Big data gaps on animal drugs and antibiotic resistance

Robert Roos  News Editor

Sep 16, 2011 (CIDRAP News) – The US government needs to collect much more data on antibiotic use in food animals and resistant bacteria in animals and retail meat to clarify the possible links between them, the Government Accountability Office (GAO) said in a report released this week.

Government agencies have collected some data, but the data "lack crucial details necessary to examine trends and understand the relationship between use and resistance," the GAO said. The agency also said a shortage of data makes it unclear whether a voluntary strategy the government uses to deal with concerns about older antibiotics is working.

A number of medical, public health, and food safety groups for years have been advocating restrictions on the use of antibiotics in food animals, because of concern that excessive use gives rise to resistant bacteria, which can then spread to humans via food.

As noted in the report, however, the Food and Drug Administration (FDA) has banned just one antibiotic for use in food animals out of concern about encouraging bacterial resistance. In 2000 the FDA proposed to ban the use of two fluoroquinolones, enrofloxacin and sarafloxacin, in poultry. The maker of sarafloxacin voluntarily withdrew the product, but the enrofloxacin manufacturer opposed the move, and it took the FDA until 2005 to finally ban its use in poultry.

The new GAO report repeats the main thrust of a report issued in 2004, in which the agency called for improved data collection and risk assessment.

"Since GAO's 2004 report, FDA began collecting data from drug companies on antibiotics sold for use in food animals, but the data do not show what species antibiotics are used in or the purpose of their use, such as for treating disease or improving animals' growth rates," the new report says.

"Also, although USDA [US Department of Agriculture] agencies continue to collect use data through existing surveys of producers, data from these surveys provide only a snapshot of antibiotic use practices," it says.

Further, the agencies' data on resistance are not representative of food animals and meat across the nation and, because of a change in sampling method, in some cases have become less representative of the national picture since 2004, the GAO concluded.

The report says that a voluntary process that the FDA implemented in 2003 to assess risks associated with new antibiotics for animals is working reasonably well, but the process for limiting risks related to older antibiotics has problems.

In 2003 the FDA issued guidance to help drug sponsors evaluate potential risks to human health associated with new animal antibiotics. FDA documents say this guidance has been effective in limiting risks, according to the report. In addition, representatives of some producer, public health, and veterinary groups, along with an animal pharmaceutical organization, told the GAO they were "generally satisfied with the risk assessment approach," though they raised some concerns. More