Could the Misuse of Medication in Agriculture Lead to a Global Health Crisis?
A world without antibiotics-where common infections have no cure and can kill mercilessly-is a terrifying possibility. In fact the world’s journey towards a ‘post-antibiotic’ era has been described as a ‘global health crisis’ by the World Health Organisation [WHO].
According to WHO director general Dr Margaret Chan: “Medicine is losing more and more mainstay antimicrobials as pathogens develop resistance. Second-line treatments are less effective, more costly, more toxic, and sometimes extremely difficult to administer. Many are also in short supply.
“This will be the end of modern medicine as we know it. If current trends continue, sophisticated interventions, like organ transplantation, joint replacements, cancer chemotherapy, and care of pre-term infants, will become more difficult or even too dangerous to undertake.”
There are a number of reasons behind this growing problem. The over-prescription of antibiotics is one of them, as is the easy access to over-the-counter medicines, according to Dr Chan.
She adds: “Overprescribing also occurs in animal husbandry and agriculture, and in the food industry, especially when massive quantities of antibiotics are used to promote growth, not to treat sick animals.”
The use of veterinary antibiotics is not tracked in detail by the government. The annual tonnage of antibiotics sold for agriculture is known, but not how much of that is used, how many animals are treated, and whether the medication is used for treatment of diagnosed diseases.
This is considered a problem by a number of experts, with Christopher Thomas, professor of molecular genetics at Birmingham University, telling the Guardian: “There a lot of worry about whether we should be using the same antibiotics on a farm as we do in [human] clinics, as the resistance developed on farms could spread to humans. However good your hygiene [on farms], it is inevitable that resistant bacteria bred on the farm will get to humans.”
Dr Chan continues: “Routine use of antibiotics at sub-therapeutic levels kills the weakest bacteria, but lets the more resistant ones survive. Farmers working with cattle, pigs, and poultry infected with drug-resistant bacteria are at much higher risk of being colonized or infected with these bacteria. In addition, human consumption of food carrying antibiotic-resistant bacteria can lead to the acquisition of a drug-resistant infection.”
That is to say, healthy animals are being dosed with medication they don’t need: it is simply being used to stop infection from developing within a herd, or to make them grow faster. Unsurprisingly, both uses are particularly prevalent in intensive agriculture, where animals are kept in confined conditions. In the EU nearly 90 per cent of farm antibiotic use is for group treatments-often for mass medication of pigs or poultry.
Not everyone feels this is a problem in the UK: Peter Borriello is chief executive of the Veterinary Medicines Directorate, the government agency that oversees antibiotic use on farms. He says: “We are not aware of any major resistance problems and not aware of any major changes in veterinary pathogen populations with respect to their resistance potential.”
He also claims people should not be too worried as the UK farming industry is well-regulated and uses fewer antibiotics than other EU countries.
But the WHO is not the only organisation which is worrying about the issue. A report published late last year by an independent committee chaired by British economist Jim O’Neill looked specifically at antibiotic use in the environment and agriculture. It concurred that the use of antibiotics in agriculture is driving up levels of antibiotic resistance-creating new ‘superbugs’.
And, according to some, it’s a situation that’s set to get worse. The report-Antimicrobials in Agriculture and the Environment: Reducing Unnecessary Use and Waste-says as global populations continue to rise and more meat is produced, the misuse of antibiotics will also grow.
Compassion in World Farming [CIWF] is a charity campaigning to end all factory farming. The organisation is currently working on an in-depth project to stop the misuse of antibiotics in agriculture. As part of this campaign, the group has set up the Alliance to Save our Antibiotics [ASOA]. Campaigns, lobbying, and communications specialist Emma Rose says: “The global increase in livestock farming – driven by soaring demand for meat and dairy – has led to huge intensification of agriculture. Pigs and poultry are often kept in crowded conditions where respiratory diseases and other infections are more common and harder to control. Such systems are dependent on antibiotics to keep animals disease-free. For example, practices common in intensive systems, such as the early weaning of piglets, increase risk of stress-related problems like swine dysentery and to mitigate for this piglets often given antibiotic preventatively.
“There appears to be an easy justification that if we do not preventatively treat livestock, disease outbreaks risk impacting welfare and farm profitability. But contrary to claims by some in the livestock and pharma industries, routine antibiotics are not necessary for good animal health. Animals should be kept well through good husbandry, housing and welfare. Livestock farmers must look at ways of reducing dependency on antibiotics and keeping animals healthy without routine treatments. This may require a shift to more extensive systems, which generally require fewer drugs, a move towards genetic selection for natural robustness, and improvements to housing and husbandry.”
The statistics are sobering: the evidence suggests the amount of antimicrobials used in food production internationally is at least the same as that in humans, and in some places is higher. For example, in the US more than 70 per cent of antibiotics that are medically important for humans are used in animals. In addition, some last-resort antibiotics for humans are being used extensively in animals, and there are no replacements currently on the way. This was illustrated by a recent study from China, which identified a gene responsible for colistin resistance in bacteria from livestock.
So what is being done about this crisis?
Emma Rose says: “This is, by many accounts, one of the greatest public health issues of the current time. As human resistance becomes more commonplace, it is increasingly likely that the initial antibiotic chosen to combat an infection will be ineffective.
“This creates pressure to use the last few effective antibiotics, which increases resistance rates to these in turn. Resistance to the carbapenems (the drugs of last resort) increased from about five hospital patients in England to over 600 from 2006-2013. The emergence of resistance to last resort drug colistin in pigs and humans in China threw veterinary prescribing into the spotlight. This is clearly traceable back to the farm, where colistin is widely used. In human medicine colistin has historically been rarely used due to its toxicity, but prescribers are increasingly turning to it as other drugs fail.
“Before antibiotics, five women out of every 1,000 died from childbirth. One out of nine people who contracted a skin infection died, as did three out of ten people who contracted pneumonia.
“British scientists have also estimated the impact of having no antibiotics on patients having a total hip replacement. Infection rates are currently 0.5-two per cent. Without antibiotics, the infection rate is estimated to be 40-50 per cent and 30 per cent of those infected will die.”
The Alliance is now calling for dramatic reductions in farm use of antibiotics an EU-wide ban to routine, purely preventative (prophylactic) dosing of groups of entirely healthy animals. It is also calling for reductions to farm use of the critically important drugs-this would include a ban on the use of modern cephalosporins in pigs and for dry-cow therapy, and a ban on the use of fluoroquinolonesin poultry.
Emma Rose adds: “Finally, we want to see a part of an EU-wide antimicrobials strategy – legislation must be aimed at improving animal health and welfare and ensuring that farm animals are kept in less-intensive conditions.”
According to Emma Rose: “Two related regulations are currently under consideration by the European Parliament. These will determine whether it will remain legal to routinely dose groups of animals via their feed or water. The Alliance has been focusing our lobbying efforts on securing strong support for this. In a plenary session in March, MEPs recently voted overwhelmingly in favour of an EU-wide ban to routine preventative dosing of groups of animals. At the same time, 50 medical experts & scientists across EU signed our letter to EU policy makers calling for a ban to such practices.
“If this proposal is adopted, it will represent a major step forwards in the drive to safeguard our antibiotics for the future. Countries like Sweden, Denmark and the Netherlands, which have already banned preventative mass-medication, have much lower levels of farm antibiotic use. It is vital that Members States now show the political will to make this a reality and address concerns that EU proposals are being watered down (the 2nd regulation appears to have caved to lobbying efforts to all routine use in groups animals where just a few are sick). We will be focusing on ensuring that the proposals are not watered down, and in applying public pressure to those industry bodies who oppose regulations to ban such practices.”