As computers spread throughout hospitals, so do nesting spots for potentially deadly bacteria, a new study finds.

Researchers at Chicago's Northwestern Memorial Hospital say computer keyboards can harbor dangerous germs for as long as 24 hours.

Research teams at the hospital contaminated keyboards with three types of bacteria that can cause life-threatening infections in severely ill hospital patients. They found that the bacteria known as VRE and MRSA survived for at least 24 hours, while PSAE bacteria survived for an hour.

When volunteers tapped a key contaminated with MRSA, the bacteria spread to their hands 92 percent of the time. Contamination rates for lower for the other two bacteria -- 50 percent for VRE and 18 percent for PSAE.

The bacteria are generally harmless to healthy people, although one can cause skin rash, boils and blisters.

The problem is likely to grow as hospitals switch to electronic records. Computers are rapidly spreading throughout hospitals and are increasingly found in patient rooms.

Doctors, nurses and others who come in contact with patients are supposed to wash their hands both before and after touching patients. The lead researcher in the study, Dr. Gary Noskin, says they may also have to wash before and after using the computer.

The results of the study were presented at a meeting in Los Angeles of the Society for Healthcare Epidemiology of America.

Noskin noted that, while the study applies to hospitals, the results also raise concerns for computers in schools and offices. He said sharing keyboards could spread cold and flu viruses, although this has yet to be proven in a controlled study.

Also unclear is the best procedure for disinfecting keyboards.