There is an increasing concern that the overuse of antibiotics in the food supply is a major contributor to the rise in drug-resistant supergerms.
This column is based on a single and quite extraordinary statistic: Food animal production accounts for 70 percent -- 70 percent! -- of the antibiotics used in the United States. That doesn't even include the antibiotics used for animals that actually get sick. That figure is for "non-therapeutic use" such as growth promotion and disease prevention.
The heavy reliance on routine antibiotic use is a byproduct of the way we raise animals for food: packed into dim and dirty enclosures where they live amid their own filth, eat food that they haven't evolved to digest, and are pretty much stacked atop one another. Most human beings I know can hardly spend three hours on a plane without contracting a case of the sniffles.
When you give antibiotics to animals meant to become food, however, you're ensuring that antibiotics end up in the food in low but constant doses. That means bacteria are getting more accustomed to the antibiotics. There's good reason to think that this background exposure to antibiotics is contributing to the startling rise in antibiotic-resistant bacteria. Everything from staph to strep to salmonella is exhibiting uncommon resilience in the face of our latest drugs. A 2003 World Health Organization study (PDF) put it pretty starkly: "There is clear evidence of the human health consequences [from agricultural use of antibiotics, including] infections that would not have otherwise occurred, increased frequency of treatment failures (in some cases death) and increased severity of infections." Even stronger was the title of a 2001 New England Journal of Medicine editorial: "Antimicrobial Use in Animal Feed -- Time to Stop."
Rep. Louise Slaughter (D-N.Y.) is a former microbiologist who has a master's degree in public health. She also happens to chair the powerful House Committee on Rules. "This is terribly important," she says. "If people don't believe in evolution, they should look at staphylococcus. Your body used to be able to take care of it. But now it can kill you. It's evolved." Her answer is H.R. 1549: the Preservation of Antibiotics for Medical Treatment Act of 2009. The legislation's approach is very simple, Slaughter says: "The bill preserves the seven most effective classes of antibiotics for human use only. They can be used to treat sick animals, but they can't be used to simply raise animals."
The reason that hospitals seem to be hotbeds for resistant MRSA is because so many different strains are being thrown together with so many doses of antibiotics, vastly accelerating this natural selection process.
Doctors are being advised not to prescribe antibiotics for colds, sore throats or ear infections. In most cases these illnesses clear up on their own and complications are rare. So if your doctor is following the guidelines, you probably won't be prescribed antibiotics for these mild illnesses.
However, doctors and patients only account for about one-quarter of antibiotic use. Further, little-to-nothing is being said of the use of antiviral drugs in our food supply. Considering that antibiotic-resistant strains such as MRSA are believed to have developed from the overuse of antibiotics in animal farming, should we not also look at whether the increased use of antivirals has led to the development of drug-resistant viruses such as H1N1?
Edgar, who is 5, (not 4 as government officials previously reported) is the earliest known victim of the disease in Mexico. How he contracted it could be a key clue in figuring out the disease's path.
Maria del Carmen Hernandez, Edgar's mother, said her son began sniffling and feeling feverish in late March. She gave him flu medicine from the local pharmacy, but the fever didn't go away. She put wet cloths on his forehead. She considered putting him in a tub of water...He had been infected by the swine flu strain, said Dr. Miguel Angel Lezana, head of the national Epidemiological Vigilance and Disease Control Center.
...Investigators are working on two hypotheses, Lezana said. La Gloria is near a huge pig farm, and residents have long complained that the agribusiness is contaminating their soil, water and air...La Gloria and surrounding parts of Veracruz are also home to many migrant workers who travel back and forth between Mexico and the U.S. Officials there have said one outbreak of flu started when a migrant returned from the U.S. and infected his wife, who in turn infected several women in the town.
The question should be asked whether antiviral drugs such as amantadine were given to the hogs in La Gloria.
Downwind of Xaltepec - where 15,000 squealing hogs are squeezed into 18 warehouses - residents of La Gloria blame Smithfield, Luter's firm, for an outbreak of respiratory problems that swept the town last month, killing two children. Now with Mexican authorities identifying a four-year-old from the town, Edgar Hernandes, as one of the first-known cases of swine flu, furious residents believe that they are ground zero of a pandemic threatening the world. The very suggestion has sent a shudder through the ranks of campaigners who have long argued that the sort of industrialised pig farming that has turned Smithfield into one of the most powerful corporations in the US, with a market value of $1.4bn, was a disaster waiting to happen.
China's use of the drug amantadine, which violated international livestock guidelines, was widespread years before China acknowledged any infection of its poultry, according to pharmaceutical company executives and veterinarians.
...Although China did not report an avian influenza outbreak until February 2004, executives at Chinese pharmaceutical companies and veterinarians said farmers were widely using the drug to control the virus in the late 1990s.
The Chinese Agriculture Ministry approved the production and sale of the drug for use in chickens, according to officials from the Chinese pharmaceutical industry and the government, although such use is barred in the United States and many other countries. Local government veterinary stations instructed Chinese farmers on how to use the drug and at times supplied it, animal health experts said.
Amantadine is one of two types of medication for treating human influenza. But researchers determined last year that the H5N1 bird flu strain circulating in Vietnam and Thailand, the two countries hardest hit by the virus, had become resistant, leaving only an alternative drug that is difficult to produce in large amounts and much less affordable, especially for developing countries in Southeast Asia.
The bird flu was shown to become amantadine-resistant after its use on livestock. If antivirals were used on pigs, we might expect the swine flu to become resistant to amantadine as well. This is precisely what has happened.
The other big piece of news is this: the [swine flu] virus' genetic profile means it is apparently resistant to a cheap, commonly-used flu drug called amantadine, but responds to two newer antiviral treatments, Tamiflu and Relenza.
Congress should consider legislation such as Rep. Slaughter's HR 1549 to ban the routine use of antibiotics on healthy livestock and amend the bill to add a ban on antivirals for the same purpose.
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