WHAT kills more than five times as many Americans as AIDS? Hospital infections, which account for an estimated 100,000 deaths every year.

Yet the Centers for Disease Control and Prevention, which are calling for voluntary blood testing of all patients to stem the spread of AIDS, have chosen not to recommend a test that is essential to stop the spread of another killer sweeping through our nation’s hospitals: M.R.S.A., or methicillin-resistant Staphylococcus aureus. The C.D.C. guidelines to prevent hospital infections, released last month, conspicuously omit universal testing of patients for M.R.S.A.

That’s unfortunate. Research shows that the only way to prevent M.R.S.A. infections is to identify which patients bring the bacteria into the hospital. The M.R.S.A. test costs no more than the H.I.V. test and is less invasive, a simple nasal or skin swab.

Staph bacteria are the most prevalent infection-causing germs in most hospitals, and increasingly these infections cannot be cured with ordinary antibiotics. Sixty percent of staph infections are now drug resistant (that is, M.R.S.A.), up from 2 percent in 1974. . . . Among developed nations, the United States has one of the worst records of curbing drug-resistant infections, according to the Sentry Antimicrobial Surveillance Program, an international effort to monitor drug-resistant germs. In this country, M.R.S.A. hospital infections increased 32-fold from 1976 to 2003, according to the C.D.C.

In the 1980s, Denmark, Finland and the Netherlands faced similarly soaring rates of M.R.S.A., but nearly eradicated it. How? By screening patients and requiring health care workers treating patients with M.R.S.A. to wear gowns and gloves and use dedicated equipment to prevent the spread. The Dutch called their strategy “search and destroy.”

This is a subject that deserves a lot more attention.