Staph on the March

More and more, the four scariest letters for parents and students across the country are MRSA, for methicillin-resistant Staphylococcus aureus. Over the past month, schools have shuttered their doors, sanitized their hallways and alerted parents to the presence of the spreading drug-resistant bacteria in locker rooms and on wrestling mats. At least three students have died of the infection. Headlines have alarmingly--if predictably--cried out warnings of a superbug, and there is in fact cause for real worry.

Unlike severe acute respiratory syndrome, or SARS, which emerged with a deadly energy in 2003 and caught health officials by surprise, MRSA isn't exactly a new bug making its first appearance in human hosts. Since the 1960s, hospitals have been battling the staph pathogen--something to be expected in institutions that are, by definition, gathering places for the sick. What is upsetting about the recent reports is that they are coming from outside the hospital, confirming that drug-resistant strains of the bacteria are finding new homes in the community--particularly among kids.

Most cases of MRSA outside health-care settings are mild, appearing as red, swollen pustules on the skin, and can be controlled with antibiotics other than ones from the penicillin family. These cases are usually not the so-called invasive infections--those that enter the bloodstream and can damage tissues. Last month, however, the Centers for Disease Control (CDC) and Prevention released a report on invasive MRSA estimating that in 2005, there were 32 cases per 100,000 people in the U.S.--a troublingly high number--and that 14% of these occurred in people with no documented history of a hospital stay. Because the CDC does not require physicians to report MRSA cases outside hospital settings, this report is the first to establish how prevalent the infections are, and, says Monina Klevens, an epidemiologist at the CDC, "It will be a baseline against which we can compare future numbers."

Experts blame the emergence of these souped-up bugs in part on our habit of treating so many infections with powerful antibiotics; the microbes battle back by mutating to become resistant to the drugs. It's a process that can't be reversed overnight, but there are ways to keep the bugs at bay. Schools and other fertile breeding grounds like health clubs should be kept clean. Adults and kids should stay alert to news of outbreaks. And everyone should take care to keep hands washed and cuts covered. Bacteria can't thrive where they aren't welcome.