Superbugs are here. Microbes vanquished for decades are slowly mutating to resist our pharmaceutical defenses. In U.S. hospitals, bacterial infections sicken almost 2 million people a year and kill 90,000. In more than 70 percent of afflicted patients, the bacteria have become resistant to one or more antibiotics. More ominously, drug-resistant strains that were formerly found only in hospitals have cropped up in community settings, such as schools, jails, and Army training centers.
A more recent threat, HIV, continues to mutate toward drug resistance. Some studies suggest that 10 to 20 percent of newly infected patients in the United States are resistant to at least one HIV drug, and a rare, multidrug-resistant strain cropped up in an infected man in New York City in 2005. Strains of drug-resistant tuberculosis are on the rise in Eastern Europe and Central Asia, and malaria has roared back as one drug after another has become ineffective against the parasite. The World Health Organization General Assembly recently named drug resistance in microbes as one of the top three threats to global health.
Resistance is not confined to human pathogens. The new strain of avian flu that has infected more than 100 people in Asia, and killed more than half of them, may become the next great pandemic. One way to slow its spread is to treat infected birds with amantadine, an antiviral drug meant for humans. But Chinese farmers seem to have used the drug so widely and indiscriminately that a drug-resistant flu strain has developed in some birds, rendering the treatment useless in certain regions.
So far, this avian virus cannot easily infect humans and is contracted only through close exposure to infected birds. But without an effective drug to combat avian infections, more flu-infected birds will come into contact with people, adding to the risk of a mutation that will allow a human-to-human transmission of the flu.
