By world standards Australian agriculture has a remarkably clean bill of health, but a global blowout in resistance to antibiotic medicines has triggered a rush of activity to learn more about the superbug threat and how to stop it.
Livestock industries are part way through a national audit of antimicrobial resistance (AMR) and antibiotic use in animals raised for food production.
Globally at least 700,000 human deaths a year are attributed to resistance to antimicrobial drugs prescribed to treat infections.
The problem is not just an emerging healthcare crisis in Asia and the subcontinent, even the US and Europe annually record about 50,000 deaths following infections which cannot be cured by antibiotics.
By 2050, unless antibiotic use is better managed, the British government forecasts 10 million people will die annually because of resistance issues – about 2m more than the forecast death toll from cancer.
The problem is exacerbated by a decline in research into antibiotics.
“As bacterial infection grows more resistant to antibiotics, companies are pulling out of research and fewer new antibiotics are being approved,” said consulting veterinarian to University of Sydney and numerous animal industry bodies, Stephen Page.
He said the number of global companies researching antibiotics fell from 18 to just four in the 20 years to 2010.
Farm antibiotic use has also fuelled the problem, particularly in Asia where potent antimicrobial drugs are routinely available as preventative treatments in crowded, dusty or disease risky environments, and to treat sick livestock.
A post-antibiotic era?
The World Health Organization (WHO) has warned livestock antibiotic use has heightened the likelihood of a “post-antibiotic era”.
Some food companies, including US giants McDonald’s and Domino’s Pizza, have already responded by introducing policies requiring livestock industries, particularly intensive farms, to limit antibiotic use.
Australian farmers rate near the bottom of international comparisons on annual antibiotic use, at 13.7 milligrams per population correction unit (PCU) – a scale taking into account an animal’s average weight when treated with a drug.
Mr Page said that compared with as much as 370mg/PCU in Italy, 114mg/PCU in the Netherlands, or 51mg/PCU in the UK where antibiotic use is considered relatively modest.
The few therapeutic antibiotics used to treat Australian layer hens for health and welfare reasons do not include the class of antimicrobials critically important to humans
- Rowan McMonnies, Australian Egg Corporation
But while our agricultural antibiotic use is restricted, including bans on drugs used on US and European farms, Australians generally are now among the highest antibiotic consumers in the OECD.
“Warnings about overuse seem to have been ignored, despite human antibiotic use going down for a while – nationally it’s been rising for a few years,” Mr Page said.
In 2014 Australians gained prescriptions for antibiotics at the rate of 125,119 for every 100,000 people, with Queenslanders leading the pharmacy run at 132,730 for every 100,000.
Victorian poultry industry consultant veterinarian and University of Melbourne senior researcher, Dr Peter Scott, said travellers should note just how close to home AMR problems were, given the use of antibiotics in livestock producing the food served in Asian tourist resorts, restaurants and bars.
“An egg is an ovary. It’s a good example of where antibiotics do accumulate,” he said.
In Australia preventative health measures focused on keeping farm environments clean and healthy, with probiotic preventative treatments now widely used to boost gut health and lift productivity.
“Good animal health in this country starts with good infrastructure and management regimes, including clean, well ventilated intensive livestock housing,” Dr Scott said.
Australia’s good story
“The egg industry has a good story to tell and we expect results in the current antimicrobial stewardship survey to confirm this,” said Australian Egg Corporation managing director, Rowan McMonnies.
The federal government-initiated survey is part of Australia’s response to WHO’s global research on antibiotic use and effectiveness.
It has already studied the red meat and pork industries and now centres on poultry and salmon.
“Antibiotic use is tightly regulated and the few therapeutic antibiotics used to treat layer hens for health and welfare reasons do not include the class of antimicrobials critically important to humans,” he said.
Antibiotics commonly referred to as growth promotants were not used in Australian egg farming.
However, Mr McMonnies said the poultry industry could not be complacent given growth in free-range and non-cage egg farming exposed hens to open environments which may contain pathogens and opportunities for native birds to introduce diseases and intestinal pests.
Therapeutic antibiotics would need to be used strategically to ensure the welfare of layer hens which became ill.
Andrew Marshall
Andrew Marshall is the group agribusiness writer for ACM's state agricultural weeklies and websites. He is a former editor at The Land and has worked in various Rural Press group roles in Canberra, North Richmond (NSW) and Toowoomba (Qld).
Andrew Marshall is the group agribusiness writer for ACM's state agricultural weeklies and websites. He is a former editor at The Land and has worked in various Rural Press group roles in Canberra, North Richmond (NSW) and Toowoomba (Qld).
