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The Global Threat to Human Health

The Global Threat to Human Health

In November 2015, scientists at South China Agricultural University carrying out routine surveillance of bacteria from farm animals noticed a major increase in resistance to the little-known antibiotic, colistin.

They investigated further and what they found stunned the scientific world and led to headlines about how modern medicine was losing its most precious resource – antibiotics – due in part to their overuse in intensive livestock farming.

The scientists found that colistin resistance was widespread in E. coli from pig dung and from pork and poultry. They also found resistance in some human infections. Colistin is not used in human medicine in China, but is widely used in animal feed. They determined it was likely that the resistance was spreading from farms to people.

Laboratories in other countries immediately examined their own collections of bacteria. Very soon, colistin resistance was found in Europe, Africa, Asia and America. UK government scientists found resistance in human E. coli and Salmonella infections, and in pigs from two separate farms.

But why the concern about colistin resistance? After all, colistin is very toxic to people’s kidneys, and for decades doctors didn’t prescribe it because less dangerous antibiotics were available. Unfortunately, as safer antibiotics have been used and overused, in both human and veterinary medicine, resistance to them has increased. Worse still, for many infections, there have been no discoveries of new antibiotics in over 30 years.

Colistin is now our last-resort antibiotic. After colistin, the cupboard is bare, with no new antibiotics in the pipeline for treating E. coli and other highly resistant infections. How did we get to this point, and what role has the overuse of antibiotics in intensive livestock farming played?

Farming’s role in this health crisis

cow being injected with antibiotics

Antibiotics are widely used in pig and poultry farming, as they help to control infections that occur frequently in intensive, indoor conditions. Prescriptions are written for entire flock or herd treatments, even if none of the animals are sick. In Europe, about twice as many antibiotics are used in animals than are used in humans.

For certain human infections like Salmonella and Campylobacter, most resistance in human infections is of farm animal origin. For others, like E. coli and enterococcal infections, many scientists believe that farm animals are a source of some of the resistance.

In recent years, new types of superbugs have emerged in farm animals, such as MRSA, Clostridium difficile, a type of highly resistant E. coli called ESBL E. coli, and some highly resistant Klebsiella. Identical or very similar strains of all of these bacteria have also been found in humans, which has led some scientists to argue that the impact of farm antibiotics on human health is larger than previously understood.

The Alliance to Save our Antibiotics


Through the Alliance to Save our Antibiotics, the Soil Association is at the forefront of the campaign for more responsible use of farm antibiotics. We have published numerous reports and hosted media briefings aimed at focusing public attention on the emergence of MRSA, or ESBL E. coli in farm animals, and the potential dangers associated with toxic residues in meat and eggs.

The Alliance builds the case for high welfare, sustainable systems, and engages the farming industry and government with the opportunity they present.

Seizing opportunities

The emerging crisis of antibiotic resistance is a huge threat to animal welfare, and at the same time is one of the greatest opportunities we have to improve it radically.

As public understanding of farming’s role in antibiotic resistance grows, unprecedented political pressure will be placed on the livestock industry to change farming systems. Yet this opportunity hangs in the balance. Other countries, such as the Netherlands, are realising the massive problem we have on our hands, but are only working to clean up their acts within the current system. This means the same animal factories but with stringent processes in place to make them cleaner. While results have been promising in terms of reducing the amount of antibiotics used, these are still the same intensive environments, with the same numbers of animals packed into indoor boxes, only turned sterile. A boring, unkind and artificial life for animals.

Providing a good life for animals, where they have plenty of space to roam and dig around outside, developing natural resistance to bacteria, and where they aren’t packed in tightly together, reduces the risk of infection and therefore the need for prescribing antibiotics pre-emptively.

We are making the case for better animal welfare through natural methods but we must move quickly to gather data on antibiotic use on organic farms, so that we can use our results to lobby and campaign.