Older age, nursing home residency increased risk for death from MRSA

Several factors, including older age, residence in a nursing home and severe bacteremia, were associated with increased risk for death among patients with methicillin-resistant Staphylococcus aureus, researchers suggest.

In a retrospective cohort study, researchers from the Rockefeller University, Mount Sinai School of Medicine and Weill Cornell School of Medicine analyzed predictors for risk of death among patients with MRSA in an academic medical center from 2002 to 2007. The study included 699 episodes of MRSA among 603 patients. The researchers obtained patient information from electronic and paper charts of these patients.

The patients had an average length of stay of 32.9 days, and many of the cases occurred in patients with renal insufficiency or cardiovascular disease. More than 40% of patients had recently had a surgical procedure and 43% of the cases were secondary to infections related to central venous catheters. The 90-day all-cause mortality rate was 27.2%.

Fifty-five of the 699 episodes were caused by a vancomycin-intermediate resistant S. aureus strain and 55 of the episodes were caused by a heteroresistant vancomycin-intermediate resistant S. aureus strain. Among the patients, 47% had been exposed to vancomycin, and of these, 60% had a prior MRSA infection. Vancomycin was used to treat 81% of the 699 MRSA episodes.

Cirrhosis of the liver and central venous catheter infections were associated with a nearly doubled risk for heteroresistant vancomycin-intermediate resistant S. aureus infection. A history of vancomycin exposure increased the risk for vancomycin-intermediate resistant S. aureus.

The following factors were independently associated with increased risk for death: older age, cirrhosis, renal insufficiency, living in a nursing home or admission to the ICU. There was a lower risk for death among patients who had diabetes or who consulted with an infectious diseases specialist.

“Our study emphasizes that after a diagnosis of MRSA bacteremia is made, it is crucial to determine patient risk factors and not just the vancomycin MIC for the infecting strain,” the researchers wrote. “The consequences of MRSA bacteremia are clear — many patients will die or experience a decline from their baseline clinical condition.”

References:

Pastagia M. Emerg Infect Dis. 2012;published online ahead of print June 13.

Disclosures:

The researchers report no relevant financial disclosures.

Several factors, including older age, residence in a nursing home and severe bacteremia, were associated with increased risk for death among patients with methicillin-resistant Staphylococcus aureus, researchers suggest.

In a retrospective cohort study, researchers from the Rockefeller University, Mount Sinai School of Medicine and Weill Cornell School of Medicine analyzed predictors for risk of death among patients with MRSA in an academic medical center from 2002 to 2007. The study included 699 episodes of MRSA among 603 patients. The researchers obtained patient information from electronic and paper charts of these patients.

The patients had an average length of stay of 32.9 days, and many of the cases occurred in patients with renal insufficiency or cardiovascular disease. More than 40% of patients had recently had a surgical procedure and 43% of the cases were secondary to infections related to central venous catheters. The 90-day all-cause mortality rate was 27.2%.

Fifty-five of the 699 episodes were caused by a vancomycin-intermediate resistant S. aureus strain and 55 of the episodes were caused by a heteroresistant vancomycin-intermediate resistant S. aureus strain. Among the patients, 47% had been exposed to vancomycin, and of these, 60% had a prior MRSA infection. Vancomycin was used to treat 81% of the 699 MRSA episodes.

Cirrhosis of the liver and central venous catheter infections were associated with a nearly doubled risk for heteroresistant vancomycin-intermediate resistant S. aureus infection. A history of vancomycin exposure increased the risk for vancomycin-intermediate resistant S. aureus.

The following factors were independently associated with increased risk for death: older age, cirrhosis, renal insufficiency, living in a nursing home or admission to the ICU. There was a lower risk for death among patients who had diabetes or who consulted with an infectious diseases specialist.

“Our study emphasizes that after a diagnosis of MRSA bacteremia is made, it is crucial to determine patient risk factors and not just the vancomycin MIC for the infecting strain,” the researchers wrote. “The consequences of MRSA bacteremia are clear — many patients will die or experience a decline from their baseline clinical condition.”

References:

Pastagia M. Emerg Infect Dis. 2012;published online ahead of print June 13.

Disclosures:

The researchers report no relevant financial disclosures.