To estimate the excess length of stay in an intensive care unit (ICU) due to a central line-associated bloodstream infection (CLABSI), using a multistate model that accounts for the timing of infection.

A cohort of 3,560 patients followed up for 36,806 days in ICUs.

Eleven ICUs in 3 Latin American countries: Argentina, Brazil, and Mexico.

All patients admitted to the ICU during a defined time period with a central line in place for more than 24 hours.

The average excess length of stay due to a CLABSI increased in 10 of 11 ICUs and varied from -1.23 days to 4.69 days. A reduction in length of stay in Mexico was probably caused by an increased risk of death due to CLABSI, leading to shorter times to death. Adjusting for patient age and Average Severity of Illness Score tended to increase the estimated excess length of stays due to CLABSI.

CLABSIs are associated with an excess length of ICU stay. The average excess length of stay varies between ICUs, most likely because of the case-mix of admissions and differences in the ways that hospitals deal with infections.

There are limited data comparing the clinical presentations, comorbidities, and outcomes of patients with infections due to seasonal influenza with patients with infections due to pandemic (H1N1) 2009 influenza.

To compare the epidemiological characteristics and outcomes of pandemic (H1N1) 2009 influenza with those of seasonal influenza.

A cross-sectional study was conducted among patients who received diagnoses during emergency department and inpatient encounters at 2 affiliated academic medical centers in Philadelphia, Pennsylvania. Cases of seasonal influenza during the period November 1, 2005, through June 1, 2008, and cases of pandemic influenza during the period from May 1, 2009, through August 7, 2009, were identified retrospectively.

Forty-nine cases of pandemic influenza and 503 cases of seasonal influenza were identified. Patients with pandemic H1N1 were younger (median age, 29 years) than patients with seasonal influenza (median age, 59 years) (P <.001). More patients with pandemic H1N1 (35 [71%] of 49) were African American, compared with patients with seasonal influenza (267 [53%] of 503; P = .02). Several symptoms were more common among patients with pandemic influenza infections than among patients with seasonal influenza infections: cough (98% vs 83%; P = .007), myalgias (71% vs 46%; P = .001), and pleuritic chest pain (45% vs 15%; P < .001). Pregnancy was the only comorbidity that occurred significantly more often in the pandemic influenza group than in the seasonal influenza group (16% vs 1%; P < .001). There were no significant differences in frequencies of deaths of hospitalized patients, intensive care unit admission, or length of hospitalization between groups.

Other than pregnancy, there were few clinically important differences between infections due to seasonal influenza and those due to pandemic influenza. The greater rate of lower respiratory tract symptoms in pandemic cases might serve to differentiate pandemic influenza from seasonal influenza.

States, including Illinois, have passed legislation mandating the use of International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes for reporting healthcare-associated infections, such as methicillin-resistant Staphylococcus aureus (MRSA).

To evaluate the sensitivity of ICD-9-CM code combinations for detection of MRSA infection and to understand implications for reporting.

We reviewed discharge and microbiology databases from July through August of 2005, 2006, and 2007 for ICD-9-CM codes or microbiology results suggesting MRSA infection at a tertiary care hospital near Chicago, Illinois. Medical records were reviewed to confirm MRSA infection. Time from admission to first positive MRSA culture result was evaluated to identify hospital-onset MRSA (HO-MRSA) infections. The sensitivity of MRSA code combinations for detecting confirmed MRSA infections was calculated using all codes present in the discharge record (up to 15); the effect of reviewing only 9 diagnosis codes, the number reported to the Centers for Medicare and Medicaid Services, was also evaluated. The sensitivity of the combination of diagnosis codes for detection of HO-MRSA infections was compared with that for community-onset MRSA (CO-MRSA) infections.

We identified 571 potential MRSA infections with the use of screening criteria; 403 (71%) were confirmed MRSA infections, of which 61 (15%) were classified as HO-MRSA. The sensitivity of MRSA code combinations was 59% for all confirmed MRSA infections when 15 diagnoses were reviewed compared with 31% if only 9 diagnoses were reviewed (P < .001). The sensitivity of code combinations was 33% for HO-MRSA infections compared with 62% for CO-MRSA infections (P < .001).

Limiting analysis to 9 diagnosis codes resulted in low sensitivity. Furthermore, code combinations were better at revealing CO-MRSA infections than HO-MRSA infections. These limitations could compromise the validity of ICD-9-CM codes for interfacility comparisons and for reporting of healthcare-associated MRSA infections.

To determine the anatomic sites and natural history of colonization with gram-negative multidrug-resistant organisms (MDROs).

Prospective, longitudinal cohort study.

Walter Reed Army Medical Center, a 236-bed tertiary care center in Washington, DC.

Deployed subjects (ie, inpatients medically evacuated from Iraq or Afghanistan) or nondeployed subjects admitted to the same hospital.

Consenting patients had 6 anatomic sites cultured every 3 days for 2 weeks and then weekly. Gram-negative organisms resistant to 3 or more classes of antibiotics were considered MDROs. Isolates were genotyped using pulsed-field gel electrophoresis. Clinical data, data on antibiotic use, and clinical culture results were collected.

Of 60 deployed subjects, 14 (23%) were colonized with an MDRO at admission, and 13 (22%) had incident colonization during hospitalization. The groin was the most sensitive anatomic site for detecting MDRO colonization, and all but one subject remained colonized for the duration of their hospitalization. Sixty percent of subjects with incident Acinetobacter colonization and 25% of subjects with incident Klebsiella colonization had strains that were related to those isolated from other subjects. Of 60 nondeployed subjects, 5 (8%) were colonized with an MDRO at admission; all had recent healthcare contact, and 1 nondeployed subject had an isolate related to a strain recovered from a deployed subject.

Colonization with gram-negative MDROs is common among patients with war-related trauma admitted to a military hospital and also occurs among nondeployed patients with recent healthcare contact. The groin is the most sensitive anatomic site for active surveillance, and spontaneous decolonization is rare.

Certain emerging infections, such as severe acute respiratory syndrome and avian influenza, represent a great risk to healthcare workers (HCWs). There are few data about the epidemiology of H1N1 influenza among HCWs.

We conducted a prospective surveillance study for all HCWs at King Abdulaziz Medical City (Riyadh, Saudi Arabia) who were confirmed positive for H1N1 influenza by polymerase chain reaction (PCR) from June 1 through November 30, 2009.

During 6 months of surveillance, 526 HCWs were confirmed positive for H1N1 influenza. The distribution of these cases showed 2 clear outbreaks: an initial outbreak (peak at early August) and a shorter second wave (peak at end of October). Among all PCR-confirmed cases, the attack rate was significantly higher in clinical HCWs than in nonclinical HCWs (6.0% vs 4.3%; P < .001 ) and in HCWs in emergency departments than in HCWs in other hospital locations (17.4% vs 5.0%, P < .001). The percentage of HCWs who received regular influenza vaccination was greater for clinical HCWs than for nonclinical HCWs (46.2% vs 24.6%; P < .001). The majority of HCWs with confirmed H1N1 influenza were young (mean age ± standard deviation, 34.5 ± 9.5 years), not Saudi (58.4%), female (55.1%), and nurses (36.1%). Approximately 4% of women who were less than 50 years old were pregnant. Reported exposures included contact with a case (41.0%), contact with a sick household member (23.8%), and recent travel history (13.3%). Respiratory symptoms (98.0%), including cough (90.1%), were the most frequently reported symptoms, followed by muscle aches (66.2%), fever (62.5%), headache (57.9%), diarrhea (16.5%), and vomiting (9.8%). None of these HCWs died, and all recovered fully without hospital admission.

The results confirm the vulnerability of HCWs, whether clinical or nonclinical, to emerging H1N1 influenza.

To define the utility of using routine diagnostic methods to detect influenza in older, hospitalized adults.

Descriptive study.

One academic hospital and 1 community hospital during the 2006–2007 and 2007–2008 influenza seasons.

Hospitalized adults 50 years of age or older.

Adults who were 50 years of age or older and hospitalized with symptoms of respiratory illness were enrolled and tested for influenza by use of reverse-transcriptase polymerase chain reaction (RT-PCR). Using RT-PCR as the gold standard, we assessed the performances of rapid antigen tests and conventional influenza culture and the diagnostic use of the clinical definition of influenza-like illness.

Influenza was detected by use of RT-PCR in 26 (11%) of 228 patients enrolled in our study. The sensitivity of the rapid antigen test performed at bedside by research staff members was 19.2% (95% confidence interval, 8.51%–37.9%); the sensitivity of conventional influenza culture was 34.6% (95% confidence interval, 19.4%–53.8%). The ability to detect influenza with both the rapid antigen test and culture was associated with patients with a higher viral load (P = .002 and P = .001, respectively). The ability to diagnose influenza by use of the clinical definition of influenza-like illness had a higher sensitivity (80.8%) but lacked specificity (40.6%).

Because rapid antigen testing and viral culture have poor sensitivity (19.2% and 34.6%, respectively), neither testing method is sufficient to use to determine what type of isolation procedures to implement in a hospital setting.

To evaluate the effectiveness of a positive deviance strategy for the improvement of hand hygiene compliance in 2 adult step-down units.

A 9-month, controlled trial comparing the effect of positive deviance on compliance with hand hygiene.

Two 20-bed step-down units at a tertiary care private hospital.

The first phase of our study was a 3-month baseline period (from April to June 2008) in which hand hygiene episodes were counted by use of electronic handwashing counters. From July to September 2008 (ie, the second phase), a positive deviance strategy was implemented in the east unit; the west unit was the control unit. During the period from October to December 2008 (ie, the third phase), positive deviance was applied in both units.

During the first phase, there was no statistically significant difference between the 2 step-down units in the number of episodes of hand hygiene per 1,000 patient-days or in the incidence density of healthcare-associated infections (HAIs) per 1,000 patient-days. During the second phase, there were 62,000 hand hygiene episodes per 1,000 patient-days in the east unit and 33,570 hand hygiene episodes per 1,000 patient-days in the west unit (P < .01). The incidence density of HAIs per 1,000 patient-days was 6.5 in the east unit and 12.7 in the west unit (P = .04). During the third phase, there was no statistically significant difference in hand hygiene episodes per 1,000 patient-days (P = .16) or in incidence density of HAIs per 1,000 patient-days.

A positive deviance strategy yielded a significant improvement in hand hygiene, which was associated with a decrease in the overall incidence of HAIs.

To determine the prevalence of asymptomatic carriage of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) among healthcare professionals (HCPs) who experience varying degrees of exposure to ambulatory patients and to genetically characterize isolates.

This single-center, cross-sectional study enrolled 256 staff from the intensive care units, emergency department, and prehospital services of an urban tertiary care university hospital in 2008. Occupational histories and nasal samples for S. aureus cultures were obtained. S. aureus isolates were genetically characterized with the use of spa typing and screened for mecA. MRSA isolates underwent further characterization.

S. aureus was isolated from 112 of 256 (43.8%) HCPs, including 30 of 52 (57.7%) paramedics, 51 of 124 (41.1%) nurses, 11 of 28 (39.3%) clerical workers, and 20 of 52 (38.5%) physicians. MRSA was isolated from 17 (6.6%) HCPs, including 1 (1.9%) paramedic, 13 (10.5%) nurses, 1 (3.6%) clerical worker, and 2 (3.8%) physicians. Among S. aureus isolates, 15.2% were MRSA. MRSA prevalence was 9.6% (12/125) in emergency department workers, 5.1% (4/79) in intensive care unit workers, and 1.9% (1/52) in emergency medical services workers. Compared with paramedics, who had the lowest prevalence of methicillin resistance among S. aureus isolates (1 of 30 [3.3%] isolates), nurses, who had the highest prevalence (13 of 51 [25.4%] isolates), had an odds ratio of 9.92 (95% confidence interval, 1.32-435.86; P = .02) for methicillin resistance. Analysis of 15 MRSA isolates revealed 7 USA100 strains, 6 USA300 strains, 1 USA800 strain, and 1 EMRSA-15 strain. All USA300 strains were isolated from emergency department personnel.

The observed prevalence of S. aureus and MRSA colonization among HCPs exceeds previously reported prevalences in the general population. The proportion of community-associated MRSA among all MRSA in this colonized HCP cohort reflects the distribution of the USA300 community-associated strain observed increasingly among US hospitalized patients.

To reduce the rate of late-onset sepsis in a neonatal intensive care unit (NICU) by decreasing the rate of central line–associated bloodstream infection (CLABSI).

We conducted a quasi-experimental study of an educational intervention designed to improve the quality of clinical practice in an NICU. Participants included all NICU patients with a central venous catheter (CVC). Data were collected during the period from July 1, 2005, to June 30, 2007, to document existing CLABSI rates and CVC-related practices. A multidisciplinary quality improvement committee was established to review these and published data and to create guidelines for CVC placement and management. Educational efforts were conducted to implement these practices. Postintervention CLABSI rates were collected during the period from January 1, 2008, through March 31, 2009, and compared with preintervention data and with benchmark data from the National Healthcare Safety Network (NHSN).

The rate of CLABSI in the NICU decreased from 8.40 to 1.28 cases per 1,000 central line–days (adjusted rate ratio, 0.19 [95% confidence interval, 0.08–0.45]). This rate was lower than the NHSN benchmark rate for level III NICUs. The overall rate of late-onset sepsis was reduced from 5.84 to 1.42 cases per 1,000 patient-days (rate difference, −4.42 cases per 1,000 patient-days [95% confidence interval, −5.55 to −3.30 cases per 1,000 patient-days]).

It is possible to reduce the rate of CLABSI, and therefore the rate of late-onset sepsis, by establishing and adhering to evidence-based guidelines. Sustainability depends on continued data surveillance, knowledge of medical and nursing literature, and timely feedback to the staff. The techniques established are applicable to other populations and areas of inpatient care.

To evaluate the long-term impact of successive interventions on rates of methicillin-resistant Staphylococcus aureus (MRSA) colonization or infection and MRSA bacteremia in an endemic hospital-wide situation.

Quasi-experimental, interrupted time-series analysis. The impact of the interventions was analyzed by use of segmented regression. Representative MRSA isolates were typed by use of pulsed-field gel electrophoresis.

A 950-bed teaching hospital in Seville, Spain.

All patients admitted to the hospital during the period from 1995 through 2008.

Three successive interventions were studied: (1) contact precautions, with no active surveillance for MRSA; (2) targeted active surveillance for MRSA in patients and healthcare workers in specific wards, prioritized according to clinical epidemiology data; and (3) targeted active surveillance for MRSA in patients admitted from other medical centers.

Neither the preintervention rate of MRSA colonization or infection (0.56 cases per 1,000 patient-days [95% confidence interval {CI}, 0.49-0.62 cases per 1,000 patient-days]) nor the slope for the rate of MRSA colonization or infection changed significantly after the first intervention. The rate decreased significantly to 0.28 cases per 1,000 patient-days (95% CI, 0.17-0.40 cases per 1,000 patient-days) after the second intervention and to 0.07 cases per 1,000 patient-days (95% CI, 0.06-0.08 cases per 1,000 patient-days) after the third intervention, and the rate remained at a similar level for 8 years. The MRSA bacteremia rate decreased by 80%, whereas the rate of bacteremia due to methicillin-susceptible S. aureus did not change. Eighty-three percent of the MRSA isolates identified were clonally related. All MRSA isolates obtained from healthcare workers were clonally related to those recovered from patients who were in their care.

Our data indicate that long-term control of endemic MRSA is feasible in tertiary care centers. The use of targeted active surveillance for MRSA in patients and healthcare workers in specific wards (identified by means of analysis of clinical epidemiology data) and the use of decolonization were key to the success of the program.

To use social network analysis to design more effective strategies for vaccinating healthcare workers against influenza.

An agent-based simulation.

A simulation based on a 700-bed hospital.

We first observed human contacts (defined as approach within approximately 0.9 m) performed by 15 categories of healthcare workers (eg, floor nurses, intensive care unit nurses, staff physicians, phlebotomists, and respiratory therapists). We then constructed a series of contact graphs to represent the social network of the hospital and used these graphs to run agent-based simulations to model the spread of influenza. A targeted vaccination strategy that preferentially vaccinated more “connected” healthcare workers was compared with other vaccination strategies during simulations with various base vaccination rates, vaccine effectiveness, probability of transmission, duration of infection, and patient length of stay.

We recorded 6,654 contacts by 148 workers during 606 hours of observations from January through December 2006. Unit clerks, X-ray technicians, residents and fellows, transporters, and physical and occupational therapists had the most contacts. When repeated contacts with the same individual were excluded, transporters, unit clerks, X-ray technicians, physical and occupational therapists, and social workers had the most contacts. Preferentially vaccinating healthcare workers in more connected job categories yielded a substantially lower attack rate and fewer infections than a random vaccination strategy for all simulation parameters.

Social network models can be used to derive more effective vaccination policies, which are crucial during vaccine shortages or in facilities with low vaccination rates. Local vaccination priorities can be determined in any healthcare facility with only a modest investment in collection of observational data on different types of healthcare workers. Our findings and methods (ie, social network analysis and computational simulation) have implications for the design of effective interventions to control a broad range of healthcare-associated infections.

To compare use of chlorhexidine with use of iodine for preoperative skin antisepsis with respect to effectiveness in preventing surgical site infections (SSIs) and cost.

We searched the Agency for Healthcare Research and Quality website, the Cochrane Library, Medline, and EMBASE up to January 2010 for eligible studies. Included studies were systematic reviews, meta-analyses, or randomized controlled trials (RCTs) comparing preoperative skin antisepsis with chlorhexidine and with iodine and assessing for the outcomes of SSI or positive skin culture result after application. One reviewer extracted data and assessed individual study quality, quality of evidence for each outcome, and publication bias. Meta-analyses were performed using a fixed-effects model. Using results from the meta-analysis and cost data from the Hospital of the University of Pennsylvania, we developed a decision analytic cost-benefit model to compare the economic value, from the hospital perspective, of antisepsis with iodine versus antisepsis with 2 preparations of chlorhexidine (ie, 4% chlorhexidine bottle and single-use applicators of a 2% chlorhexidine gluconate [CHG] and 70% isopropyl alcohol [IPA] solution), and also performed sensitivity analyses.

Nine RCTs with a total of 3,614 patients were included in the meta-analysis. Meta-analysis revealed that chlorhexidine antisepsis was associated with significantly fewer SSIs (adjusted risk ratio, 0.64 [95% confidence interval, [0.51–0.80]) and positive skin culture results (adjusted risk ratio, 0.44 [95% confidence interval, 0.35–0.56]) than was iodine antisepsis. In the cost-benefit model baseline scenario, switching from iodine to chlorhexidine resulted in a net cost savings of $16-$26 per surgical case and $349,904–$568,594 per year for the Hospital of the University of Pennsylvania. Sensitivity analyses showed that net cost savings persisted under most circumstances.

Preoperative skin antisepsis with chlorhexidine is more effective than preoperative skin antisepsis with iodine for preventing SSI and results in cost savings.

To identify the determinants of influenza vaccination and the moderators of the intention-behavior relationship among healthcare workers (HCWs).

Prospective survey with 2-month follow-up.

Three university-affiliated public hospitals.

Random sample of 424 HCWs.

The intention of an HCW to get vaccinated against influenza was measured by means of a self-administered questionnaire based on an extended version of the theory of planned behavior. An objective measure of behavior was extracted 2 months later from the vaccination database of the hospitals.

Controlling for past behavior, we found that the determinants of influenza vaccination were intention (odds ratio [OR], 8.32 [95% confidence interval {CI}, 2.82–24.50]), moral norm (OR, 3.01 [95% CI, 1.17–7.76]), anticipated regret (OR, 2.33 [95% CI, 1.23–4.41]), and work status (ie, full time vs part time; OR, 1.99 [95% CI, 1.92–3.29]). Moral norm also interacted with intention as a significant moderator of the intention-behavior relationship (OR, 0.09 [95% CI, 0.03–0.30]). Again, apart from the influence of past behavior, intention to get vaccinated was predicted by use of the following variables: attitude (ß = .32; P < .001), professional norm (β = .18; P < .001), moral norm (β = .18; P < .001), subjective norm (ß = .09; P < .001), and self-efficacy (ß = .08; P < .001). This latter model explained 89% of the variance in HCWs' intentions to get vaccinated against influenza during the next vaccination campaign.

Our study suggests that influenza vaccination among HCWs is mainly a motivational issue. In this regard, it can be suggested to reinforce the idea that getting vaccinated can reduce worry and protect family members.