Methicillin-Resistant <emph type="ital">Staphylococcus aureus</emph> Central Line–Associated Bloodstream Infections in US Intensive Care Units, 1997-2007

Abstract

For editorial comment see p 772. Context Concerns about rates of methicillin-resistant Staphylococcus aureus (MRSA) health care-associated infections have prompted calls for mandatory screening or reporting in efforts to reduce MRSA infections. Objective To examine trends in the incidence of MRSA central line-associated bloodstream infections (BSIs) in US intensive care units (ICUs). Design, Setting, and Participants Data reported by hospitals to the Centers for Disease Control and Prevention (CDC) from 1997-2007 were used to calculate pooled mean annual central line-associated BSI incidence rates for 7 types of adult and nonneonatal pediatric ICUs. Percent MRSA was defined as the proportion of S aureus central line-associated BSIs that were MRSA. We used regression modeling to estimate percent changes in central line-associated BSI metrics over the analysis period. Main Outcome Measures Incidence rate of central line-associated BSIs per 1000 central line days; percent MRSA among S aureus central line-associated BSIs. Results Overall, 33 587 central line-associated BSIs were reported from 1684 ICUs representing 16 225 498 patient-days of surveillance; 2498 reported central line-associated BSIs (7.4%) were MRSA and 1590 (4.7%) were methicillin-susceptible S aureus (MSSA). Of evaluated ICU types, surgical, nonteaching-affiliated medical-surgical, cardiothoracic, and coronary units experienced increases in MRSA central line-associated BSI incidence in the 1997-2001 period; however, medical, teaching-affiliated medicalsurgical, and pediatric units experienced no significant changes. From 2001 through 2007, MRSA central line-associated BSI incidence declined significantly in all ICU types except in pediatric units, for which incidence rates remained static. Declines in MRSA central lineassociated BSI incidence ranged from −51.5% (95% CI, −33.7% to −64.6%; PϽ.001) in nonteaching-affiliated medical-surgical ICUs (0.31 vs 0.15 per 1000 central line days) to −69.2% (95% CI, −57.9% to −77.7%; PϽ.001) in surgical ICUs (0.58 vs 0.18 per 1000 central line days). In all ICU types, MSSA central line-associated BSI incidence declined from 1997 through 2007, with changes in incidence ranging from −60.1% (95% CI, −41.2% to −73.1%; PϽ.001) in surgical ICUs (0.24 vs 0.10 per 1000 central line days) to −77.7% (95% CI, −68.2% to −84.4%; PϽ.001) in medical ICUs (0.40 vs 0.09 per 1000 central line days). Although the overall proportion of S aureus central lineassociated BSIs due to MRSA increased 25.8% (P=.02) in the 1997-2007 period, overall MRSA central line-associated BSI incidence decreased 49.6% (PϽ.001) over this period. Conclusions The incidence of MRSA central line-associated BSI has been decreasing in recent years in most ICU types reporting to the CDC. These trends are not apparent when only percent MRSA is monitored.

Changing Susceptibility of Staphylococcus aureus in a US Pediatric Population

“…This is consistent with several recent reports of declining rates of MRSA in both regional and geographically diverse epidemiologic studies. 3,4,6,23 Before 2005, dramatic increases in rates of community-associated MRSA infection were reported, with most studies revealing oxacillin resistance in 40% to 60% of SSTIs. 16,24,25 The rate of rise of MRSA infections slowed by 2005-2006 and subsequently declined.…”

“…38 In adult and pediatric populations, MRSA bacteremia is by guest on March 24, 2019 www.aappublications.org/news Downloaded from declining, predominantly due to decreasing health care-associated infections. 4,6,39 Improved infection control measures in intensive care units and enhanced surveillance for MRSA are potential reasons for this decline in health care-associated bacteremia, primarily in adult patients. 6,12 Despite this, S aureus remains the number 1 hospitalacquired pathogen and still requires vigilance of current antimicrobial susceptibilities.…”

“…4,6,39 Improved infection control measures in intensive care units and enhanced surveillance for MRSA are potential reasons for this decline in health care-associated bacteremia, primarily in adult patients. 6,12 Despite this, S aureus remains the number 1 hospitalacquired pathogen and still requires vigilance of current antimicrobial susceptibilities. 40 Along with declining rates of MRSA bacteremia, 1 report has also revealed a similar decline in rates of community-associated MSSA bacteremia.…”

“…1 Although MRSA remains a common pathogen, recent studies have revealed a declining incidence of methicillin resistance among S aureus in adult populations in the United States. [3][4][5][6] A similar decline in children has not been well described, with some authors reporting increasing rates of MRSA infections in children. 7 Due to optimal tissue penetration and bactericidal action, antistaphylococcal β-lactam antibiotics are the treatment of choice for susceptible S aureus infections.…”

Network Approach for Prevention of Healthcare-Associated Infections

“…1 DICON provides a successful example of HAI reduction, using validated, risk-adjusted local data to drive prevention activities, and it adds to existing evidence supporting this HAI prevention strategy. 2 " 4 To help ensure an accurate understanding of the current landscape of HAI-reporting infrastructures that can contribute to such reductions, we would like to clarify that the National Healthcare Safety Network (NHSN) can, and in some states does, also function much as DICON does to provide complete, validated, risk-adjusted data for local action, with the distinction that funding for NHSN and, particularly, validation requires public support, whereas DICON is funded directly by the facilities it serves. We disagree with the authors' statement that NHSN data are "obtained from convenience samples (ie, are not complete), are not validated, and are not fed back to individual hospitals in a timely fashion," for the following reasons.…”