BACKGROUND: Between June 1, 2004, and March 14, 2005, 16 patients in the surgical/medical intensive care unit (ICU) were infected and another 2 were colonized with multidrug-resistant (MDR) Acinetobacter baumannii. We describe the systematic investigation initiated to discover an environmental reservoir and a novel measure taken to terminate the outbreak. METHODS: Cultures were taken from moist areas in the ICU, including sink traps, sink and counter surfaces, drains, and faucets. Strains were characterized using restriction endonuclease analysis. A weekly full drainpipe chase cleansing protocol with sodium hypochlorite (bleach) solution for all 24 ICU and waiting room area sinks connected by common plumbing was initiated in March 2005. RESULTS: Eleven of 16 infected patients (69%) had a clonal MDR strain, 1 patient (6%) was infected with an unrelated strain, and in 4 patients (25%) strains were not available for typing. The reservoir for the A baumannii clone was detected in a sink trap within one of the ICU patient rooms that likely represented contamination of the entire horizontal drainage system. The bleaching protocol initiated in March 2005 successfully decontaminated the reservoir and eliminated the MDR A baumannii infections. CONCLUSION: A systematic search for an environmental reservoir followed by decontamination significantly reduced (P <.01) the incidence of MDR A baumannii infection.

Our 3 hospital system began active surveillance for MRSA nasal colonization on all admissions starting August 1, 2005 with decolonization of positive patients. A question not previously addressed is whether reduction of MRSA disease would lower total S. aureus clinical isolates recovered by the microbiology laboratory that are reported to healthcare providers. The decrease in number of MRSA and total S. aureus clinical isolates for each year after August 2005 was highly statistically significant compared to each of the prior 3 years (p<0.0001).

Objective. We evaluated the usefulness of topical decolonization therapy for reducing the risk of methicillin-resistant Staphylococcus aureus (MRSA) infection among MRSA-colonized inpatients. Design. Retrospective cohort study. Setting and intervention. Three hospitals with universal surveillance for MRSA; at their physician's discretion, colonized patients could be treated with a 5-day course of nasal mupirocin calcium 2%, twice daily, plus chlorhexidine gluconate 4% every second day. Patients and methods. MRSA carriers were later retested for colonization (407 subjects; study 1) or followed up for development of MRSA infection (933 subjects; study 2). Multivariable methods were used to determine the impact of decolonization therapy on the risks of sustained colonization (in study 1) and MRSA infection (in study 2). Results. Independent risk factors for sustained colonization included residence in a long-term care facility (odds ratio [OR], 1.8 [95% confidence interval {CI}, 1.1-3.2]) and a pressure ulcer (OR, 2.3 [95% CI, 1.2-4.4]). Mupirocin at any dose decreased this risk, particularly during the 30-60-day period after therapy; mupirocin resistance increased this risk (OR, 4.1 [95% CI, 1.6-10.7]). Over a median follow-up duration of 269 days, 69 (7.4%) of 933 patients developed infection. Independent risk factors for infection were length of stay (hazard ratio [HR], 1.2 per 5 additional days [95% CI, 1.0-1.4]), chronic lung disease (HR, 1.7 [95% CI, 1.0-2.8]), and receipt of non-MRSA-active systemic antimicrobial agents (HR, 1.8 [95% CI, 1.1-3.1]). Receipt of mupirocin did not affect the risk of infection, although there was a trend toward delayed infection among patients receiving mupirocin (median time to infection, 50 vs 15.5 days;[Formula: see text]). Conclusions. Mupirocin-based decolonization therapy temporarily reduced the risk of continued colonization but did not decrease the risk of subsequent infection.

BACKGROUND: Complex regional pain syndrome (CRPS) is a common problem presenting to orthopedic surgeons or pain therapists, most frequently encountered after trauma or surgery to a limb. Because of a lack of a simple objective diagnostic test, diagnosis is reliant on clinical assessment. Prospective studies have repeatedly demonstrated a higher incidence than retrospective studies, an observation that has been challenged owing to the lack of uniformity of diagnostic criteria across specialties and workers researching the condition. METHODS: A series of 262 adult patients presenting to the Bristol Royal Infirmary with a closed unilateral distal radial fracture were assessed at a mean of 9.47 weeks after their injury by a single clinician (J.A.L.). Each assessment made allowed comparison of the modified International Association for the Study of Pain (Bruehl) criteria for the presence of CRPS with the criteria described by Atkins. FINDINGS: The incidence of CRPS was similar using either criteria (Bruehl 20.61% vs. Atkins 22.52%). Using the Bruehl criteria as a gold standard, there was strong diagnostic agreement (kappa=0.79, sensitivity=0.87, specificity=0.94). Disagreements between the 2 criteria methods were found in 19 patients. The majority of these discordances were due to differences in pain and sensory abnormality assessment. INTERPRETATION: These findings show that the Bruehl and Atkins criteria are basically concordant. The differences reflect only minor variations in the assessment of pain. Agreement between researchers in the orthopedic and pain therapy communities will allow improved understanding of CRPS.

BACKGROUND: The effect of large-scale expanded surveillance for methicillin-resistant Staphylococcus aureus (MRSA) on health care-associated MRSA disease is not known. OBJECTIVE: To examine the effect of 2 expanded surveillance interventions on MRSA disease. DESIGN: Observational study comparing rates of MRSA clinical disease during and after hospital admission in 3 consecutive periods: baseline (12 months), MRSA surveillance for all admissions to the intensive care unit (ICU)(12 months), and universal MRSA surveillance for all hospital admissions (21 months). SETTING: A 3-hospital, 850-bed organization with approximately 40,000 annual admissions. INTERVENTION: Polymerase chain reaction-based nasal surveillance for MRSA followed by topical decolonization therapy and contact isolation of patients who tested positive for MRSA. MEASUREMENTS: Poisson and segmented regression models were used to compare prevalence density of hospital-associated clinical MRSA disease (bloodstream, respiratory, urinary tract, and surgical site) in each period. Rates of bloodstream disease with methicillin-susceptible S. aureus were used as a control. RESULTS: The prevalence density of aggregate hospital-associated MRSA disease (all body sites) per 10,000 patient-days at baseline, during ICU surveillance, and during universal surveillance was 8.9 (95% CI, 7.6 to 10.4), 7.4 (CI, 6.1 to 9.0; P = 0.15 compared with baseline), and 3.9 (CI, 3.2 to 4.7; P < 0.001 compared with baseline and ICU surveillance), respectively. During universal surveillance, the prevalence density of MRSA infection at each body site had a statistically significant decrease compared with baseline. The methicillin-susceptible S. aureus bacteremia rate did not statistically significantly change during the 3 periods. In a segmented regression model, the aggregate hospital-associated MRSA disease prevalence density changed by -36.2%(CI,-65.4% to 9.8%; P = 0.17) from baseline to ICU surveillance and by -69.6%(CI,-89.2% to -19.6%]; P = 0.03) from baseline to universal surveillance. During universal surveillance, the MRSA disease rate decreased during hospitalization and in the 30 days after discharge; no further reduction occurred thereafter. Surveillance with clinical cultures would have identified 17.8% of actual MRSA patient-days, and ICU-based surveillance with polymerase chain reaction would have identified 33.3%. LIMITATION: The findings rely on observational data. CONCLUSION: The introduction of universal admission surveillance for MRSA was associated with a large reduction in MRSA disease during admission and 30 days after discharge.

Background. Nasal colonization with methicillin-resistant Staphylococcus aureus (MRSA) is believed to precede disease. It is therefore reasonable to expect that testing for nasal MRSA colonization could provide guidance in choice of empiric therapy for infections. Methods. Retrospective review of 5,779 nasal MRSA tests obtained within 24 hours before or after a clinical culture growing any organism. Results. A positive nasal MRSA test strongly predicted MRSA involvement in a clinical site (relative risk 12.9, 95% CI, 10.4, 16.1). Nasal MRSA colonization also strongly predicted antimicrobial resistance in other organisms. A negative nasal test was less useful; only 217 (67.2%, 95% CI 61.8, 72.3) of 323 patients with clinical cultures involving MRSA had detectable concomitant nasal MRSA colonization. Patients with clindamycin-susceptible MRSA were less likely (59%) to have nasal colonization than those with clindamycin-resistant MRSA (71%, P = 0.042). Conclusions. Patients nasally colonized with MRSA were substantially more likely to have antibiotic resistant flora in clinical isolates and this should be considered when initiating therapy. However, nearly a third of MRSA-infected patients were not nasally colonized, suggesting that nasal colonization need not precede disease and that a negative test for nasal colonization would not rule out MRSA disease in settings of moderate or high prevalence.

BACKGROUND: Clostridium difficile-associated diarrhea (CDAD) is the major cause of health care-associated infectious diarrhea. Current laboratory testing lacks a single assay that is sensitive, specific, and rapid. The purpose of this work was to design and validate a sensitive and specific real-time polymerase chain reaction (PCR) diagnostic test for CDAD. METHODS: This observational validation study of a new real-time PCR assay occurred from July 2004 through April 2006 and involved the testing of 1368 stool samples. As the final validation portion of the investigation, 350 inpatients were prospectively interviewed for clinical findings for 365 episodes of diarrheal illness. Test results and clinical criteria were used to assess the performance of 4 assays. RESULTS: Using clinical criteria requiring at least 3 loose stools in 1 day as part of the reference standard for a positive test result supporting CDAD, the sensitivity, specificity, and positive and negative predictive values were 73.3%, 97.6%, 73.3%, and 97.6%, respectively, for enzyme immunoassay; 93.3%, 97.4%, 75.7%, and 99.4%, respectively, for real-time PCR; 76.7%, 97.1%, 69.7%, and 97.9%, respectively, for cell culture cytotoxin assay; and 100.0%, 95.9%, 68.2%, and 100.0%, respectively, for anaerobic culture (for toxigenic C. difficile strains). The real-time PCR and anaerobic culture assays were significantly more sensitive than the enzyme immunoassay (P<.01 to P<.05). CONCLUSIONS: With an assay turnaround time of <4 h, real-time PCR is a more sensitive and equally rapid test, compared with enzyme immunoassay, and is a feasible laboratory option to replace enzyme immunoassay for toxigenic C. difficile detection in clinical practice, as well as for use during the development of new therapeutic agents.

We evaluated use of the BD GeneOhm(TM) MRSA (BD Diagnostics, San Diego, CA) real-time PCR assay for the detection of methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization. The initial evaluation consisted of 403 paired nasal swabs and was done using the kit provided specimen preparation and an in-house lysis method that was specifically developed to accommodate large volume testing using a minimal amount of personnel time. One swab was placed into an achromopeptidase (ACP) lysis solution and the other was used for culture, then prepared according to the kit protocol. PCR was performed on both lysates with results compared to culture. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the PCR assay was 98%, 96%, 77%, and 99.7% with the kit lysate and 98%, 95%, 75% and 99.7% with the ACP lysate (p = NS). The second evaluation was done after implementation of all-admission surveillance using PCR with ACP lysis and a sampling of 1107 PCR negative samples and 215 PCR positive samples that were confirmed by culture. The results of this sampling showed a NPV of 99.9% and a PPV of 73.5%(prevalence = 6%), which were consistent with our initial findings. The BD GeneOhm(TM) MRSA assay is an accurate and rapid way to detect MRSA nasal colonization. When dealing with large specimen numbers, the ACP lysis method offers easier processing without negatively affecting the PCR assay sensitivity or specificity.