In a surprising, good-news development, the rate of dangerous staph infections has dropped dramatically in U.S. hospital intensive-care units, a new report finds.

The results may be evidence that some hospitals are finally getting a leg up on deadly drug-resistant germs, through increased vigilance and sanitation.

The U.S. Centers for Disease Control and Prevention report found that rates of infection by methicillin-resistant Staphylococcus aureus, known as MRSA, caused by IV tubes fell nearly 50 per cent in intensive-care patients between 1997 and 2007.

In 1997, there were an estimated 43 MRSA infections for every 100,000 intensive-care patients who spent a day hooked up to an intravenous tube. By 2007, that number dropped to just 21, the report published in the Journal of the American Medical Association found.

A CDC team led by Dr. Deron Burton studied hospital data on blood infections caused by central line catheters, which are tubes inserted into an artery near the heart to deliver medicine or monitor vital signs.

The study authors say the results are likely a sign that hospital workers are working harder at prevention efforts, through frequent hand-washing, instrument sterilization and other measures.

But they point out that while the actual number of MRSA cases fell by half during the study period, the overall percentage of infections caused by MRSA increased.

Of a total of 33,587 central line catheter blood infections, seven per cent were drug-resistant strains of MRSA, while 4.7 per cent, were more easily treatable staph infections.

Drug-resistant bacteria are a growing problem in hospitals worldwide, including Canada. Among the most dangerous is MRSA, a strain of bacteria that can't be treated with common antibiotics. The germs can live on surfaces for days and become deadly once they enter the bloodstream.

MRSA bacteria can't be treated with common antibiotics and cause thousands of serious infections nationwide each year.

According to the Public Health Agency of Canada, hospital-acquired infections result in between 8,000 and 12,000 deaths in Canada each year.

A study release late last year found that rates of hospital-acquired MRSA infections more than doubled in Canada between 1999 and 2005.

There were 5.2 cases per 1,000 hospital admissions in 2005, up from two per 1,000 in 1999. There was also an upward trend in C. difficile infections, while the number of hospitals reporting new cases of vancomycin-resistant Enterococcus (VRE) infection rose 77 per cent over the period.

The report on these recent U.S. figures addressed only infections in intensive-care units; it's unclear whether MRSA infections have declined in other hospital settings, said editorial author Dr. Michael William Climo, an infectious disease specialist at a Hunter Holmes McQuire Veterans Affairs Medical Center in Richmond, Va.

"Despite this progress, most ICUs are far from the goal of zero infections and many have not implemented suggested prevention strategies," he wrote.