Anti-humans

Time for an injection of common sense

Groups opposed to modern agriculture are using scare stories to try to have antibiotics banned on farms.

by Jason Smith 

‘A world without effective antibiotics is a terrifying but real prospect. Now, the situation is so acute that the director-general of the World Health Organisation, Dr Margaret Chan, has warned of “a post-antibiotic era, in which many common infections will no longer have a cure and once again, kill unabated”... [O]ver-use of antibiotics in factory farming, especially at low doses over several days, is contributing to the huge threat of a world without effective cures for bacterial infections.’

So said Compassion in World Farming, launching a report last month with two other campaign groups, the Soil Association and Sustain. The report, Case Study of a Health Crisis is part of an ‘Alliance to Save Our Antibiotics’. But does factory farming really threaten human health?

The emergence of antibiotic resistance as a serious problem in human medicine has prompted concerns about the public health implications of antibiotic use in agriculture. Opponents of intensive agriculture argue that bacteria become resistant to antibiotics in the guts of animals that are exposed to routine antibiotic use. Then, humans ingest these bacteria through the consumption of animal products and by drinking water contaminated by ‘run-off’ from factory farms. But is there a basis for these fears?

Antibiotics have been used for over 40 years on farms for three main purposes: to treat identified illnesses; to prevent illness; and to increase growth rates. The use of antibiotics as growth promoters added to animal feed was banned in the European Union, against the advice of the EU’s own Scientific Committee for Animal Nutrition, in January 2006. In a press release from the European Parliament in October, it was argued that the EU should also phase out the pre-emptive ‘prophylactic’ use of antibiotics, too. MEPs agreed that active ingredients used in veterinary and human medicines should be kept as separate as possible to reduce risks of resistance transferring between animals and humans.

Antibiotics are sometimes used to prevent diseases that might occur in a herd or group of animals. In situations where the proportion of animals suffering a disease during a defined period reaches a threshold, all animals in the herd are treated, as the probability of most or all of the animals getting infected is high. However, in animals as in humans, a significant proportion of those treated for infectious disease would recover without antibiotics, so it could be deemed that such use is unnecessary. But does this application of antibiotics create resistance?

According to scientists from the US Center for Disease Control and Prevention and the National Institutes of Health, there is ‘no scientific study linking antibiotic use in food-animal production with antibiotic resistance’. The most thorough study on this topic, from the Journal of Risk Analysis in 2008, concluded that the risk of a human experiencing an infection from antibiotic-resistant bacteria because cattle were fed antibiotics is one in 608million, which means it is over 2,000 times less likely than being struck by lightning.

There is, however, ample evidence to suggest that bacteria - including resistant strains - enter a farm from many different sources and that transmission of resistant bacteria may occur even when livestock are not being given antibiotics. According to the US National Academy of Sciences, humans may acquire resistant infections, via livestock, even if antibiotics are not given to those animals. Epidemiological studies have identified other risk factors for infections in humans, including contact with their own pet dogs and cats. These animals may be treated with antibiotics but are rarely tested as potential sources of human infection.

There is also evidence that the removal of antibiotics from veterinary medicine would cause welfare problems. Recent analysis of antibiotic use on farms in Denmark, where a voluntary ban on the use of antibiotic growth promotants (AGPs) was instituted in 1998, reports that antibiotics are now being used sparingly. Farmers and veterinarians must now wait until animals are exhibiting clear signs of illness before treatment is applied. However, this has led to higher doses of antibiotics being used overall. The Denmark ban led to an increase in diarrhoea in pigs and an increase in deaths by more than 20 per cent according to the World Health Organisation.

It is important to understand that the antibiotics used to prevent disease in animals are not used to treat humans. However, the antibiotics used to treat disease amongst animals are also used to treat humans. The ban actually increases the use of antibiotics that are also used in human medicine. Since the Danish ban, antimicrobial use has increased by nearly 110 per cent due to higher dosages being required to treat, rather than prevent, disease.

Since the antibiotic ban was introduced pig farmers in Denmark have begun utilising zinc to help control diarrhoea in hogs. Ironically, it is highly likely that this may be encouraging the incidence of the so-called ‘hospital superbug’, Methicillin-resistant Staphylococcus aureus (MRSA). Most importantly, WHO stated in 2002 that there had been no evidence of improved public health since the ban. In fact, resistant salmonella in humans has increased and Denmark had its largest outbreak of MRSA in 2008.

The Danish ban may have also contributed to a decrease in the number of farms in Denmark from nearly 25,000 in 1995 to fewer than 10,000 in 2005. Farmers, who were already finding it difficult to make a living, faced the increased cost of cattle lost to illnesses that, in the past, would have been saved by using antibiotics. Antibiotics reduce suffering and distress and speed recovery, and since an animal cannot be allowed to suffer the only alternative is to kill it.

Given that there have been few studies into the link between antibiotic resistance and agricultural use, and that these studies have found no evidence of a link, we might ask what all the fuss is about? But when it comes to modern, highly productive and safe farming methods, evidence is not important to groups - like the disingenuously named Alliance to Save Our Antibiotics - who would apparently rather we used Victorian-era methods for food production. The same evidence phobia seems to have afflicted EU bureaucrats and faceless Euro MPs trying to find some connection with the public by implementing ‘popular’ but counterproductive policies.