Tuesday, May 19, 1998 Published at 16:16 GMT 17:16 UK
Animals and antibiotics: The dangers
There are fears that feeding antibiotics to farm animals could lead to drug-resistant bacteria being passed on to humans
Animals have had antibiotics included in their feed for about 50 years. It helps to keep them healthy, and it has the added benefit of making them grow faster.
But now a number of organisations, including the World Health Organisation and the European Commission want a ban introduced. In the UK, the House of Lords Science and Technology Committee and the National Consumer Council have also come out against antibiotics in animal feed.
They believe the use of such medicines is unnecessary and poses a serious risk to human health. The great fear is that over-use of the medication will lead to the development of drug-resistant pathogens getting into our food.
The arguments against growth promoters:
The continued use of growth promoters - low-dose antibiotics placed in livestock feed - risks the development of antibiotic-resistant bacteria which could threaten human health, opponents argue. The rapid reproduction of bacteria means there is always a chance that a population of microbes will develop which is antibiotic resistant.
Continued use of an antibiotic only accelerates the success of the pathogen. This could endanger the health of humans directly if the bacteria got into food. In theory, disease could also spread if the animal microbes pass their drug-resistant genes to human bacterial strains.
The UK Government was sufficiently concerned about the problem to ban the use of human antibiotics as animal growth promoters. But this move is only likely to prove effective in the short-term. Although few pathogens can survive in both an animal and a human host, there is laboratory evidence that resistance can be passed across the species barrier through meat products.
Of particular concern has been the use of avoparcin as a growth promoter. It is known to confer cross-resistance to a class of related antibiotics, including the human drug called vancomycin. This has become a vital, "last resort" treatment in modern hospitals faced with drug-resistant "superbugs" such as MRSA.
Supporters of growth promoters will point to the lack of cases in the field of cross infection or gene transfer. But are the risks worth taking? Is the money saved at the supermarket worth the dangers associated with the development of new "superbugs"?