Methicillin-ResistantStaphylococcus aureusControl: We Didn't Start the Fire, but It's Time to Put It Out

Abstract

The prevalence of healthcare-associated infections (HAIs) caused by multidrug-resistant organisms has significantly increased over the past decade, according to the measurements of the Centers for Disease Control and Prevention, and will likely continue to climb. 1 ' 2 Currently, more than 70% of HAIs are caused by bacteria that are resistant to at least 1 of the drugs most commonly used to treat these infections. 3 These HAIs have been associated with increased cost and mortality, compared with infections due to antibiotic-susceptible strains of the same bacterial species. 4,5 Nevertheless, despite decades of studies confirming increased rates of adverse events related to these organisms and ongoing evidence of increased prevalence of multidrug-resistant organisms, 2 as well as the emergence of new antimicrobial-resistant organisms, 6 few coordinated effective efforts exist across the United States and most parts of the world to prevent MRSA transmission and reduce the number of MRSA HAIs. 7 Despite evidence of efficacy for control of multidrug-resistant organisms with active surveillance cultures and barrier precautions 8 " 10 and despite documented failure to control MRSA in studies lacking methods to fully identify the MRSA reservoir, 8 most healthcare systems have not elected to implement methods to identify and contain MRSA, and so MRSA continues to spread and to colonize and infect patients. Several studies in this issue of Infection Control and HospitalEpidemiology describe efforts to control methicillin-resistant S. aureus (MRSA). I comment here on 3 of them. 11 " 13 Interestingly, the investigators in these 3 studies believe that colonized patients represented a significant portion of the MRSA reservoir and elected to implement a program of active surveillance cultures to better identify MRSA-colonized patients. In two of the studies, that of Salgado and Farr 11 and that of Eveillard et al., 12 barrier precautions were implemented for all patients identified as being MRSA colonized, as recommended by the recent Society for Healthcare Epidemiology of America (SHEA) guideline. 8 The third study, by Sandri et al., 13 discusses the utility of MRSA decolonization of the nares by administration of topical mupirocin therapy and chlorhexidine baths to all patients identified as having MRSA colonization of the nares.The study by Salgado and Farr" reports the proportion of patients identified by active surveillance culture on admission as being MRSA colonized who later had an MRSA-positive clinical microbiology culture, the number and type of clinical microbiology cultures done, and the number and type of MRSA-positive clinical microbiology cultures. Their study demonstrates that only 15% of all patients identified as being colonized with MRSA on admission would have been so identified subsequently via clinical microbiology culture. When data for patients in the intensive care unit (ICU) and in other units (non-ICU patients) were analyzed separately, the investigators found that 21.4% of ICU patients had a subse...

Spectra MRSA, a New Chromogenic Agar Medium To Screen for Methicillin-ResistantStaphylococcus aureus

“…aureus colonization and the most frequently screened and recommended site for specimen collection due to the satisfactory sensitivities of tests with that type of specimen and the ease with the specimen may be obtained (15,18,20), other recent studies have shown that sampling of other body sites (the oropharynx, perianal region, and groin) may enhance the sensitivity of screening for MRSA and predict the likelihood of S. aureus infection (3,7,11,14,22). Most importantly, it is agreed that the culture of specimens from more body sites would yield higher rates of recovery, but the increased resources required for the screening of specimens from multiple sites outweigh the incremental increase in yield that would be attained (5).…”

“…Recent reports by Salgado and Farr (17) and Lucet et al (13) have shown that the organisms in positive cultures of clinical specimens routinely submitted from patients represent only a small fraction of the reservoir of antibiotic-resistant pathogens, and the largest source for nosocomial spread was attributed to asymptomatic, colonized patients who went unrecognized and unisolated in the absence of ASCs. Additionally, consensus suggests that a restricted formulary alone is unlikely to prevent the emergence and persistence of MRSA and that the use of contact precautions is important to prevent the spread of MRSA from colonized patients (5).While the anterior nares are the most common site of S.aureus colonization and the most frequently screened and recommended site for specimen collection due to the satisfactory sensitivities of tests with that type of specimen and the ease with the specimen may be obtained (15,18,20), other recent studies have shown that sampling of other body sites (the oropharynx, perianal region, and groin) may enhance the sensitivity of screening for MRSA and predict the likelihood of S. aureus infection (3,7,11,14,22). Most importantly, it is agreed that the culture of specimens from more body sites would yield higher rates of recovery, but the increased resources required for the screening of specimens from multiple sites outweigh the incremental increase in yield that would be attained (5).…”

Is an increase of MRSA in Oslo, Norway, associated with changed infection control policy?

“…36 When testing only clinical isolates, up to 85% of MRSA cases are undetected. 30,33,37 At least 25e50% of MRSA cases are undetected when screening only the nose. 30,31,34,37 The combination of throat and perineum may have the highest detection rate (98.3%).…”

“…30,33,37 At least 25e50% of MRSA cases are undetected when screening only the nose. 30,31,34,37 The combination of throat and perineum may have the highest detection rate (98.3%). 24 Outbreaks may be extended by lack of testing of the throat.…”

The role of healthcare personnel in the maintenance and spread of methicillin-resistant Staphylococcus aureus

“…The movement for MRSA control is timely and necessary [188,[223][224][225][226][227][228]: at all levels, we need more Mutos and Farrs and Dancers and Simmons and Casewells and Vos and Verbrughs and Farringtons and their like-minded. Institutions with high endemicity can achieve control [227].…”