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The multicenter, cluster-randomized Strategies to Reduce Transmission of Antimicrobial Resistant Bacteria in Intensive Care Units (STAR*ICU) trial was performed in 18 U.S. adult intensive care units (ICUs). It evaluated the effectiveness of infection control strategies to reduce the transmission of methicillin-resistant Staphylococcus aureus (MRSA) colonization and/or infection. Our study objective was to examine the molecular epidemiology of MRSA and assess the prevalence and risk factors for community acquired (CA)-MRSA genotype nasal carriage at the time of ICU admission.
Selected MRSA isolates were subjected to molecular typing using pulsed-field gel electrophoresis.
Of 5,512 ICU patient admissions in the STAR*ICU trial during the intervention period, 626 (11%) had a nares sample culture result that was positive for MRSA. A total of 210 (34%) of 626 available isolates were selected for molecular typing by weighted random sampling. Of 210 patients, 123 (59%) were male; mean age was 63 years. Molecular typing revealed that 147 isolates (70%) were the USAIOO clone, 26 (12%) were USA300, 12 (6%) were USA500, 8 (4%) were USA800, and 17 (8%) were other MRSA genotypes. In a multivariate analysis, patients who were colonized with a CA-MRSA genotype (USA300, USA400, or USA1000) were less likely to have been hospitalized during the previous 12 months (PR [prevalence ratio], 0.39 [95% confidence interval (CI), 0.21-0.73]) and were less likely to be older (PR, 0.97 [95% CI, 0.95-0.98] per year) compared with patients who were colonized with a healthcare-associated (HA)-MRSA genotype.
CA-MRSA genotypes have emerged as a cause of MRSA nares colonization among patients admitted to adult ICUs in the United States. During the study period (2006), the predominant site of CA-MRSA genotype acquisition appeared to be in the community.
Five hundred adults with an expected length of stay in the ICU greater than 48 hours.
For the intervention group, the protocol required repeated MRSA screening, contact and droplet isolation precautions for patients at risk for MRSA at ICU admission and for MRSA-positive patients, and decontamination with nasal mupirocin and chlorhexidine body wash for MRSA-positive patients. For the standard group, the standard precautions protocol was used, and the results of repeated MRSA screening in the standard group were not communicated to investigators.
Main Outcome Measure.
MRSA acquisition rate in the ICU. An audit was conducted to assess compliance with hygiene and isolation precautions.
In the intent-to-treat analysis (n = 488), the MRSA acquisition rate in the ICU was similar in the standard (13 [5.3%] of 243) and intervention (16 [6.5%] of 245) groups (P =.58). The audit showed that the overall compliance rate was 85.5% in the standard group and 84.1% in the intervention group (P =.63), although compliance was higher when isolation precautions were absent than when they were in place (88.2% vs 79.1%; P<.001). MRSA incidence rates were higher without isolation precautions (7.57‰) than with isolation precautions (2.36‰; P =.01).
Individual allocation to MRSA screening, isolation precautions, and decontamination do not provide individual benefit in reducing MRSA acquisition, compared with standard precautions, although the collective risk was lower during the periods of isolation.
The effect of patient movement between hospitals and long-term care facilities (LTCFs) on methicillin-resistant Staphylococcus aureus (MRSA) prevalence levels is unknown. We investigated these effects to identify scenarios that may lead to increased prevalence in either facility type.
We used a hybrid simulation model to simulate MRSA transmission among hospitals and LTCFs. Transmission within each facility was determined by mathematical model equations. The model predicted the long-term prevalence of each facility and was used to assess the effects of facility size, patient turnover, and decolonization.
Analyses of various healthcare networks suggest that the effect of patients moving from a LTCF to a hospital is negligible unless the patients are consistently admitted to the same unit. In such cases, MRSA prevalence can increase significantly regardless of the endemic level. Hospitals can cause sustained increases in prevalence when transferring patients to LTCFs, where the population size is smaller and patient turnover is less frequent. For 1 particular scenario, the steady-state prevalence of a LTCF increased from 6.9% to 9.4% to 13.8% when the transmission rate of the hospital increased from a low to a high transmission rate.
These results suggest that the relative facility size and the patient discharge rate are 2 key factors that can lead to sustained increases in MRSA prevalence. Consequendy, small facilities or those with low turnover rates are especially susceptible to sustaining increased prevalence levels, and they become more so when receiving patients from larger, high-prevalence facilities. Decolonization is an infection-control strategy that can mitigate these effects.
Central line-associated bloodstream infections (CLABSIs) frequently complicate the use of central venous catheters (CVCs) among pediatric patients with cancer. Our objectives were to describe the microbiology and identify risk factors for hospital-onset CLABSI in this patient population.
Retrospective case-control study.
Oncology and stem cell transplant units of a freestanding, 396-bed quaternary care pediatric hospital.
Case subjects (N = 54) were patients with a diagnosis of malignancy and/or stem cell transplant recipients with CLABSI occurring during admission. Controls (N = 108) were identified using risk set sampling of hospitalizations among patients with a CVC, matched on date of admission.
Multivariate conditional logistic regression was used to identify independent predictors of CLABSI.
The majority of CLABSI isolates were gram-positive bacteria (58%). The most frequently isolated organism was Enterococcus faecium, and 6 of 9 isolates were resistant to vancomycin. In multivariate analyses, independent risk factors for CLABSI included platelet transfusion within the prior week (odds ratio [OR], 10.90 [95% confidence interval (CI), 3.02-39.38]; P<.001) and CVC placement within the previous month (<1 week vs ≥1 month: OR, 11.71 [95% CI, 1.98-69.20]; P = .02; ≥1 week and <1 month vs ≥1 month: OR, 7.37 [95% CI, 1.85-29.36]; P = .004).
Adjunctive measures to prevent CLABSI among pediatric oncology patients may be most beneficial in the month following CVC insertion and in patients requiring frequent platelet transfusions. Vancomycin-resistant enterococci may be an emerging cause of CLABSI in hospitalized pediatric oncology patients and are unlikely to be treated by typical empiric antimicrobial regimens.
Manual surveillance for central line-associated bloodstream infections (CLABSIs) by infection prevention practitioners is time-consuming and often limited to intensive care units (ICUs). An automated surveillance system using existing databases with patient-level variables and microbiology data was investigated.
Patients with a positive blood culture in 4 non-ICU wards at Barnes-Jewish Hospital between July 1, 2005, and December 31, 2006, were evaluated. CLABSI determination for these patients was made via 2 sources; a manual chart review and an automated review from electronically available data. Agreement between these 2 sources was used to develop the best-fit electronic algorithm that used a set of rules to identify a CLABSI. Sensitivity, specificity, predictive values, and Pearson's correlation were calculated for the various rule sets, using manual chart review as the reference standard.
During the study period, 391 positive blood cultures from 331 patients were evaluated. Eighty-five (22%) of these were confirmed to be CLABSI by manual chart review. The best-fit model included presence of a catheter, blood culture positive for known pathogen or blood culture with a common skin contaminant confirmed by a second positive culture and the presence of fever, and no positive cultures with the same organism from another sterile site. The best-performing rule set had an overall sensitivity of 95.2%, specificity of 97.5%, positive predictive value of 90%, and negative predictive value of 99.2% compared with intensive manual surveillance.
Although CLABSIs were slightly overpredicted by electronic surveillance compared with manual chart review, the method offers the possibility of performing acceptably good surveillance in areas where resources do not allow for traditional manual surveillance.
To assess healthcare personnel (HCP) perceptions regarding implementation of sensor-based electronic systems for automated hand hygiene adherence monitoring.
Using a mixed-methods approach, structured focus groups were designed to elicit quantitative and qualitative responses on familiarity, comfort level, and perceived impact of sensor-based hand hygiene adherence monitoring
A university hospital, a Veterans Affairs hospital, and a community hospital in the Midwest.
Focus groups were homogenous by HCP type, with separate groups held for leadership, midlevel management, and frontline personnel at each hospital.
Overall, 89 HCP participated in 10 focus groups. Levels of familiarity and comfort with electronic oversight technology varied by HCP type; when compared with frontline HCP, those in leadership positions were significantly more familiar with (P<.01) and more comfortable with (P<.01) the technology. The most common concerns cited by participants across groups included lack of accuracy in the data produced, such as the inability of the technology to assess the situational context of hand hygiene opportunities, and the potential punitive use of data produced. Across groups, HCP had decreased tolerance for electronic collection of spatial-temporal data, describing such oversight as Big Brother.
While substantial concerns were expressed by all types of HCP, participants' recommendations for effective implementation of electronic oversight technologies for hand hygiene monitoring included addressing accuracy issues before implementation and transparent communication with frontline HCP about the intended use of the data.
Laminar airflow (LAF) systems are widely used, at least in orthopedic surgery. However, there is still controversial discussion about the influence of LAF on surgical site infection (SSI) rates. The size of the LAF ceiling is also often a question of debate. Our objective is to determine the effect of this technique under conditions of actual rather than ideal use.
Cohort study using multivariate analysis with generalized estimating equations method.
Data for hip and knee prosthesis procedures from hospitals participating in the German national nosocomial infection surveillance system (KISS) from July 2004 to June 2009 were used for analysis.
A total of 33,463 elective hip prosthesis procedures due to arthrosis (HIP-A) from 48 hospitals, 7,749 urgent hip prosthesis procedures due to fracture (HIP-F) from 41 hospitals, and 20,554 knee prosthesis (KPRO) procedures from 38 hospitals were included.
The data were analyzed for hospitals with and without LAF in the operating rooms and by the size of the LAF ceiling. The endpoints were severe SSI rates.
The overall severe SSI rate was 0.74 per 100 procedures for HIP-A, 2.39 for HIP-F, and 0.63 for KPRO. For all 3 prosthesis types, neither LAF nor the size of the LAF ceiling was associated with lower infection risk.
The data demonstrate consistency and reproducibility with the results from earlier registry studies. Neither LAF nor ceiling size had an impact on severe SSI rates.
Most professionals in the healthcare environment wear uniforms. For the purpose of this study, we concentrated on nurses' uniforms. In the United Kingdom, many nurses are expected to launder their uniforms at home by using a domestic washing machine that frequently has low-temperature wash cycles. We have investigated whether the use of low-temperature wash cycles results in a microbiologically acceptable product to wear on the wards.
We have assessed the bioburden on uniforms before and after laundry and the effectiveness of low-temperature wash cycles and ironing on removal of methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii. We did not assess the role of tumble drying.
We demonstrate contamination of uniforms by gram-negative bacteria after wash, the removal of MRSA at low-temperature wash cycles in the presence of detergent, and the eradication of gram-negative bacteria after ironing.
Our conclusions are that laundry in a domestic situation at 60°C (140°F) for 10 minutes is sufficient to decontaminate hospital uniforms and reduces the bacterial load by more than 7-log reduction, that items left in the pockets are decontaminated to the same extent, that the addition of either a biological detergent or a nonbiological detergent is beneficial in removing MRSA from experimentally contaminated swatches, and that uniforms become recontaminated with low numbers of principally gram-negative bacteria after laundry but that these are effectively removed by ironing.
Information on the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection transmission in dental healthcare settings was incomplete only few years ago; therefore, MRSA infection control guidelines were necessarily based on data extrapolated from other fields. Recently, publication of specific studies have made it possible to review such risk.
Studies of MRSA infection in dentistry were searched for using EMBASE, MEDLINE, and Google and were allocated into the following sections: (1) direct evidence: documented cases of MRSA transmission in dentistry; (2) indirect evidence: carriage rates among dental healthcare providers (DHCPs) and patients (high carriage rates suggest that transmission is likely); (3) speculative evidence: MRSA occurrence in the dental environment (high environmental contamination probably increases the risk of infection); and (4) speculative evidence: MRSA carriage in human dental plaque and saliva (oral carriers may spread MRSA in the environment during dental therapy, with consequent environmental contamination and probable increased risk of infection).
Our findings were as follows. First, transmission has been ascertained during surgical interventions, particularly in surgical units and among head and neck cancer patients. Second, carriage rates among DHCPs were lower than those among other healthcare workers. Carriage rates among adult patients were low, whereas among pedodontic and special care patients rates were higher than those in the general population. Third, MRSA has been detected in the environment of emergency and surgical units and in dental hospitals. Some individuals in poor general condition were oral MRSA carriers.
The occupational risk of MRSA infection among DHCPs is minimal. Among special patients (eg, special care, hospitalized and cancer patients) the risk of infection is high, whereas among the remaining patients undergoing conventional therapy such risk is probably low.
We describe the clinical, microbiologic, and molecular features of the first series of qacA/B-containing strains of methicillin-resistant Staphylococcus aureus from infected US patients. All qac-carrying strains were clonally diverse, and qacA strains exhibited increased tolerance to chlorhexidine as measured by minimum inhibitory concentrations, minimum bactericidal concentrations, and postexposure colony counts.
We conducted an observational study to identify predictors of hand hygiene (HH) in the emergency department. Compliance with HH was 89.7% over 5,865 opportunities. Observation unit, hallway or high-visibility location, glove use, and worker type predicted worse HH. Hallway location was the strongest predictor (relative risk, 88.9% [95% confidence interval, 85.9%–92.1%]).
Data from a case-control study were used to derive and internally validate a prediction rule for identifying fluoroquinolone resistance in healthcare-acquired gram-negative urinary tract infection. This prediction rule has an excellent sensitivity and specificity (C-statistic, 0.816). External validation is necessary before implementing this rule to optimize empirical antibiotic use in clinical practice.
Little is known about the epidemiology of nosocomial urinary tract-related bloodstream infection. In a case series from an academic medical center, Enterococcus (28.7%) and Candida (19.6%) species were the predominant microorganisms, which suggests a potential shift from gram-negative microorganisms. A case-fatality rate of 32.8% highlights the severity of this condition.
Silicone polymers containing the light-activated antimicrobial agent methylene blue with or without gold nanoparticles were evaluated for their ability to reduce the microbial load on surfaces in a clinical environment. When irradiated with white light, polymers containing nanogold were more effective in this respect than those containing only methylene blue.
We evaluated treatment decisions and antimicrobial use related to 2 testing algorithms for Clostridium difficile infection (CDI). findings suggest that a 2-step testing algorithm using rapid polymerase chain reaction confirmatory testing leads to decreased unnecessary anti-CDI antimicrobial use. In addition, a significant proportion of patients with confirmed CDI were not treated accordingto recommended guidelines.
This study evaluated daily cleaning with germicidal bleach wipes on wards with a high incidence of hospital-acquired Clostridium difficile infection (CDI). The intervention reduced hospital-acquired CDI incidence by 85%, from 24.2 to 3.6 cases per 10,000 patient-days, and prolonged the median time between hospital-acquired CDI cases from 8 to 80 days.