A wave of highly pathogenic avian influenza (HPAI, or “bird flu”) that began on Feb. 9 with an infected commercial flock of turkeys in Indiana has resulted in the depopulation of millions of birds and helped drive up the price for chicken, eggs and other products. In Illinois, HPAI was discovered in a flock of wild Canadian geese in March.
A nearly two-month restriction on backyard bird feeding was lifted by the Illinois Department of Agriculture (IDOA) on June 1, signaling a lessening of the severity of the threat. However, emergency rules remain in effect that prohibit the sale or exhibition of poultry and poultry products at many live events, including county and state fairs. IDOA on Tuesday announced both junior and open live shows at the Illinois State Fair will be cancelled.
But with the spring waterfowl migration complete and warmer, third weather in place, state veterinarian Dr. Mark Ernst is optimistic that the risk for transmission of HPAI will be significantly lower.
“HPAI has affected over 40 million birds in 36 states,” said Ernst, a Washington, Ill., native and graduate of the University of Illinois School of Veterinary Medicine. “(The severity) has started to drop some. We’re getting into the warmer summer months, so we’re getting fewer detections. Although in Colorado and some of the western states they are still picking up some infections, in our area the number of sick bird calls we are receiving has dropped off significantly.”
According to the United States Department of Agriculture (USDA) outbreaks of HPAI in the United States occurred in 2004 and again in 2014–15. More birds were lost either to death from the illness or depopulation in the 2014–15 outbreak than in any other infectious animal disease event in US history. The outbreaks affected poultry commerce on a global scale, decimating international demand for US poultry products while shattering profits for affected US producers in addition to producers whose flocks did not contract HPAI. Government efforts to mitigate the disease were effective but came at a great cost to taxpayers.
Ernst said the highly pathogenic form of avian influenza can affect a flock very quickly, with some producers reporting animals exhibiting no symptoms of HPAI in the morning and sudden death by the evening.
“Other signs that we can see in these birds can include a drop in egg production, a drop in feed and water consumption, and respiratory signs. Birds can be very lethargic. More common than not, we’ll see this acute phase where birds appear to be normal shortly before death, and will just drop over and die,” said Ernst.
The most common method of transmission of HPAI among the avian population is through direct contact with infected animals, or their droppings. Migrating wild waterfowl are the primary vessels for the spread of the disease, which can easily be transferred to unprotected backyard flocks and, as has been proven this year, into large, confined feeding operations.
Though more time will be needed to assess the financial impacts of the 2022 HPAI outbreak on US exports and producer profits, broiler producers’ losses in 2015 were estimated at between $332 million and $472 million. Not only were substantial price effects observed from lost access to international markets, but their effects also were compounded by the direct losses from lost birds, biosecurity costs, and disease control efforts, according to the USDA, whose Animal and Plant Health Inspection Service (APHIS ) estimated these losses at $879 million for the 2014–15 outbreak.
The transmission of HPAI to humans from avians is extremely unlikely but cannot be entirely ruled out, according to the IDOA’s top vet.
“HPAI is an influenza virus, and influenza viruses can and do mutate. However, in this particular instance there have not been cases where we’ve seen it spread to humans outside of a couple of cases where they have identified the virus but were unable to determine whether it was a true infection of a person, or whether the virus was present in the person’s airways without becoming infected,” Ernst said.
Though Illinois has lifted its ban on backyard bird feeders, the Illinois Department of Natural Resources (IDNR) is asking bird lovers to continue to avoid feeding ducks, geese and other congregating waterfowl. Because HPAI may remain in resident waterfowl, feeding waterfowl can lead to nuisance problems and increase the rate of disease transmissions, according to IDNR wildlife disease program manager Chris Jacques.
“IDNR would like to thank the public for their assistance and cooperation in potentially reducing the spread of HPAI during this critical time,” Jacques said in a May 31 IDNR news release.