Ignoring the evidence on farming

Thursday December 8, 2011

Jason Smith warns that farming policy is following alarmist sentiment rather than evidence, at a risk to public health

“Over-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?

Opponents of intensive agriculture argue that bacteria become resistant to antibiotics in the guts of animals, and humans ingest these bacteria through the consumption of animal products and by drinking water contaminated by ‘run-off’ from factory farms. Soil Association Chief Executive, Helen Browning has said, “We need to get farmers off this treadmill”.

Antibiotics have been used for over 40 years on farms for three main purposes: to treat an identified illness; to prevent illness in advance; and to increase growth rates. The use of antibiotics as growth promoters added to animal feed was banned in the EU, against the advice of the EUs 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 their pre-emptive “prophylactic” use.

But 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 608 million, 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 in the absence of antibiotic-mediated livestock. 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, report 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 lead to higher doses of antibiotics being used overall. The Denmark ban led to an increase in diarrhea in pigs and an increase in deaths by more than 20 per cent according to the World Health Organisation (WHO).

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 Denmark ban, antimicrobial use has increased by nearly 110% while the number of animals has only increased 5%, due to higher dosages being used to treat, rather than prevent.

Since the antibiotic ban pig farmers in Denmark are now utilizing zinc to help control diarrhea in hogs. Ironically it is highly likely that this may be encouraging the incidence of Methicillin Resistant Staph Aureus (MRSA). Most importantly WHO has stated that there has been no evidence of improved public health since the ban. In fact, resistant Salmonella in humans has increased and Denmark has had its largest outbreak of MSRA.

The Denmark 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, face 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. Since an animal cannot be allowed to suffer, the 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 people who would rather food be produced as if we still lived in the Victorian era. It seems that EU agriculture bureaucrats are trying to find some connection with the public by implementing ‘popular’ but counter-productive policies.