In the UK, 44% of antibiotics are prescribed to non-humans – that’s livestock, including gamebirds, (37%) and pets (7%)1. That’s not to say there are likely to be antibiotics in your meat, there is a mandated withdrawal period before any animal is slaughtered for meat or before milk enters the food chain. However, the overuse of antibiotics as a cause of antibiotic resistance applies as much to veterinary use as for human use. Despite the emergence of antibiotic resistance shortly after the discovery of antibiotics in the 1940s, and many reports in the 1960s and 1970s, it wasn’t until 2006 that the use of antibiotics as growth promoters was banned in the EU. The good news is that government targets to reduce antibiotic use in livestock are currently on track. The bad news is that they are finding antibiotic resistant genes in meat around the world.
The Guardian recently reported on an increase in the proportion of chickens found in UK supermarkets that had campylobacter resistant to the antibiotics used to treat it. (Campylobacter can cause serious food poisoning in humans.) Whilst there are differences in many of the bacteria that infect animals and humans, there is the potential for resistance to be transferred between species (horizontal transfer) and there are some bacteria that are shared; Salmonella and Campylobacter being two examples.
It is also worth noting that 83 billion tonnes of livestock manure is spread onto land each year in the UK, and in one gram of manure there are 1×1011 bacteria, which means that if just 1% of the bacteria have resistance to antibiotics, then there are more resistant bugs than there are grains of sand going onto UK fields each year.
So, given that it might be a problem, what are the supermarkets doing about it? To date, there are only three supermarkets publishing data on the use of antibiotics in their supply chain; Marks and Spencer, Waitrose and Asda, all seem to have less than the sector average which means someone is using more than average. With the exception of Lidl, all of the supermarkets publish their policy online; many contain the same aims. Most are targeting a reduction in the amount used in their supply chain, although some are only just starting to monitor and establish their baselines. All of them say that they will only allow the use of antibiotics under veterinary supervision. But some of the pledges are not entirely clear; for example, Aldi state on their website that they don’t support the use of antibiotics as prophylactics (used to treat an animal to prevent disease e.g. if others in the herd are ill), but then in their policy they state that prophylaxis is only permitted under veterinary supervision. Sainsbury’s have something similar on their website.
But, most concerning to me is the stand on CIAs – Critically Important Antibiotics – antibiotics important to human health. Only M&S states that they prohibit the use of these, including Colistin, the last resort antibiotic for humans. All of the other supermarkets mention them, but they only go so far as to state that they can only be used as a last resort. Whilst these antibiotics only make up around 1% of the total use in animals, M&S seem to be saying that they don’t need to be used at all. With the first bacon labelled as being raised without antibiotics hitting supermarket shelves2, perhaps change is on the way?