The US Food and Drug Administration (FDA) decided on Thursday to forbid the use of Bayer's antibiotic Baytril in the poultry industry, saying use of the drug has lead to increased occurrences of antibiotic-resistant food-borne infections in people.
FDA Commissioner Lester Crawford ordered the withdrawal of the approval for use of the drug in the poultry industry, and the ban will be effective as of Sept. 12.
Scientific data has shown that the use of the drug, generically known as enrofloxacin, caused resistance in a bacteria normally harbored in the digestive tracts of chickens and turkeys, called campylobacter bacteria, the FDA said.
Enrofloxacin, part of a family of drugs known as fluoroquinolones, does not completely eliminate campylobacter, and the surviving bacteria develop a resistance which then makes fluoroquinolones less effective in treating people.
Baytril has been licensed since 1996 to treat respiratory disease in chickens. Since then, strains of antibiotic-resistant campylobacter have increased, now accounting for 21% of the 1 million campylobacter infections in people each year, says Rob Tauxe of the Centers for Disease Control and Prevention.
In 2000, the FDA became "concerned that the drug was no longer safe," said Stephen Sundlof, director of the FDA's Center for Veterinary Medicine. It moved to withdraw approval for the use in chickens of Baytril, made by Bayer, and a similar drug made by Abbott.
Abbott complied, but Bayer appealed through a five-year legal process ending with FDA Commissioner Lester Crawford's decision to withdraw the drug's approval. Unless Bayer appeals further to an appellate court, or asks the commissioner to reconsider, the decision will go into effect Sept. 12.
The FDA ruling does not apply to the use of Baytril in other animals, which do not pass campylobacter to humans.
"We applaud the decision," Tauxe said. "People with campylobacter infections in the future will be easier to treat, and their infections will be shorter."
Campylobacter, which live in the digestive tracts of poultry, can cause cramps, fever and bloody diarrhea when they get into humans, and can lead to complications such as arthritis or life-threatening blood infections.
Baytril, when given to chickens, kills some of the bacteria, but those that survive become resistant to antibiotics such as Cipro, the standard treatment for campylobacter. These drug-resistant strains can pass into people who eat undercooked chicken.
On the other hand, there are experts, who think the U.S. administration decision is ill-considered.
It is a drug of last resort to fight respiratory diseases in poultry and is used on 1% or less of chickens and turkeys in the USA, Bob Walker of Bayer Animal Health in Shawnee Mission was quoted as saying by USA Today. "The poultry industry will only use it when they 100% need it," he said.
Respiratory illnesses can infect entire flocks, some as big as 20,000 birds, very quickly. "Mortality can reach 100%, and this was the only medication that was really effective in some of these infections," Loeb said. Chickens represent a $50 billion market in the USA.