van Hal SJ. Clin Infect Dis. 2012;doi:10.1093/cid/cir935.
New findings published in Clinical Infectious
Diseases indicate that increased vancomycin minimum inhibitory
concentration was associated with a higher mortality rate in patients with
methicillin-resistant Staphylococcus aureus bloodstream infections.
“Thus, institutions should consider conducting
Etest minimum inhibitory concentration (MIC) on all methicillin-resistant
Staphylococcus aureus (MRSA) bloodstream infections isolates,”
Sebastiaan J. van Hal, FRACP, FRCPA, of the University of Western
Sydney, Australia, and colleagues wrote in the study.
The study included a systemic review of 22 studies that
included treatment outcomes or mortality associated with vancomycin MIC
conducted between January 1996 and August 2011.
Vancomycin MIC was significantly associated with
mortality for MRSA infection (OR=1.64; 95% CI, 1.14-2.37). This association was
higher in patients with MRSA bloodstream infections (OR=1.58; 95% CI,
1.06-2.37) and isolates with a vancomycin MIC of at least 2 mcg/mL by Etest
(OR=1.72; 95% CI, 1.34-2.21).
In addition, isolates with a vancomycin MIC of at least
1.5 mcg/mL were significantly associated with treatment failure (OR=2.69; 95%
“Although these data highlight concerns about
vancomycin, currently, there are no data to support better survival rates with
alternative antibiotics,” the researchers wrote. “Data are needed to
determine whether other agents can remedy these outcomes observed with
vancomycin for MRSA infections with elevated vancomycin MIC values.”
Disclosure: Dr. van Hal reports receiving grant
support from Gilead, Merck, Novartis and Pfizer.