Study highlights limits of mandated MRSA surveillance
A 2007 state law in Illinois mandating active surveillance of methicillin-resistant Staphylococcus aureus (MRSA) in intensive care unit (ICU) patients failed to reduce MRSA prevalence, according to a study yesterday in Clinical Infectious Diseases.
The Illinois law, the first of several passed in the United States, requires hospitals to screen ICU patients for MRSA colonization and place those who test positive for MRSA in contact precautions. While the "search and isolate" strategy has been used to control MRSA during outbreaks, its role in controlling MRSA in non-outbreak settings is more controversial. To evaluate the law's impact, researchers from the US Centers for Disease Control and Prevention and three Chicago hospital systems invited all hospitals in Chicago with more than 10 ICU beds to participate in regional point prevalence surveys for MRSA colonization.
In total, 25 hospitals and 3,909 adult ICU patients participated in the point prevalence surveys over eight survey periods (2008 to 2013). Of the 3,909 patients, 432 (11.1%) were found to be colonized with MRSA, and the prevalence of MRSA colonization prevalence did not change significantly from year 1 to year 5 of the study period; year-over-year relative risk for MRSA colonization was 0.97. In addition, roughly 4 in 10 MRSA-colonized ICU patients were not in contact precautions at the time of cross-sectional surveys.
"Our findings highlight the limits of legislated MRSA active surveillance as a strategy to reduce MRSA colonization burden among ICU patients," the authors write.
Dec 7 Clin Infect Dis study
Controlling ESBL carriage on hospital wards
An analysis of two studies demonstrated a low acquisition rate of extended-spectrum beta-lactamase–producing Enterobacteriaceae (ESBL-E) in 14 Dutch hospitals after contact precautions were used for all ESBL-E carriers.
Writing in Infection Control and Hospital Epidemiology, Dutch investigators detailed their analysis of data from 2011 through 2014 involving perianal cultures. In both studies, staff employed contact precautions for all ESBL-E carriers. The analysis involved patients hospitalized for more than 2 days.
The team determined that the absolute risk acquiring ESBL-E rectal carriage ranged from 2.4% to 2.9%, with an ESBL-E acquisition rate of 2.8 to 3.8 acquisitions per 1,000 patient-days. In addition, 28% of acquisitions were attributable to patient-dependent transmission.
The authors conclude, "The low ESBL-E acquisition rate in this study demonstrates that it is possible to control the nosocomial transmission of ESBL in a low-endemic, non-ICU setting where Escherichia coli is the most prevalent ESBL-E and standard and contact precautions are applied for known ESBL-E carriers."
Dec 7 Infect Control Hosp Epidemiol study
Report details first European outbreak involving certain resistance gene
The first report of a certain drug-resistant strain of beta-lactamase–producing bacteria in Europe points to endoscope contamination, according to a study yesterday in Eurosurveillance.
Researchers examined 29 isolates of OXA-48–like beta-lactamase–producing bacteria from 23 patients collected in France from October 2012 through May 2014, 21 of which remained susceptible to imipenem and meropenem, which complicated their detection. Of those 21 isolates (12 from Escherichia coli and 9 from Klebsiella pneumoniae), all co-produced the cephalosporinase CMY-4 resistance gene, and 60% of them co-produced the extended-spectrum beta-lactamase resistance gene CTX-M-15.
"The results of this analysis led us to do an epidemiologically investigation of this dual outbreak," the authors wrote. "An endoscope was identified as the possible source of the outbreak in that the investigation showed that 17 patients had direct contact with the endoscope, while five (Patients 10, 11, 13, 14 and 16) were considered as secondary cases through patient-to-patient transmission on a clinical ward."
Dec 7 Eurosurveill report