A strain of MRSA that causes bloodstream infections is five times more lethal than other strains and has shown some resistance to the potent antibiotic drug vancomycin, says a new study by researchers at Henry Ford Hospital.
In the study, researchers found that 50 percent of the patients infected with the strain died within 30 days compared to 11 percent of patients infected with other MRSA strains.
The average 30-day mortality rate for MRSA bloodstream infections ranges from 10 percent to 30 percent.
The researchers said that the strain USA600 contains unique characteristics that may be linked to the high mortality rate.
However, they also said that it is unclear whether other factors like the patients' older age, diseases or the spread of infection contributed to the poor outcomes collectively or with other factors.
The average age of patients with the USA600 strain was 64; the average age of patients with other MRSA strains was 52.
"While many MRSA strains are associated with poor outcomes, the USA600 strain has shown to be more lethal and cause high mortality rates," said Carol Moore, a research investigator in Henry Ford's Division of Infectious Diseases and lead author of the study.