Two days ago, The Age published an article with the headline “The superbug that could render antibiotics useless just hit the US”. This superbug is resistant to colistin, one of the strongest antibiotics. Colistin-resistent bacteria have also been identified in China, Canada and Europe. Meanwhile, St Vincent’s Hospital in Melbourne is reportedly screening patients for antibiotic resistant bacteria called Carbapenem Resistant Enterobacteriaceae (CRE). These bacteria can kill half the people they infect.
Antibiotics are used to treat bacterial infections in humans and animals. In animals used for food they are also commonly used to prevent infections. In factory farming animals are regularly fed antibiotics in sub-therapeutic doses, that is in doses that are lower than those required to treat infections. These low doses are particularly likely to lead to the development of resistant bacteria. Antibiotics are also used to a lesser extent for growth promotion in animals. The extensive and routine use of antibiotics in human and non-human animals has contributed to the emergence, persistence and spread of resistant bacteria.
Resistant bacteria in food-producing animals are of concern because, through the consumption of animal foods, they can directly or indirectly result in antibiotic resistant infections in humans. From the factory farm, they also spread via water, air and manured soils. Meat labelled as “organic” or “antibiotic-free” is not necessarily safe. For example, a study from the US found that
… regardless of product type, fresh retail chicken breast is commonly contaminated with enteric pathogens associated with foodborne illness and commensal bacteria harboring genes conferring resistance to critically important antimicrobial drugs.
(The term “antimicrobial” refers to a group of organisms that include bacteria, parasites, viruses and fungi.)
Humans do not routinely take antibiotic drugs for the prevention of diseases. So why should this be necessary for farm animals? Most of the 500 million farm animals we eat every year in Australia live in such overcrowded and unhygienic conditions that they are prone to infections. It is cheaper to feed antibiotics than improve the animals’ living conditions.
On average, 587 tonnes of antimicrobials were sold annually in Australia for veterinary use over the period 2005-2010. Ninety-eight per cent of this was for food producing animals. The percentage used for growth promotion was around 4% (23.5 tonnes).
The public health threat of antimicrobial resistance (AMR) has been recognised for some time. While AMR had been observed for the first time only a few years after the discovery of antibiotic medicine in the 1940s, it has developed into a global threat over the last two decades.
According to the World Health Organization
AMR makes it difficult and more expensive to treat a variety of common infections, causing delays in effective treatment, or in worst cases, inability to provide appropriate therapy. Many of the medical advances in recent years, such as chemotherapy for cancer treatment and organ transplantation, are dependent on the availability of anti-infective drugs. The predictable consequence of resistance is increased morbidity, prolonged illness, a greater risk of complications, and higher mortality rates. The economic burden includes loss of productivity (loss in income, diminished worker productivity, time spent by family) and increased cost of diagnostics and treatment (consultation, infrastructure, screening, cost of equipment, drugs). Both the health and economic consequences of AMR are considerable and costly but difficult to quantify precisely as the available data are incomplete in many countries. The additional human burden associated with it (pain, change in daily activities, psychosocial costs) is also significant, but even more difficult to quantify.
The Australian Government released its first National Antimicrobial Resistance Strategy (2015-2019) last year. The Strategy observes that antimicrobial resistance “affects everyone, regardless of where they live, their health, economic circumstances, lifestyle or behaviour”. It affects human health, animal health, agriculture and food production.
The Strategy points to a “significant knowledge gap” in understanding the extent of resistant bacteria in the food chain and the risks they present. But why would there be a knowledge gap? Perhaps our Government has not made sufficient resources available to research this problem?
Overall, the focus of the Strategy, as far as animal agriculture is concerned, is on education and training, surveillance, research, partnerships and collaboration.
In November 2015, 170 representatives from the human health, animal health and agriculture sectors met in Canberra at the National Antimicrobial Resistance Forum to discuss collaboration in implementing the Strategy. Participants noted that animal health and agriculture initiatives, including livestock and wildlife, were underrepresented in antimicrobial resistance related activities.
In contrast, a recently released report commissioned by the UK Prime Minister calls for the reduction of unnecessary use of antimicrobials in agriculture and their dissemination into the environment. In the report, “unnecessary” is understood to mean any use that is not meant for the treatment of sick animals.
Further, the report seeks restrictions on certain types of highly critical antibiotics, the so called last-line drugs for humans that are currently also used in agriculture. And it demands more transparency from food producers on the antibiotics used to produce meat, to enable consumers to make more informed purchase decisions. It will be interesting to see what action the UK Government takes in response to this report.
It looks like we can’t expect the Australian Government any time soon to remedy the dreadful living conditions imposed on animals we use for food, which would reduce the “need” for the widespread use of antibiotics. The main political parties keep ignoring the urgency of this public health and animal welfare issue, and only the Greens Party and the Animal Justice Party call for an end of intensive factory farming.
While our Government is dithering and hoping for the development of new vaccines, wouldn’t it be prudent to reduce our consumption of animal foods? Even better, stop consuming meat and other animal products. This would also be kinder to the animals and more environmentally sustainable.
Antibiotic resistance. The grim prospect (21 May 2016) The Economist.
Society must seize control of the antibiotics crisis (25 May 2016) Nature.
Use of antibiotics in agriculture expected to skyrocket worldwide (23 March 2015) HealthLine.
Treating cattle with antibiotics affects greenhouse gas emissions, and microbiota in dung and dung beetles (25 May 2016) Proceedings of the Royal Society of London B: Biological Sciences.