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May 21, 2024
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South Africa reports progress in limiting antibiotic use in animal farming

Imagine this: You have a sudden, virulent, painful infection (think gonorrhoea, meningitis, pneumonia). You are rushed to hospital, in agony, but feel reassured by the prospect of swift treatment. An emergency-room doctor diagnoses the dangerous infection and prescribes a fast-acting antibiotic, immediately administered via a drip. But nothing happens. The drug doesn’t work. Your suffering worsens. The doctor concludes that no available antibiotics will cure you.

This is not a far-fetched scenario – it is happening right now.

new global report says that in 2019, drug-resistant infections were directly responsible for almost 1.3 million deaths and contribute, the World Health Organization (WHO) says, to more than 5 million deaths per year.

The report, from the United Nations Environment Programme (Unep), also estimates that up to 10 million people a year could die by 2050 because of antimicrobial resistance (AMR) – that’s the same as the number of people who died from cancer in 2020.

Limiting the spread of antimicrobial resistance, which is when bacteria become resistant to drugs that previously eradicated them, is critical to preserving our ability to reduce disease, food-safety and food-security risks, and protect the environment.

The WHO has been sounding the alarm on AMR since the early 2000s as one of the world’s top 10 global health problems, releasing a “global action plan” on AMR in 2015.

Now, the new Unep report takes an updated global overview of the issue: Bracing for Superbugs amplifies the WHO’s frequent warnings that AMR poses an urgent and critical threat to animal and plant health, food security and economic development.

Pollution from biological and chemical sources fuels antimicrobial resistance’s development, transmission and spread, the Unep report says, with three sectors in particular driving it: agriculture and food, healthcare, and manufacturing of pharmaceutical and other chemicals.

Globally, the overuse and misuse of drugs – especially antibiotics – in the food chain, and in the pollution from livestock farming (spills of manure and other waste into soil and waterways), is a major contributor to the rapid rise of superbugs.

“What drives resistance is use, overuse or inappropriate use,” says Professor Moritz van Vuuren, vice-chair of the Ministerial Advisory Committee on Antimicrobial Resistance (MAC-AMR), and Emeritus Professor of veterinary microbiology at the University of Pretoria.

“The moment you use an antibiotic, you create the possibility for resistance to develop. So, the more inappropriately you use it, the more you drive resistance.

“There’s always been concern about the quantity of antibiotics used in feed and water of animals … large quantities, and obviously those will contribute to driving resistance.

“But it’s not the main cause of resistance in human pathogens. Those multidrug-resistance bacteria are the result of overuse and inappropriate use of antibiotics in humans.”

University of Cape Town’s Professor Marc Mendelson, MAC-AMR chair and head of infectious diseases and HIV medicine at Groote Schuur Hospital, has said that about one-third to one half of antibiotics used in humans are unnecessary, often for viral infections like flu or bronchitis.

“Antibiotics only work against bacterial infections, not viruses or non-specific symptoms – you can’t fit a square peg into a round hole,” he said.

“All they are doing when misused is to increase resistance and cause unwanted side effects.”

Read more in Daily Maverick: “Ten ways to avoid falling victim to an antibiotic-resistant bacterial infection” 

Why antibiotics in animal farming?

This is amplified in animal use, given the massive scale of it. Nearly three-quarters of all antibiotics used around the world are used on animals grown for food, The Guardian reported in 2019, and they include antibiotics “of last resort” for human use.

In many countries, there is little or inadequate regulation to curb this, but scientists “have struggled to estimate the size of the problem due to a lack of data in most of the developing world”, Guardian environment editor Fiona Harvey wrote.

Why are antibiotics considered necessary in animal farming? It comes down to the high-intensity methods used in commercial farming.

Under pressure for rapid growth and high yields, farmers often keep animals in overcrowded, unhygienic conditions where bacteria flourish, and animals’ immune systems are weakened by stress. Females are often not given enough time to recover between pregnancies, placing further stress on their immunity. And when animals get sick, just like humans, they need treatment.

Mendelson highlights the commercial imperative, though: “The animal protein production industry is often about fine margins, and therefore getting animals to market in the shortest time at a decent size and in optimal health, is a constant challenge,” he wrote in an opinion piece in 2022.

Antibiotics can be used in animal farming in three ways, Van Vuuren explains: To treat an individual animal, to prevent disease spreading within a group, or for the sake of preventing disease in general, even if there are no apparent infections.

This used to mean that antibiotics were used liberally and routinely in animal farming to prevent disease, not just to treat animals that were sick. But scientists are clear about stopping the use of antibiotics as growth promoters and for disease prevention.

Van Vuuren says that South Africa is moving away from that approach.

“There have been huge changes and improvements in South Africa,” he told Maverick Citizen.

“We’re not nearly where we were 10 years ago when antibiotics were used liberally in the feed of production animals. Preventative use is what we’re trying to get away from globally, and very much so in SA,” he says, as well as using antibiotics to promote animal growth.

This is despite the fact that government regulations still do not prohibit the use of antibiotics for growth promotion. (The relevant legislation, from 1947, allows them to be sold to farmers over the counter for use in animal food and water, with no explicit limits on using them for growth promotion.)

However, South Africa’s response to AMR overall – not just relating to animals – is now guided by the South Africa Antimicrobial Resistance Strategy Framework of 2018-2024.

About three years ago, Van Vuuren said, the South African Animal Health Association decided to change the package inserts of their antibiotics “to exclude growth promotion and prophylactic use”.

This was a voluntary act, albeit under pressure from various industry-related sources.

“An antibiotic for use in feed and water will never again be registered in this country with a claim for prophylaxis or growth promotion,” Van Vuuren told Maverick Citizen.

“You can never ‘ban’ the use of antibiotics in animals, because they need it just like humans do, for therapy,” Van Vuuren said.

“But, yes, there will eventually be regulations that will prohibit the use of growth promoters … but it’s already being voluntarily phased out by the industry.”

The next regulatory step, Van Vuuren says, is to place all antibiotic use under veterinary oversight, meaning only vets can prescribe, dispense or administer antibiotics.

Those discussions are going on “as we speak”, said Van Vuuren, who was on his way to a South African Health Products Regulatory Authority meeting on this issue the next day.

But what about the antibiotics used for animal treatment – are we being exposed to those in our dairy products, meat, chicken and fish? Officially, the answer is a clear “no”.

Antibiotics used for animals have what are known as “withdrawal periods”, to which farmers have to adhere (mandated by the same legislation authorising registration of antibiotics).

This means the antibiotics given to an animal take a certain time to get metabolised and work their way out of the system through natural biological processes. Farmers have to wait until this happens before slaughter or milking.

“The residues are essentially non-existent,” Van Vuuren says, describing routine testing procedures performed by commercial laboratories. They are contracted by major dairies, for example, to test every bulk batch of milk delivered to a depot.

“It’s an absolutely routine procedure,” he says.

“Every time milk is collected on a farm, a milk sample is taken in a specific container,” Dr Chris van Dijk, a bovine veterinary specialist, told Maverick Citizen.

Then, when the tankers transporting milk in 30,000-litre tankers (with compartments) are delivered to the depot, samples are taken from each compartment, before the milk is pumped out. If analysis of the samples from each compartment within the tanker shows antibiotic residue, the entire batch is discarded – a huge financial loss for the farmer and a clear incentive to toe the line.

“These tests are highly sensitive and qualitative,” says Van Dijk, naming several antibiotics tested for, “and will demonstrate a positive sample if it is above the defined MRL [maximum residue level as defined by law] for the specific antibiotic”. (The milk is tested at the same time for E. Coli, cell count as an indicator of milk quality, a bacterial cattle disease called brucellosis, as well as for water, protein and fat content.)


Why did antibiotic use in animal farming begin?

The use of antibiotics to promote growth in commercial food animals was approved in the United States in the early 1950s (around the time that intensive animal farming was revving up) as well as to minimise disease.

The European Union banned the use of antibiotics and all related drugs in animal feed for growth-promotion purposes in 2007, and the United States instituted a similar ban in 2017, with antibiotics permitted only for disease treatment or prevention purposes under the supervision of a vet.

China outlawed the use of antibiotic growth promoters in July 2020, after a study indicated the possible transmission of resistant Campylobacter bacteria from pigs to humans, to improve the effectiveness of therapeutic antibiotics

Still, China and the US remain the heaviest users of antibiotics in animal farming, accounting for a large chunk of the three-quarters of total antibiotic use, which is fuelled by increasing meat consumption.

In many developing countries, however, there is no legislation on the use of antibiotics (or antimicrobials, more broadly) in livestock. This means better-regulated countries are not insulated from the risk of antibiotic or antimicrobial resistance.

As Fiona Harvey wrote, pollution from sources in developing countries “can no longer be regarded by the rich world as a faraway and localised problem for poor people”.

AMR can spread quickly, and far – one example reported on in 2019 in the journal Environment International proved that genes associated with an antibiotic-resistant superbug first found in a patient in India in 2007-08, then in surface waters in Delhi in 2010, were later found in the soil of Svalbard in the Norwegian archipelago, in the Arctic Circle.

Four global organisations are spearheading the so-called OneHealth approach: The Food and Agriculture Organisation of the UN, the WHO, the World Organisation for Animal Health and the UN Environment Programme, recognising the interdependence of human, animal and plant health and environment, and proposing a range of coordinated actions.

According to Professor Van Vuuren, South Africa is at the vanguard:

“South Africa is on the front foot in terms of embracing OneHealth – people from the medical, veterinary and environmental ‘compartments’ are working together impressively,” he told Maverick Citizen.

“We’ve made great progress in this country in terms of antibiotic stewardship.”

But, he cautions, “We don’t want to create the impression that AMR is not important – it is still one of the world’s biggest risks to mankind [along with climate change and overpopulation].

“There was a perception about 10 years ago that AMR was 99% because of antibiotic use in animals – but antibiotic use in animal farming is not the most important element. It is a contributor and should be addressed, but both human and animal use contributes equally to driving resistance,” Van Vuuren says.

“Whenever you use antibiotics it contributes to AMR. So, the new mantra is, “how do we diminish the need for AB in animal husbandry?”

“I would like the lay public to understand that, but not to think that there is no control or effort to address this. The one thing that is happening is that antibiotic stewardship is being managed by a great group of professionals who ‘know their onions’, and are doing this according to the book.”

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