyard flocks to those that raise tens or hundreds of thousands of birds. These precautions are intended to prevent and limit the spread of the avian influenza virus.
Avian influenzas, including the highly pathogenic varieties, can infect birds both wild and domesticated. Birds carrying the virus can pass it on to other birds through airborne contact, as it is found in respiratory secretions and saliva.
The 2015 avian influenza epidemic was the largest in U.S. history, affecting more than 48 million domestic poultry birds in 15 states between December 2014 and June 2015, according to the U.S. Department of Agriculture's Animal and Plant Health Inspection Service.