Pig antibiotic use linked to human antimicrobial resistance
Danish pig producers efforts for reducing antibiotics is a blueprint for global swine sector.
Pig farmers and veterinarians across the globe are feeling the pressure to reduce antibiotic medicines to treat sick livestock after a recent spread of antibiotic resistant diseases in humans across Europe.
Several national health authorities have said they believe the misuse or overuse of antibiotics in animals can be linked to the spread of resistant bacteria affecting humans and fear the threat of untreatable ‘super bugs.’
A recent report commissioned by the Department for Environment, Food and Rural Affairs in the UK pointed to a “slow but insidious growth” of resistant organisms that was threatening to turn common infections into untreatable diseases. The author of the report, clinical microbiologist Professor Peter Hawkey, also warned that what he described as a “worldwide issue” had become medicine’s equivalent of climate change.
Antibiotics in pigs
Although the impact of using antibiotics in pigs on the treatment of human diseases is hotly debated, as pointed out in a paper by James M Tiedje and published by the U.S. National Academy of Sciences, the European Union’s latest action plan against antimicrobial resistance includes several steps that affect the pig and livestock industry.
These include strengthening EU law on veterinary medicines and medicated feed; plans for new tools to tighten prevention and control of infections in animals in a new EU Animal Health Law; and strengthening surveillance systems on antimicrobial resistance and antimicrobial consumption in animal medicines. It is also considering recommendations for “prudent use of antimicrobials in veterinary medicine, including follow-up reports.”
The Danish pig industry has been aware of this challenge for a long time and is leading the way in the pig sector’s fight against antimicrobial resistance. Their campaign could be used as a blueprint to help pig producers in other countries reduce their use of antibiotics without affecting production too much.
In 2000, the Danish authorities established VETSTAT, a central database in which veterinarians and pharmacists had to register all prescriptions of veterinary medicines issued to farmers. This data is then used to issue so-called “yellow cards” to pig producers who are found to be using above-average amounts of antibiotics and they are then required to implement measures to reduce their usage within a certain time.
Danish pig producers have been working closely with the local authorities on ways to reduce the use of antibiotic medicines since 1995, when the industry first came under scrutiny because of a rise of antibiotic resistance in humans. The Danish pig industry agreed to a voluntary ban on the use of avoparcin and virginiamycin as growth promoters and then agreed to stop the use of all growth promoters in 2000, six years in advance of EU legislation.
Laws to stop veterinarians selling antibiotics and to ensure that medicines were prescribed to treat a specific disease identified in a pig herd, rather than used prophylactically were also introduced. And, in 2010, the Danish pig industry agreed to ban the use of cephalosporins, used widely to treat staphylococcus infections in the human population. The Danish government also banned the use of fluoroquinolones.
“Yes, the ban on AGPs did hit pig production and increase mortality among the pigs at first and some pig farmers did go out of business,” says the Danish Agriculture and Food Council’s chief veterinary adviser and antibiotics guru, Dr Jan Dahl. “But, we quickly learned how to manage these new challenges by switching, for example, to all-in all-out systems.”
“Now, after the initial challenges I think the ban was good,” said Dr Dahl. “Although I cannot say that it has made a big difference in human health, it has certainly helped improve the image of the pig industry. It has shown we are prepared to change, if necessary, to help the public and what we have achieved is worthwhile.”
“We are still treating sick pigs, but I believe we are doing it in a more intelligent fashion by treating individual pigs, or pens, instead of whole units. These days we are also focusing much more on the health of the animals and on getting rid of infections, rather than treating them, by encouraging closer cooperation between veterinarians and pig producers,” he said.
“I think another key factor in the success of our campaign to reduce the use of antibiotics was the introduction of the SPF declaration system, which allows potential buyers – and the general public – to obtain information about health of specific pig herds before buying,” said Dr Dahl.
Although this system was introduced some 40 years ago, way before anybody was worrying about antibiotics; Dr Dahl sees it as one of the main reasons for the country’s low usage, because “It encourages farmers to look for pigs with a high health status, to make sure they are not buying in any new diseases.
Balanced antibiotic use
“Such openness and transparency may be something of a cultural shock for some people, but it is a system with strict biosecurity rules that serves us well and has been important in terms of safeguarding the health of our pigs and livestock,” says Dr Dahl.
While extremely pleased with the results of the Danish pig industry’s achievements regarding the use of antibiotics, Dr Dahl was concerned that some of the things that they had done were more for political reasons, than strictly medical ones.
“I think we should work hard to improve our scientific risk assessments, so that we can move away from focusing on the amount of antibiotics we use to looking more critically at which antibiotics really matter and how we can best use them. While I agree that the use of certain antibiotics should be restricted to reduce the risk of increasing resistance in humans, we still need to use others to treat sick pigs,” he said.
“We need to have a much more balanced approach to the use of antibiotics incorporating careful scientific risk assessment, so we don’t end up with rules that are so restrictive it becomes impossible to have profitable pork production, along with good animal welfare,” says Dr Dahl.
“Naturally, I still want Denmark to enjoy competitive pig production and you have to treat sick pigs,” he said. “If we ban all antibiotics, we will have to use some alternative treatments and that could lead to even more dangerous situations.”
A spokesman for the Danish Agriculture & Food Council told Pig International that VETSTAT data confirmed that by November 2011 the Danish pig industry had halved its usage of antibiotics since 1995. It also indicated that the pig sector had one of the lowest levels of veterinary medicine usage among all the major pig producing countries.