Anti-biotics and hormones get vote of confidence of top scientists
"In 50 years of antibiotic use in animals and man, the development of resistance in animals has not made a major impact on human and animal health, and such a development seems unlikely to happen overnight now," said Dr Ian Phillips, Emeritus Professor of Medical Microbiology at the medical school of Guy's and St. Thomas' Hospitals at the University of London.
Dr Phillips chaired a group of experts who released their findings at the 42nd Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in the US.
Their results suggest that while there is a theoretical hazard to human health from the use of antibiotics in food animals, the actual risk is extremely small in stark contrast to the potential risks of animal medicines highlighted by a number of high profile cases in recent years.
The expert group evaluated data on the effects of antibiotics in humans and animals, and attempted to confirm or deny antibiotic resistance in animals transferring to humans. There is undoubtedly resistance, and some resistant organisms can reach man via the food chain, but little additional harm results from resistance, even when infection occurs, they concluded.
Much debate has centred on antibiotics to promote animal growth. These are permitted in the US but banned in the EU. Antibiotic-resistant bacteria which cause no disease in animals but can cause disease in man have given rise to worries. But new data shows that enterococci resistance is increasing in Europe, even though antibiotic growth promoters have been withdrawn.
According to Dr Ronald N Jones, of the SENTRY Antimicrobial Resistance Surveillance global network, increasing resistance is not due to resistant strains of animal origin, but to antibiotic use in humans. In Denmark, where antibiotic growth promoters were phased out between 1997 and 1999, pigs get more cases of diarrhoea and have slower post-weaning growth rates and increased production costs. They require more therapeutic antimicrobials, use of which jumped more than 90% since the withdrawal of growth-promoting antibiotics.
At the same time, human cases of salmonella and campylobacter have reached record levels in Denmark. The group of experts concluded that banning any antibiotic usage in animals, in the absence of a full risk assessment, is not useful and could even be harmful to both human and animal health.
"Rather than banning antibiotics in animals, we believe that efforts should focus on reducing the transmission of all foodborne pathogens, regardless of their antibiotic susceptibility," said Dr Phillips. "This can only occur through insistence on good hygienic practices on farms, in abattoirs, during distribution and marketing of food, and in the proper handling and cooking of food, and must be accompanied by consumer vigilance. Considerable progress has been made in the US as demonstrated by the decline over the past five years of food borne illness reported by the Centers for Disease Control and Prevention (CDC)."
