Keeping Flu out of Chickens

Athens– The Georgia Poultry Federation has said that poultry farming accounts for 52 percent of the agriculture in Georgia, and 105 counties produce more than $1 million worth of chickens and turkeys every year.  This production contributes $15.1 billion Georgia’s economy every year and makes Georgia the leading chicken producing state in the U.S.  Keeping these birds healthy is big business not just for the farmers, but also for reseachers at the University of Georgia.

Keeping poultry healthy prevents bird diseases from mutating into more dangerous human diseases.  Chickens and humans have nearly incompatible immune systems, so, contrary to popular misconceptions, there is only a slight threat of diseases passing from birds directly to humans.  The flu must mutate an intermediary host to become infectious.

Veterinary virologist Ralph Tripp, a professor in the University of Georgia College of Veterinary medicine, has said that pigs are the likeliest transmission vectors because their immune systems are vulnerable to both bird and human diseases, giving bird viruses the perfect environment to mutate and become human diseases.  For Dr. Tripp, an avian flu epidemic is an impending danger, a matter of when and not if.

Professor Mike Lacy, head of poultry science at UGA, works directly with Georgia farmers in keeping their birds healthy and trains UGA students to find the most effective and economical ways to keep birds disease-free.  He advocates a holistic approach, where veterinarians and farmers protect the health of an entire flock instead of single birds.  To protect birds, farmers use genetic manipulation, nutrition, environmental control, and vaccinations.  Given the close quarters that chickens live in, diseases spread quickly, and in the case of certain diseases like avian flu, a single infected bird can cause the destruction of entire flock.

Dr. Tripp and other researchers at UGA have recently developed more effective vaccines by changing the genes within diseases.  For example, by adding an avian flu gene to a dead or weakened fowl pox germ, researchers can create a vaccine that protects against both diseases.     Vaccinations are expensive, and as the economy slows down, money for research has also dried up, said Dr. John R. Glisson, head of UGA’s Poultry Diagnostic and Research Center.  Glisson said newer vaccines that protect against more exotic and dangerous diseases are ten to twenty times more expensive than traditional vaccines.  Tripp concurred and said, “Many farmers and poultry companies find that it is much more economical to destroy birds than it is to vaccinate.”

Given the dwindling effectiveness and use of vaccines, how else can farmers protect chickens’ health?  One solution seems to be providing better biosecurity.  Biosecurity entails using series of routine procedures that systematically reduce the potential for infection.  Examples of bio-security include always sterilizing clothes, shoes, and tools before working with chickens, not interacting with multiple flocks, and keeping wild birds away from a flock.

“In most cases,” Lacy said, “a disease problem is traced back to a human being or equipment that has visited that flock.”  He explained that north Georgia farms suffer from the lowest bio-security standards in the Southeast, with outbreaks being caused by poor sanitation of workers and equipment.

Lacy said, “In an ideal situation, observers are vigilant, and diseased birds are dealt with quickly.”

Glisson points to a recent outbreak of mycoplasma gallisepticum, or MG as it is known in the industry, among farmers in North Georgia as an example of biosecurity’s importance.  When a single brick falls out of place, the entire building begins to fall.

After 40 years, said Glisson, the disease had been nearly wiped out, and farmers grew lax about vaccinating for it.  Younger farmers had never seen the disease, so they didn’t know what protect against.  Then, almost two years ago, the disease started to spread within one large operation that could not afford to kill all of its infected birds, said Glisson.

As poultry workers moved from farm to feed lot and back to farm, they became carriers of MG, and passed the disease among flocks at other farms.  The disease spread with unpredictable speed, proving just how quickly an epidemic can start when birds’ health goes unmonitored.  Glisson said chickens live in heavily controlled environments, so with due diligence, diseases can be very easily prevented.  By using the same methods that have been employed for nearly five decades, farmers can continue to keep dangerous disease like avian flu from mutating and spreading to humans.