Researchers say nearly 19,000 people in the United States died in 2005 after being infected with a drug-resistant bacteria.
The findings appear in the Journal of the American Medical Association. The Centers for Disease Control and Prevention led the study.
It looked at nearly 9,000 cases of the infection and 1,600 in-hospital deaths among patients infected with the bacteria, called methicillin-resistant Staphylococcus aureus (MRSA).
The researchers estimate that more than 94,000 people in the United States were infected with the bacteria in 2005, and that those infections were associated with 18,650 deaths. They say most of the infections were associated with health care treatment and facilities, including hospitals and nursing homes.
But the researchers say they surveyed largely urban areas and that the number of cases of invasive MRSA may be overestimated. They also caution that it is possible that the bacteria may not have caused or contributed to some of the deaths.
Some information for this report was provided by AFP, AP and Reuters.