Saturday, 23 April 2011

MRSA in American meat

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This particular comment about the Danish experience by Dr Scott Hurd has received wide coverage in the USA and abroad as part of the furore following tests suggesting that one quarter of American meat carries antibiotic resistant disease.

Let’s take the definitions, figures and facts un-argued, and just deal with the interpretation.

Let's look at what he had to say, the full article is here,  and comment after.

New study adds to concerns about animal-to-human resistance to antibiotics


Evidence suggests that routine use of antibiotics on animal farms is leading to antibiotic resistance in humans. A look at what's known and what's being done.


Quote


….Denmark, the world's largest pork exporter, has made changes with good results. From 1992 to 2008, antibiotic use in pig-rearing was cut by more than half (as measured per kilogram of pig). During that same period, overall production increased, animal growth rates improved and death rates didn't change, according to a 2010 report in the American Journal of Veterinary Research.

But Dr. Scott Hurd, a trained veterinarian and researcher at Iowa State University in Ames, says industry numbers show that only 13% of antibiotics used in food animal farming are for growth promotion and adds that preventive use is necessary in certain situations. "It's always based on previous experience, when you know the animals are going to get sick," he says. He notes that in Denmark, the amount of antibiotics used for treatment has doubled, indicating that a lot more animals are getting sick.

Hurd adds that changing practice in the name of public health would be counterproductive. "We lose a lot of our tools to keep animals healthy," he says. "Even marginally ill animals are more likely to be contaminated with Salmonella and Campylobacter, so you have the potential to decrease public health."…

Unquote

It was ironic that this should appear in California.

If you are dealing with future events, by their very nature you can’t be sure of outcomes. It is logical and sensible to assume that some “preventative” use of antibiotics was actually unnecessary.

So the condition “…when you know the animals are going to get sick," is obviously not always applicable and antibiotics are sometimes used when not needed.

What the unnecessary proportion may be is a matter for conjecture, but since the benefits of antibiotics are additional growth in healthy animals, it is reasonable to assume that it is high. Judgement in cases of doubt will naturally veer towards what is, from a profit and individual pig point of view, beneficial.

Nobody doubts that the use of antibiotics for growth promotion prevented some illness anyway, so it is entirely logical to assume that the ban on growth promotion would lead to a rise in therapeutic use. The methods of administering medicines to a herd of pigs does tend to make a blunderbuss approach inevitable anyway: the healthy get treated with the ailing.

Danish pigs are sick. Dutch scientists flew to California and told the world about MRSA in pigs in 2003, even before peer review, desperate to ring the alarm balls.

The writer helped publicise their disclosures in Britain and suffered a barrage of organised libellous abuse.

The world did not listen: they did not want to hear.  Now pigs all over the world are desperately sick with viral disease and resulting co-infections resistant to some antibiotics.

Of course antibiotic use for therapeutic use has risen in Denmark, even though the total use has declined very sharply: a success, not a failure.

The Dutch disclosure and Danish actions took a lot of guts and integrity, the last for a country that lives off the back of a pig.

There are good reasons to believe that they spoke out when others, with even sicker pigs, stayed silent.

We should listen to the Danes, not draw the wrong conclusions from their efforts to tackle a problem ignored, covered-up or underplayed by the rest. They seem to be doing pretty well given the circumstances.

Excessive antibiotic use in animals, (what is excessive use?) is responsible for much human misery and many deaths. It has to be tackled.