Targeted surveillance of methicillin-resistant Staphylococcus aureus and its potential use to guide empiric antibiotic therapy.

The present study aimed to determine the frequency of methicillin-resistant Staphylococcus aureus (MRSA)-positive clinical culture among hospitalized adults in different risk categories of a targeted MRSA active surveillance screening program and to assess the utility of screening in guiding empiric antibiotic therapy. We completed a prospective cohort study in which all adults admitted to non-intensive-care-unit locations who had no history of MRSA colonization or infection received targeted screening for MRSA colonization upon hospital admission. Anterior nares swab specimens were obtained from all high-risk patients, defined as those who self-reported admission to a health care facility within the previous 12 months or who had an active skin infection on admission. Data were analyzed for the subcohort of patients in whom an infection was suspected, determined by (i) receipt of antibiotics within 48 h of admission and/or (ii) the result of culture of a sample for clinical analysis (clinical culture) obtained within 48 h of admission. Overall, 29,978 patients were screened and 12,080 patients had suspected infections. A total of 46.4% were deemed to be at high risk on the basis of the definition presented above, and 11.1% of these were MRSA screening positive (colonized). Among the screening-positive patients, 23.8% had a sample positive for MRSA by clinical culture. Only 2.4% of patients deemed to be at high risk but found to be screening negative had a sample positive for MRSA by clinical culture, and 1.6% of patients deemed to be at low risk had a sample positive for MRSA by clinical culture. The risk of MRSA infection was far higher in those who were deemed to be at high risk and who were surveillance culture positive. Targeted MRSA active surveillance may be beneficial in guiding empiric anti-MRSA therapy.

Methicillin-resistant Staphylococcus aureus infection and colonization among hospitalized prisoners.

We assessed methicillin-resistant Staphylococcus aureus (MRSA) infection and colonization in hospitalized prisoners. Of 434 admission surveillance cultures, 58 (13%) were positive for MRSA. The sensitivity of admission surveillance cultures of samples from the anterior nares was 72% and increased to 84% when the calculation included cultures of wound samples. Hospitalized prisoners are at high risk for MRSA infection and colonization, and surveillance should include cultures of nares and wound samples.

Value of performing active surveillance cultures on intensive care unit discharge for detection of methicillin-resistant Staphylococcus aureus.

OBJECTIVE: To quantify the value of performing active surveillance cultures for detection of methicillin-resistant Staphylococcus aureus (MRSA) on intensive care unit (ICU) discharge. DESIGN: Prospective cohort study. SETTING: Medical ICU (MICU) and surgical ICU (SICU) of a tertiary care hospital. PARTICIPANTS: We analyzed data on adult patients who were admitted to the MICU or SICU between January 17, 2001, and December 31, 2004. All participants had a length of ICU stay of at least 48 hours and had surveillance cultures of anterior nares specimens performed on ICU admission and discharge. Patients who had MRSA-positive clinical cultures in the ICU were excluded. RESULTS: Of 2,918 eligible patients, 178 (6%) were colonized with MRSA on ICU admission, and 65 (2%) acquired MRSA in the ICU and were identified by results of discharge surveillance cultures. Patients with MRSA colonization confirmed by results of discharge cultures spent 853 days in non-ICU wards after ICU discharge, which represented 27% of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU. CONCLUSIONS: Surveillance cultures of nares specimens collected at ICU discharge identified a large percentage of MRSA-colonized patients who would not have been identified on the basis of results of clinical cultures or admission surveillance cultures alone. Furthermore, these patients were responsible for a large percentage of the total number of MRSA colonization-days during hospitalization in non-ICU wards for patients discharged from the ICU.

Impact of a computerized clinical decision support system on reducing inappropriate antimicrobial use: a randomized controlled trial.

OBJECTIVE: Many hospitals utilize antimicrobial management teams (AMTs) to improve patient care. However, most function with minimal computer support. We evaluated the effectiveness and cost-effectiveness of a computerized clinical decision support system for the management of antimicrobial utilization. DESIGN: A randomized controlled trial in adult inpatients between May 10 and August 3, 2004. Antimicrobial utilization was managed by an existing AMT using the system in the intervention arm and without the system in the control arm. The system was developed to alert the AMT of potentially inadequate antimicrobial therapy. MEASUREMENTS: Outcomes assessed were hospital antimicrobial expenditures, mortality, length of hospitalization, and time spent managing antimicrobial utilization. RESULTS: The AMT intervened on 359 (16%) of 2,237 patients in the intervention arm and 180 (8%) of 2,270 in the control arm, while spending approximately one hour less each day on the intervention arm. Hospital antimicrobial expenditures were $285,812 in the intervention arm and $370,006 in the control arm, for a savings of $84,194 (23%), or $37.64 per patient. No significant difference was observed in mortality (3.26% vs. 2.95%, p = 0.55) or length of hospitalization (3.84 vs. 3.99 days, p = 0.38). CONCLUSION: Use of the system facilitated the management of antimicrobial utilization by allowing the AMT to intervene on more patients receiving inadequate antimicrobial therapy and to achieve substantial time and cost savings for the hospital. This is the first study that demonstrates in a patient-randomized controlled trial that computerized clinical decision support systems can improve existing antimicrobial management programs.

Preliminary assessment of an automated surveillance system for infection control.

BACKGROUND AND OBJECTIVE: Rapid identification and investigation of potential outbreaks is key to limiting transmission in the healthcare setting. Manual review of laboratory results remains a cumbersome, time-consuming task for infection control practitioners (ICPs). Computer-automated techniques have shown promise for improving the efficiency and accuracy of surveillance. We examined the use of automated control charts, provided by an automated surveillance system, for detection of potential outbreaks. SETTING: A 656-bed academic medical center. METHODS: We retrospectively reviewed 13 months (November 2001 through November 2002) of laboratory-patient data, comparing an automated surveillance application with standard infection control practices. We evaluated positive predictive value, sensitivity, and time required to investigate the alerts. An ICP created 75 control charts. A standardized case investigation form was developed to evaluate each alert for the likelihood of nosocomial transmission based on temporal and spatial overlap and culture results. RESULTS: The 75 control charts were created in 75 minutes and 18 alerts fired above the 3-sigma level. These were independently reviewed by an ICP and associate hospital epidemiologist. The review process required an average of 20 minutes per alert and the kappa score between the reviewers was 0.82. Eleven of the 18 alerts were determined to be potential outbreaks, yielding a positive predictive value of 0.61. Routine surveillance identified 5 of these 11 alerts during this time period. CONCLUSION: Automated surveillance with user-definable control charts for cluster identification was more sensitive than routine methods and is capable of operating with high specificity and positive predictive value in a time-efficient manner.

Aggressive control measures for resistant Acinetobacter baumannii and the impact on acquisition of methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococcus in a medical intensive care unit.

The medical ICU implemented aggressive control measures following an outbreak of multidrug-resistant, clonal Acinetobacter baumannii. Multivariable regression analyses comparing acquisition (6 months preceding to 6 months during or following the outbreak) revealed decreased VRE and MRSA acquisition. Aggressive control measures can reduce VRE, and perhaps MRSA, transmission.

Effectiveness of an antimicrobial polymer to decrease contamination of environmental surfaces in the clinical setting.

We performed a real-world, controlled intervention to investigate use of an antimicrobial surface polymer, MSDS Poly, on environmental contamination. Pathogenic bacteria were identified in 18 (90%) of 20 observations in treated rooms and 19 (83%) of 23 observations in untreated rooms (P = .67). MSDS Poly had no significant effect on environmental contamination.

Antimicrobial stewardship at a large tertiary care academic medical center: cost analysis before, during, and after a 7-year program.

BACKGROUND: An antimicrobial stewardship program was fully implemented at the University of Maryland Medical Center in July 2001 (beginning of fiscal year [FY] 2002). Essential to the program was an antimicrobial monitoring team (AMT) consisting of an infectious diseases-trained clinical pharmacist and a part-time infectious diseases physician that provided real-time monitoring of antimicrobial orders and active intervention and education when necessary. The program continued for 7 years and was terminated in order to use the resources to increase infectious diseases consults throughout the medical center as an alternative mode of stewardship. DESIGN: A descriptive cost analysis before, during, and after the program. PATIENTS/SETTING: A large tertiary care teaching medical center. METHODS: Monitoring the utilization (dispensing) costs of the antimicrobial agents quarterly for each FY. RESULTS: The utilization costs decreased from $44,181 per 1,000 patient-days at baseline prior to the full implementation of the program (FY 2001) to $23,933 (a 45.8% decrease) by the end of the program (FY 2008). There was a reduction of approximately $3 million within the first 3 years, much of which was the result of a decrease in the use of antifungal agents in the cancer center. After the program was discontinued at the end of FY 2008, antimicrobial costs increased from $23,933 to $31,653 per 1,000 patient-days, a 32.3% increase within 2 years that is equivalent to a $2 million increase for the medical center, mostly in the antibacterial category. CONCLUSIONS: The antimicrobial stewardship program, using an antimicrobial monitoring team, was extremely cost effective over this 7-year period.

Prevalence of methicillin-resistant Staphylococcus aureus and Acinetobacter baumannii in a long-term acute care facility.

BACKGROUND: Patients in long-term acute care (LTAC) facilities often have many known risk factors for acquisition of antibiotic-resistant bacteria. However, the prevalence of resistance in these facilities has not been well described. METHODS: We performed a single-day, point-prevalence study of a 180-bed, university-affiliated LTAC facility in Baltimore to assess the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii in the anterior nares, perirectal area, sputum, and wounds. RESULTS: Among the 147 patients evaluated, we found a high prevalence of colonization by both MRSA (28%) and A baumannii (30%). Of the A baumannii isolates, 90% were susceptible to imipenem and 92% were susceptible to ampicillin-sulbactam. No isolates were resistant to both imipenem and ampicillin-sulbactam. CONCLUSION: The high prevalence of resistance found in this study supports the need for increased surveillance of patients in the LTAC environment. The fact that these patients are often frequently transferred to tertiary care facilities also supports the need for coordination and collaboration among facilities within the same health care system and the broader geographic area.

Video-based training increases sterile-technique compliance during central venous catheter insertion.

OBJECTIVE: To evaluate the effect of an online training course containing video clips of central venous catheter insertions on compliance with sterile practice. DESIGN: Prospective randomized controlled study. SETTING: Admitting area of a university-based high-volume trauma center. SUBJECTS: Surgical and emergency medicine residents rotating through the trauma services. INTERVENTIONS: An online training course on recommended sterile practices during central venous catheter insertion was developed. The course contained short video clips from actual patient care demonstrating common noncompliant behaviors and breaks regarding recommended sterile practices. A 4-month study with a counterbalanced design compared residents trained by the video-based online training course (video group) with those trained with a paper version of the course (paper group). Residents who inserted central venous catheters but received neither the paper nor video training were used as a control group. Consecutive central venous catheter insertions from 12 noon to 12 midnight except Sundays were video recorded. MEASUREMENTS AND MAIN RESULTS: Sterile-practice compliance was judged through video review by two surgeons blinded to the training status of the residents. Fifty residents inserted 73 elective central venous catheters (19, 31, and 23 by the video, paper, and control group operators, respectively) into 68 patients. Overall compliance with proper operator preparation, skin preparation, and draping was 49% (36 of 73 procedures). The training had no effect on selection of site and skin preparation agent. The video group was significantly more likely than the other two groups to fully comply with sterile practices (74% vs. 33%; odds ratio, 6.1; 95% confidence interval, 2.0-22.0). Even after we controlled for the number of years in residency training, specialty, number of central venous catheters inserted, and central venous catheter site chosen, the video group was more likely to comply with recommended sterile practices (p = .003). CONCLUSIONS: An online training course, with short video clips of actual patient care demonstrating noncompliant behaviors, improved sterile-practice compliance for central venous catheter insertion. Paper handouts with equivalent content did not improve compliance.

Risk factors for colonization with extended-spectrum beta-lactamase-producing bacteria and intensive care unit admission.

Extended-spectrum beta-lactamase (ESBL)-producing bacteria are emerging pathogens. To analyze risk factors for colonization with ESBL-producing bacteria at intensive care unit (ICU) admission, we conducted a prospective study of a 3.5-year cohort of patients admitted to medical and surgical ICUs at the University of Maryland Medical Center. Over the study period, admission cultures were obtained from 5,209 patients. Of these, 117 were colonized with ESBL-producing Escherichia coli and Klebsiella spp., and 29 (25%) had a subsequent ESBL-positive clinical culture. Multivariable analysis showed the following to be statistically associated with ESBL colonization at admission: piperacillin-tazobactam (odds ratio [OR] 2.05, 95% confidence interval [CI] 1.36-3.10), vancomycin (OR 2.11, 95% CI 1.34-3.31), age > 60 years (OR 1.79, 95% CI 1.24-2.60), and chronic disease score (OR 1.15; 95% CI 1.04-1.27). Coexisting conditions and previous antimicrobial drug exposure are thus predictive of colonization, and a large percentage of these patients have subsequent positive clinical cultures for ESBL-producing bacteria.

Multidrug-resistant Acinetobacter infection mortality rate and length of hospitalization.

Acinetobacter infections have increased and gained attention because of the organism's prolonged environmental survival and propensity to develop antimicrobial drug resistance. The effect of multidrug-resistant (MDR) Acinetobacter infection on clinical outcomes has not been reported. A retrospective, matched cohort investigation was performed at 2 Baltimore hospitals to examine outcomes of patients with MDR Acinetobacter infection compared with patients with susceptible Acinetobacter infections and patients without Acinetobacter infections. Multivariable analysis controlling for severity of illness and underlying disease identified an independent association between patients with MDR Acinetobacter infection (n = 96) and increased hospital and intensive care unit length of stay compared with 91 patients with susceptible Acinetobacter infection (odds ratio [OR] 2.5, 95% confidence interval [CI] 1.2-5.2 and OR 2.1, 95% CI 1.0-4.3] respectively) and 89 uninfected patients (OR 2.5, 95% CI 1.2-5.4 and OR 4.2, 95% CI 1.5-11.6] respectively). Increased hospitalization associated with MDR Acinetobacter infection emphasizes the need for infection control strategies to prevent cross-transmission in healthcare settings.

Methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci co-colonization.

We assessed the prevalence, risk factors, and clinical outcomes of patients co-colonized with vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) upon admission to the medical and surgical intensive care units (ICUs) of a tertiary-care facility between January 1, 2002, and December 31, 2003. Co-colonization was defined as a VRE-positive perirectal surveillance culture with an MRSA-positive anterior nares surveillance culture collected concurrently. Among 2,440 patients, 65 (2.7%) were co-colonized. Independent risk factors included age (odds ratio [OR] 1.03, 95% confidence interval [CI] 1.01-1.05), admission to the medical ICU (OR 4.38, 95% CI 2.46-7.81), male sex (OR 1.93, 95% CI 1.14-3.30), and receiving antimicrobial drugs on a previous admission within 1 year (OR 3.06, 95% CI 1.85-5.07). None of the co-colonized patients would have been identified with clinical cultures alone. We report a high prevalence of VRE/MRSA co-colonization upon admission to ICUs at a tertiary-care hospital.

Worldwide assessment of linezolid's clinical safety and tolerability: comparator-controlled phase III studies.

Linezolid, an oxazolidinone antibiotic, has 100% oral bioavailability and favorable activities against gram-positive pathogens including multidrug-resistant staphylococci, enterococci, and pneumococci. Safety assessments were conducted for 2,046 linezolid-treated patients and 2,001 comparator drug-treated patients from seven controlled clinical trials comparing the activities of linezolid and comparator drugs against nosocomial and community-acquired pneumonia, skin and skin structure infections, and methicillin-resistant staphylococcal infections. Drug-related adverse events were primarily transient. The most frequent (> or = 2%) adverse events caused by linezolid and the comparator drugs were diarrhea (4.3 and 3.2%, respectively; P = 0.074), nausea (3.4 and 2.3%, respectively; P = 0.036), and headache (2.2 and 1.3%, respectively; P = 0.047). Treatment discontinuations due to drug-related events (2.4 and 1.9%, respectively), serious adverse events (11.4 and 10.6%, respectively), and deaths (4.8 and 4.9%, respectively) were similar. No clinically significant drug-related hematologic events were reported, and laboratory safety data were comparable. In the first 6 months of postmarketing surveillance, hematologic abnormalities were reported in 0.1% of linezolid-treated patients, but no irreversible blood dyscrasias were documented. The risk for transient, reversible hematologic effects from treatment with linezolid should be considered together with the clinical benefits associated with its use.