Controlling methicillin-resistant Staphylococcus aureus : Quantifying the effects of interventions and rapid diagnostic testing

Abstract

Control of nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) has been unsuccessful in most countries. Yet, some countries have maintained low endemic levels by implementing nationwide MRSA-specific infection control measures, such as ''search & destroy'' (S&D). These strategies, however, are not based on well designed studies, and their use in countries with high levels of endemicity is controversial. We present a stochastic three-hospital model and an analytical one-hospital model to quantify the effectiveness of different infection control measures and to predict the effects of rapid diagnostic testing (RDT) on isolation needs. Isolation of MRSA carriers identified by clinical cultures is insufficient to control MRSA. However, combined with proactive search (of high-risk patients on admission and͞or contacts of index patients), it will maintain prevalence levels <1%. Concerted implementation of S&D in countries with high nosocomial endemicity reduces nosocomial prevalence to <1% within 6 years. Stepwise implementation of control measures can reduce isolation capacities needed. RDT can reduce isolation needs by >90% in low-endemic settings and by 20% in high-endemic settings. Surveillance of colonization and improved hand hygiene can markedly increase control efficacy. These findings strongly suggest that: (i) causality exists between S&D and low MRSA prevalence; (ii) isolating MRSA carriers identified by clinical cultures as a single measure is insufficient for control; (iii) a combined approach of isolation and screening confers efficacy; and (iv) MRSA-prevalence levels can be reduced to <1% in high-endemic settings by S&D or a stepwise approach to interventions. RDT can markedly enhance feasibility.infection control ͉ mathematical model ͉ search & destroy ͉ antibiotic resistance

Empfehlungen zur Prävention und Kontrolle von Methicillin-resistenten Staphylococcus aureus-Stämmen (MRSA) in medizinischen und pflegerischen Einrichtungen

“…In jeder dritten Probe der 126 untersuchten Masthähnchen konnten LA-MRSA ST398 in deutlicher Quantität (100-1000 KbE pro ml Auftauwasser) nachgewiesen werden [237]; eine hohe Nachweisrate ist auch für Putenfleisch bekannt [238]. Obwohl LA-MRSA bei allen lebensmittelliefernden Tieren und deren Fleischprodukten nachgewiesen wur- [272,273]. Trotz der umfangreichen Evidenz, die für die Implementation von MRSA-Screenings spricht, haben einige Studien keine Effektivität dieser Maßnahme dokumentieren können [274][275][276][277][278] In einer aktuellen Studie aus Melbourne [295] (ITS, 4.194 Aufnahmen, MRSA-Prävalenz 5,7 %) stieg das Risiko einer MRSA-Infektion mit der Zahl der kolonisierten Abstrichorte (HR, 3,4 bei mehr als einem positiven Abstrichort; 95 %-CI 1,2-9,9).…”

Emergence of SCCmec Type IV as the Most Common Type of Methicillin-Resistant Staphylococcus aureus in a University Hospital

“…To summarize, MRSA harboring genetic markers of CA-MRSA have increased over the past years at our hospital and appear to replace traditional hospital MRSA strains. Bootsma et al [26] already predicted in their model that CA-MRSA strains would replace, not add to, traditional HA-MRSA strains. Data from our study and those by Popovich support this model [22].…”

A comparative in vitro photoinactivation study of clinical isolates of multidrug-resistant pathogens

“…Methicillin-resistant Staphylococcus aureus (MRSA) and extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are two of the commonest MDR pathogens at present causing worldwide concern. 1,2 It is reported that 69.8% of all S. aureus isolates are resistant to oxacillin, 3 while ESBL-producing E. coli accounts for 11% of all E. coli isolates in Hong Kong. 4 Antimicrobial photodynamic inactivation (PDI) is perhaps an alternative strategy to combat these MDR pathogens.…”