FDA continues to deliberate actions to control antimicrobial resistance

Washington-The Food and Drug Adminis-tration (FDA) is still gathering input about its proposal to curb antibiotic drug resistance.

FDA's Center for Veterinary Medicine asked both the American VeterinaryMedical Association (AVMA) and the Animal Health Institute (AHI) to delivertheir arguments on a proposed risk-management system to evaluate new andexisting animal antibiotics. Both associations have voiced concerns overthe proposal.

Dr. Michael Apley, of Iowa State University and vice chair of AVMA'ssteering committee on antimicrobial resistance, delivered the AVMA statementto FDA's Anti-Infective Drugs Advisory Committee meeting Jan. 8-9. Dr. RichardCarnevale spoke on behalf of AHI, an industry organization that representsanimal health manufacturers.

The January meeting came in the wake of two key events in late 2002.

* Consumer Reports published results of a study citing extensivecontamination of samples from store-bought chicken with campylobacter andSalmonella, including resistant strains. Outcome: Industry reaction is thatit's no knockout for limiting antibiotic use in poultry, but it may erodeconsumer confidence about the safety of the food supply.

* Industry groups submitted comments to FDA about its plan toevaluate the safety of antimicrobial new animal drugs with regard to theirmicrobiological effects on bacteria of human health concern. Outcome: AVMAis very concerned that the result will be a worsening veterinary drug shortage,and possible restrictions on extra-label use of antibiotics for veterinarians.

The latest FDA meeting was to gather more scientific opinion on the subjectin order to postulate its final guidance document, which will spell outhow antibiotics are approved in the future. Veterinary officials won't evenhazard a guess on when the final guidelines will be released. FDA's draftguidance was in the works for about three and a half years.

Thumbs down on poultry

It all comes on the heels of a Consumer Reports study that is down onpoultry production. But it's not all about chickens. The issues are aboutprotecting animal health, preserving veterinarians' clinical judgment withextra-label use and maintaining an arsenal of FDA-approved veterinary antibioticswhile not unleashing resistant strains of bacteria that could make peoplesick.

Ron Phillips, AHI's vice president of legislative affairs, says of theConsumer Reports study, "There is a grand war being fought here, andthe issue is food safety."

The Center for Science in the Public Interest (CSPI), a consumer advocacygroup that is calling on FDA to ban certain antibiotics from productionanimal medicine, was quick to issue a statement following publication ofthe Consumer Reports study. CSPI states, "Consumer Reports' findingsmeant that food poisoning illnesses from chicken are likely to be more serious,causing more doctor visits, longer hospitalizations, and more deaths becauseof antibiotic resistance. It's good news that there is less bacteria onchicken generally, but it is very bad news that more of that bacteria isresistant to the kinds of antibiotics used to treat serious food poisoning."

Results showed that 42 percent of samples harbored campylobacter, downfrom 63 percent in 1997. For Salmonella, 12 percent tested positive, downfrom 16 percent in 1997.

The testing

But while the Consumer Reports study showed an increase in resistantforms of bacteria, the data on poultry isn't as bleak as it looks, saysVogel.

In fact, the highest percentage of resistance was found in campylobacterto tetracycline, and this antibiotic is not used to treat campylobacteror Salmonella infections. The most common choice for physicians is ciprofloxacinand the report showed no resistance in Salmonella. The report did show resistanceto campylobacter by 26 percent of samples, which was higher than data fromthe government's National Antimicrobial Resistance Monitoring System (NARMS).

Vogel adds, "This is kind of questionable, and it makes you wonderabout the sampling and testing methodologies done by Consumer Reports andhow comparable that really is to other larger sampling programs like NARMS."

Phillips adds, "This little media event that was generated by ConsumerReports and their activist friends is not going to have an impact. It ismore of an effort to lead the public down a road that doesn't have basisin fact."

Recommendations made by Consumer Reports were to require companies tomonitor data on the use of antibiotics in food animals and ban the subtherapeuticuses of "medically important drugs in poultry and other livestock."

Vogel says, "I wish they would have explained more clearly whichantibiotics are used to treat Salmonella and campylobacter infections inhumans rather than just testing for a number of them and inferring thatthere is a bigger problem than there really is."

Even though the study received national media attention after its publication,veterinary officials don't believe that it will impact the new rules FDAis currently mulling over.

Making comments

Last December, industry groups submitted comments to the agency for reviewon its proposed plan to prolong the effectiveness of antibiotics.

AVMA's position pointed out the following areas of concern:

* This proposed risk analysis did not include an important component- risk communication. In other words, what is the level of risk the publicis willing to accept?

* Simply limiting veterinary antibiotic use may jeopardize animalhealth and welfare without providing a benefit to human health.

* FDA needs to re-evaluate how it measures the importance of antibioticsto human medicine.

* Limiting extra-label use of drugs was cited as a risk managementtool. AVMA cautions against an overly conservative approach that would putadditional drug use restrictions on veterinarians.

* The potential withdrawal of approved antibiotics would onlyfurther the veterinary drug shortage.

Vogel says that AVMA is very concerned that FDA will push to decreaseuse of antibiotics without a risk-benefit analysis. Vogel adds this approachalone just won't work. And that sentiment has been espoused by FDA's DeputyCommissioner Dr. Lester M. Crawford, who says FDA's strategy is to controlor reduce antimicrobial resistance while still treating animals.

AVMA states, "Therefore, additional requirements for new animaldrug approvals, and retention of current approvals, must be applied prudentlyto balance the needs of public health, and animal health and welfare."

Vogel adds that the antibiotic resistance issue is not isolated to justfood animal medicine. Beginning last month, the FDA is making availablethe most recent AVMA documents on judicious use of antimicrobials for beefand dairy producers. All in all, AVMA has drafted seven different judicioususe principles for all the major species, including companion animals.