Note: Although highly pathogenic avian influenza (HPAI) H5 infections have been detected in U.S. domestic poultry, no human infections with these viruses has been detected.
Avian influenza, commonly called “bird flu”, is an infection caused by type A influenza viruses that normally only infect birds. The pathogenicity or ability of avian influenza viruses to cause disease in domestic poultry (chickens, ducks, and turkeys) tends to vary with the makeup or subtype of the virus. Subtypes that are classified as “low pathogenic” cause no noticeable disease or only very mild symptoms of illness in birds, such as ruffled feathers and a drop in egg production. Low pathogenic bird flu viruses are widely distributed in wild birds all over the world and do not pose a significant animal or public health threat.
Highly pathogenic avian influenza (HPAI) H5 infections have been reported in United States domestic poultry (backyard and commercial flocks), captive wild birds, and wild birds. H5 bird flu virus detections were reported in 21 states between December 2014 and June 2015. To date, no infected flocks have been identified in Oklahoma.
At this time, no human infections with these viruses have been detected in the U.S. Similar viruses have infected people in other countries and caused serious illness. Human infections with other avian influenza viruses have occurred after close and prolonged contact with infected birds or the excretions/secretions of infected birds (e.g., droppings, oral fluids).
The Centers for Disease Control and Prevention (CDC), U.S. Department of Agriculture (USDA), and the U.S. Department of Interior (DOI), are following the situation closely, and surveillance for H5 in U.S. birds is ongoing. It is possible that H5 outbreaks in birds in the U.S. may recur in the fall and winter. More information will be posted as it becomes available.