As worries rise about antibiotic-resistant superbugs, vets are asking for MPI’s help, reports Eloise Gibson
Vets say it would be easier to safeguard precious antibiotics if regulators listened to them and banned drug companies from marketing straight to farmers.
Farmers in New Zealand, the United States and the United Kingdom have been buying more drugs from the select few groups of medicines people want to keep as last-ditch protection from superbugs. In some cases these include classes of drugs New Zealanders can get from doctors only in special cases.
There are strong pragmatic reasons for farmers to ask vets for drugs like ceftiofur, a third generation cephalosporin, or medicines from another class, called macrolides.
The antibiotics are powerful and clear from an animal’s body quickly, so, for example, a dairy farmer doesn’t need to throw away any milk.
But they are also among the top few classes of antibiotics that the World Health Organisation wants to reserve for treating difficult, life-threatening or multi drug-resistant infections in people.
Sales of macrolides and cephalosporins rose on New Zealand farms from 2009 to 2014, the period covered by the Ministry for Primary Industries (MPI) 2013 and 2016 Antibiotic Sales Analysis reports, although MPI says cephalosporins still make up only about 4 percent of antibiotic sales.
Vets are trying to get better information about which animals specific drugs are being used for, and say the picture may look better when more recent figures come out.
Farmers in the United States – one of the few other developed countries to allow direct advertising – have also been buying more new-generation cephalosporins, earning one ceftiofur manufacturer an estimated US$300m a year.
New Zealand vets have asked MPI to ban antibiotic makers from advertising directly to farmers, saying the ads can put added pressure on vets to dole out precious classes of medicine for the wrong reasons.
Callum Irvine, the head of veterinary services for the New Zealand Veterinary Association, says New Zealand is one of only a few developed countries that allows advertising of antibiotics directly to the end user, and the ads often target dairy farmers. “We believe there is no need for advertising to the end user in New Zealand, when the prescribing and dispensing decisions are made by the veterinarian,” he says. “Our concern is that this advertising may lead to pressure on vets to prescribe antibiotics on the basis of reduced withholding times (from milking) or convenience of use.”
No decision
MPI says it hasn’t yet decided what to do.
In 2013 the ministry said it was looking at controls around antibiotic marketing to see if changes were needed. That was in response to evidence of rising sales in some of the most critical classes in its first comprehensive report on antibiotics in animals.
Yesterday Allan Kinsella, MPI’s director of systems audit, assurance and monitoring said MPI “had initiated a discussion with key stakeholders regarding advertising of antibiotics.
“MPI is considering key stakeholder feedback, but at this stage no decision has been made,” said Kinsella, in an emailed statement.
Kinsella says MPI has stepped up its reporting of antibiotic sales to farmers, so the figures will soon be available yearly instead of every three years.
The latest available figures end at 2014. The vet industry says when more recent numbers are published, they should show critically important antibiotic sales falling. The industry brought in policies after 2014 discouraging vets from prescribing so-called “red light” medicines like macrolides and cephalosporins.
Vets and MPI are trying to get better information about which animals specific drugs are being used for, so they can detect patterns.
At the same time, MPI and the Ministry of Health are developing a national plan on antibiotic resistance, which is due to be finished by May this year. And MPI is developing a work programme on antibiotic resistance, to be finished by the end of this year, which includes a review of registration, classification, labelling and other controls on drugs for animals.
Gatekeepers
Both MPI and vets say animals need to have access to drugs like cephalosporins and macrolides for welfare reasons. Otherwise, they say, some sick animals with treatable but difficult infections may suffer.
Like doctors, vets are the gatekeepers of the most important groups of antibiotics, which the World Health Organisation is counting on to keep people safe while they try to speed new drug development.
While vets are supposed to only dispense the medicines for very difficult infections, sales of ceftiofur grew 118 percent between 2009 and 2011 and a further 56 percent between 2012 and 2014. When MPI asked vets about the trend, vets told the ministry the drugs were being marketed directly to farmers as cheaper and more convenient than using other, older antibiotic classes.
MPI figures showing the total quantity of antibiotics sold for animals rose by 13 percent from 2011 to 2014, to 64,400kg, and cephalosporins (including third generation ones) accounted for 2,300kg of that and macrolides 8,100kg.
Back in 2005 the Expert Panel on Antibiotic Resistance told the Ministry third generation cephalosporins should only be available for animals with “life-threatening conditions” and where lab cultures showed “evidence of unique clinical value”. The same panel report said the use of macrolides and similar drugs in cattle should be discouraged.
Globally, vets and doctors alike are alarmed about antibiotic resistant bugs, which one British study estimated may kill more people worldwide than cancer by 2050.
The contributing factors are over-prescribing to people, routine use on farms (especially overseas), and a lack of new drugs in development.
In New Zealand, antibiotic use on farms remains low by international standards, especially compared to more industrialised farming nations such as the United States and Britain. We also have low levels of antibiotic-resistant bugs, although experts warn that could change quickly. By contrast, New Zealand people are among the higher users of antibiotics in the world.
One exception may be third and fourth generation cephalosporins, which New Zealand GPs are advised not to give to people with routine infections, like chest infections, unless other treatments fail. Humans who need them usually have to visit a hospital pharmacy. Last year the Institute of Environmental Science and Research did not include the drugs in its 2006-2014 antibiotics surveillance report because GPs so seldom prescribe them.
Overseas, vets’ appeals for regulatory help to curb advertising have not always succeeded.
Only a few developed countries allow direct advertising to farmers, including Britain, the United States and New Zealand.
All three countries have seen an upward trend in sales of new-generation cephalosporins and other ‘last resort’ drugs like macrolides.
In 2011, British regulator Defra disappointed vets by denying a request from the British Veterinary Association to ban advertising of critical antibiotics to farmers, despite data showing increasing sales. Britain is the only country in Europe that permits direct advertising of the drugs, but Defra told the Independent newspaper it didn’t need to act because “farmers were experts in rearing livestock and could understand the issues”.
The Independent reported the same year that cephalosporins and macrolides had increased in use by up to eightfold in animals over the previous decade.
Reporting by Reuters shows there is growing alarm about overuse of ceftiofur in the United States, where direct advertising is also allowed.
A report two years ago found the product was being used in sick dairy cows close to the time of slaughter to keep them alive until they could be sold for meat, leading to traces in the food chain and creating a risk to human health from antibiotic resistance. The product was also being used in dairy cows because it doesn’t show up in milk.
The U.S. Food and Drug Administration cautioned in 2012 that ceftiofur could pose a “high public health risk”. Records kept by the U.S. Department of Agriculture and obtained by Reuters showed traces of ceftiofur were found at illegal levels in slaughtered animals more frequently than with any other drug. The ceftiofur residues are not themselves considered dangerous to people who eat the meat, but the traces serve as a warning sign that the drug was used shortly before the animal was killed. Like MPI, FDA requires farmers to obtain a prescription from a veterinarian. Meanwhile, Reuters says, the boom in ceftiofur sales earned its largest maker, a New Jersey-based company called Zoetis, about $300m in revenue a year between 2011 and 2014.
