Record Avian Flu Outbreak Hit Turkey And Chicken Layer Flocks
The US has been hit with an avian influenza outbreak that, as of Thursday, May 7, 2015, involved 142 flocks and nearly 30 million birds. This is the largest outbreak the US has experienced and there are no signs that the death rate will stop at 30 million birds. The previous largest outbreak occurred in 1983 and continued into 1984, involving 17 million birds.
The outbreak began December 19, 2014 in a backyard mixed poultry flock in Douglas, Oregon. This event and two others in California involved a Eurasian strain for the flu designated H5N8. The remainder of the detections of avian influenza is of the H5N2 strain, the same strain responsible for the 1983 outbreak, although the two strains are not identical.
In the next column we will go into greater detail about the outbreak and the precautions that are being taken to contain it. Today, we want to discuss the impact or non-impact on the human population.
The USDA cautions people that “these virus strains can travel in wild birds without them appearing sick. People should avoid contact with sick/dead poultry or wildlife. If contact occurs, wash your hands with soap and water and change clothes before having any contact with healthy domestic poultry and birds.”
The current strains of avian influenza show no signs of bird to human transmission of the disease. In previous outbreaks, a few individuals with close and prolonged exposure to poultry litter and dust from poultry litter became infected. The Centers for Disease Control (CDC) “recommends that people who have had contact with infected bird(s) monitor their own health for possible symptoms. People who have had contact with infected birds may also be given influenza antiviral drugs preventatively.” More information can be found on the CDC website “Update: Outbreaks of Avian Influenza A H5 in U.S. Wild and Domestic Birds: Human Health Implications” (http://tinyurl.com/ljyw2du).
In the same update the CDC writes, “Most human infections with avian influenza viruses…have occurred in people with direct or close contact with infected birds. Limited transmission from person-to-person has been documented rarely, after very close and prolonged contact with someone who is sick. Sustained human-to-human transmission with avian influenza has not been documented.
“CDC considers the risk to people from these…H5 infections in U.S. birds and poultry to be low at this time because infections with avian influenza viruses are rare and – when they occur – these viruses have not spread easily to other people. However it’s possible that human infections with [the] viruses associated with these outbreaks in birds may occur at some time.”
While the current outbreak primarily involves laying hens and turkeys, “there is no evidence that any human cases of avian influenza have ever been acquired by eating properly cooked poultry products.”
At present, the biggest impact this outbreak is having on the human population is economic. For the farmers of the affected flocks, they are compensated by the USDA for the birds that are humanely slaughtered to prevent the spread of the disease. They are not compensated for the birds that die of the avian influenza before the culling begins. They are also not compensated for the cleanup process that can take two to three months to complete.
Because the greatest number of outbreak events have occurred on turkey farms and now is the time that these growers are raising the birds that will be in the grocery freezer case come Thanksgiving and Christmas, the number of turkeys available may be impacted. But this impact will be mitigated by the US stockpile of frozen turkeys.
Though the impact of the disease on chickens has been concentrated on laying hens, the export of poultry products to a number of destinations has been halted. The result of this and the strong dollar will be seen in the greater availability of dark meat – the type of meat that makes up the bulk of US chicken exports – in the coming months. According to Bloomberg News Tyson Foods has announced that it “is working to use more dark meat in processed chicken dishes for both retail and food-service customers. ∆
DR. HARWOOD D. SCHAFFER: Research Assistant Professor at APAC, University of Tennessee
DR. DARYLLE E. RAY: Blasingame Chair of Excellence in Agricultural Policy, Institute of Agriculture, University of Tennessee