The Superbug Threat
There is a certain satisfaction in puncturing the arrogance of experts like W.H. Stewart, the American surgeon-general who declared in 1969 that we “can close the book on infectious diseases.” But restoring some respect for the bugs that bite man is more than trendy revisionism. It’s key to solving the problem of drug-resistant bacteria.
According to a report published in last week’s New England Journal of Medicine, infections by a strain of the intestinal bug salmonella that can be killed only by last-ditch antibiotic therapy are rapidly increasing. Strains of three other life-threatening superbugs are now known to be immune to all antibiotics. This is in large part because farmers, doctors and public health leaders have been overusing antibiotics and underestimating the germs’ resilience.
* Doctors’ offices. A recent study by the federal Office of Technology Assessment found that as many as half of all doctors inappropriately prescribed antibiotics for cosmetic reasons (most commonly to prevent acne) or viral diseases (which antibiotics can’t cure). Physicians also tended to prescribe the latest and most potent antibiotics when older drugs would have done the job, not only wasting the stronger drug but making it more likely that the germ will become resistant to a wide spectrum of antibiotics.
Last year, the Centers for Disease Control launched campaigns in several cities to reduce inappropriate antibiotic use. More of the same, reaching more doctors, is needed.
* Homes. The antibacterial household cleaners now trumpeted on supermarket shelves can also encourage superbugs. And studies show they are unnecessary in nearly all households, the exception being those where someone is convalescing after a hospital stay or where a resident has an immune system weakness. In most cases, ordinary water and soap does the job just as well. The CDC campaign should include consumer education on that point.
* Farms. While the use of antibiotics to treat infections in livestock and poultry is widely recognized as legitimate, their use in animal feed and water to promote growth is hardly essential and possibly quite dangerous. The evidence that antibiotic resistance has spread from animals to humans is limited. But there’s little doubt that “growth promoters,” antibiotics in livestock feed, help foster the development of new strains of superbugs.
That’s why an editorial accompanying the New England Journal of Medicine study recommended that antibiotics be given to animals only to prevent or treat disease and “in a way that does not perpetuate the selection of resistance.” Last week, a British parliamentary committee called for a total ban on the use of antibiotics to speed livestock growth, and the United States should consider a similar step. At the least, some federal oversight should be introduced into the current system, wherein farmers can buy antibiotics without any supervision from regulators or veterinarians.
These steps can reduce the incidence of bacteria resistant to antibiotics, but random mutations that create superbugs will always occur. The battle has to be fought on several fronts. Medicine, for instance, needs more researchers like UC Davis pathologist Naomi Balaban, who recently discovered a way to block the toxins produced by some dangerous bacteria instead of killing the bacteria outright, as most antibiotics do.
Contrary to the surgeon-general’s confident 1969 prediction, it’s unlikely we will ever be able to close the book on infectious disease.
