Contaminated machines in ORs linked to patient infections

Health officials are warning that small outbreaks of infections spread by contaminated operating room machinery during open-heart surgery could be more widespread than first thought.

The Centers for Disease Control and Prevention alerted doctors and hospitals on Thursday. The contamination has been tied to 28 cases in the U.S., including at least four who died. But officials think hundreds or thousands of other patients could have been infected.

The outbreaks have been tracked to certain heater-cooler devices, which are used to keep patients' hearts cold and bodies warm during some heart operations.

The manufacturer of the devices identified the contamination in its factory in Germany in 2014 and reportedly cleaned it up. But bacteria traced to the machines were linked to clusters of illnesses in Switzerland, Pennsylvania, Iowa and Michigan.