To develop and validate a risk prediction model that could identify patients at high risk for Clostridium difficile infection (CDI) before they develop disease.

Retrospective cohort study in a tertiary care medical center.

Patients admitted to the hospital for at least 48 hours during the calendar year 2003.

Data were collected electronically from the hospital's Medical Informatics database and analyzed with logistic regression to determine variables that best predicted patients' risk for development of CDI. Model discrimination and calibration were calculated. The model was bootstrapped 500 times to validate the predictive accuracy. A receiver operating characteristic curve was calculated to evaluate potential risk cutoffs.

A total of 35,350 admitted patients, including 329 with CDI, were studied. Variables in the risk prediction model were age, CDI pressure, times admitted to hospital in the previous 60 days, modified Acute Physiology Score, days of treatment with high-risk antibiotics, whether albumin level was low, admission to an intensive care unit, and receipt of laxatives, gastric acid suppressors, or antimotility drugs. The calibration and discrimination of the model were very good to excellent (C index, 0.88; Brier score, 0.009).

The CDI risk prediction model performed well. Further study is needed to determine whether it could be used in a clinical setting to prevent CDI-associated outcomes and reduce costs.

To study the frequency of isolation of Acinetobacter baumannii complex (ABC) and methicillin-resistant Staphylococcus aureus (MRSA) from surfaces of rooms newly vacated by patients with multidrug-resistant (MDR) ABC following various rounds of routine terminal cleaning and disinfection (C/D) with bleach or 1 round of C/D followed by hydrogen peroxide vapor (HPV) treatment.

A 900-bed tertiary care hospital.

ABC and MRSA cultures were obtained from hospital rooms including 312 rooms (mean, 18.3 sites/room) following 4 rounds of C/D, 37 rooms (mean, 20 sites/room) following 1 round of C/D before and after HPV treatment, and 134 rooms (mean, 20 sites/room) following 1 round of C/D and HPV treatment.

Following 4 rounds of C/D, 83 (26.6%) rooms had 1 or more culture-positive sites; 102 (1.8%) sites in 51 (16.4%) rooms grew ABC, and 108 (1.9%) sites in 44 (14.1%) rooms grew MRSA. The addition of HPV treatment to 1 round of C/D resulted in a significant drop in ABC- and MRSA-positive room sites (odds ratio, 0 [95% confidence interval, 0–0.8]; P = .04 for both organisms). Following 1 round of C/D and HPV treatment, 6 (4.5%) rooms were culture-positive for ABC, MRSA, or both.

Routine terminal C/D of hospital rooms vacated by MDRABC-positive patients may be associated with a significant number of ABC- or MRSA-positive room surfaces even when up to 4 rounds of C/D are performed. The addition of HPV treatment to 1 round of C/D appears effective in reducing the number of persistently contaminated room sites in this setting.

We report a meta-analysis of 4 identical time-series cohort studies of the impact of switching from use of open infusion containers (glass bottle, burette, or semirigid plastic bottle) to closed infusion containers (fully collapsible plastic containers) on central line-associated bloodstream infection (CLABSI) rates and all-cause intensive care unit (ICU) mortality in 15 adult ICUs in Argentina, Brazil, Italy, and Mexico.

All ICUs used open infusion containers for 6–12 months, followed by switching to closed containers. Patient characteristics, adherence to infection control practices, CLABSI rates, and ICU mortality during the 2 periods were compared by χ2 test for each country, and the results were combined using meta-analysis.

Similar numbers of patients participated in 2 periods (2,237 and 2,136). Patients in each period had comparable Average Severity of Illness Scores, risk factors for CLABSI, hand hygiene adherence, central line care, and mean duration of central line placement. CLABSI incidence dropped markedly in all 4 countries after switching from an open to a closed infusion container (pooled results, from 10.1 to 3.3 CLABSIs per 1,000 central line-days; relative risk [RR], 0.33 [95% confidence interval {CI}, 0.24-0.46]; P<.001). All-cause ICU mortality also decreased significantiy, from 22.0 to 16.9 deaths per 100 patients (RR, 0.77 [95% CI, 0.68-0.87]; P<.001).

Switching from an open to a closed infusion container resulted in a striking reduction in the overall CLABSI incidence and all-cause ICU mortality. Data suggest that open infusion containers are associated with a greatiy increased risk of infusion-related bloodstream infection and increased ICU mortality that have been unrecognized. Furthermore, data suggest CLABSIs are associated with significant attributable mortality.

To describe the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) carriage and transmission in an ambulatory hemodialysis population.

Prospective cohort study.

Outpatient hemodialysis facility affiliated with a large academic medical center.

Of the 170 facility patients, 103 (61%) participated in the study.

Swab specimens of the nares, axillae, and vascular access site were collected from participants weekly for 3 weeks and then monthly for 5 months. Demographic and clinical data were collected monthly for 12 months. Molecular analysis of MRSA isolates was performed.

The baseline MRSA carriage prevalence was 12%. Factors associated with MRSA carriage included a history of MRSA; failed renal transplantation; hospital admission within 6 months; and receipt of a first-generation cephalosporin, cefepime, or vancomycin. Six subjects acquired MRSA after enrollment (incidence, 1.2 per 100 patient-months at-risk; overall prevalence, 18%). Molecular analysis suggested that transmission occurred within the facility. The incidence of MRSA infection among carriers was 1.76 per 100 patient-months. Community-associated strains (ie, USA300) were isolated from 28% of carriers and at least 25% of infections.

The prevalence of MRSA carriage and the incidence of infection among carriers were high among ambulatory hemodialysis patients, and community-associated MRSA was responsible for a large portion of the MRSA burden. A relatively high rate of MRSA acquisition was observed, with indirect evidence of intrafacility transmission. Additional studies are needed to confirm these findings and to identify effective and feasible methods to prevent MRSA transmission and infection among hemodialysis patients.

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.

To describe the implementation of an institution-wide, multiple-step intervention to curtail the epidemic spread of carbapenem-resistant Klebsiella pneumoniae (CRKP).

Consecutive intervention analyses.

All patients admitted to a 775-bed tertiary care medical center in Jerusalem, Israel, from 2006 through 2010.

The effects of 4 interventions were assessed: (1) a policy of isolation for patients colonized or infected with CRKP in single rooms, which was started in March 2006; (2) cohorting of CRKP patients with dedicated nursing staff and screening of patients neighboring a patient newly identified as a carrier of CRKP, which was started in March 2007; (3) weekly active surveillance of intensive care unit patients, which was started during August 2008; and (4) selective surveillance of patients admitted to the emergency department, which was started in March 2009. Interrupted regression analysis and change-point analysis were used to assess the effect of each intervention on the CRKP epidemic.

Patient isolation alone failed to control the spread of CRKP, with incidence increasing to a peak of 30 new cases per 1,000 hospital beds per month. Institution of patient cohorting led to a steep decline in the incidence of CRKP acquisition (P< .001). Introduction of active surveillance interventions was followed by a decrease in the incidence of CRKP-positive clinical cultures but an increase in the incidence of CRKP-positive screening cultures. The mean prevalence of CRKP positivity for the period after cohorting began showed a statistically significant change from the mean prevalence in the preceding period (P< .001).

The cohorting of patients with dedicated staff, combined with implementation of focused active surveillance, effectively terminated the epidemic spread of CRKP. Cohorting reduced cross-infection within the hospital, and active surveillance allowed for earlier detection of carrier status. Both interventions should be considered in attempts to contain a hospital epidemic.

To evaluate the impact of ertapenem use in Pseudomonas aeruginosa carbapenem resistance, taking into account the volume of antimicrobial consumption, the consumption by the entire hospital of alcohol-based antiseptic hand rub, and the density rate of invasive practices.

Before-and-after trial.

A tertiary care university hospital in southern Brazil.

Ertapenem was first added to the hospital formulary in June 2006, and it was excluded in February 2009. We evaluated Pseudomonas aeruginosa resistance rates through 3 study periods: period 1, before ertapenem use (17 months); period 2, during ertapenem use (33 months); and period 3, after exclusion of ertapenem (15 months).

After introduction of ertapenem, there was a significant decrease in median consumption of imipenem or meropenem, from 2.6 to 2.2 defined daily doses (DDDs) per 100 patient-days (level change from 0.04 to -1.08; P < .01), and an increase in the use of these medications after ertapenem exclusion, from 2.2 to 3.3 DDDs per 100 patient-days (level change from -0.14 to 0.91; P < .01), by segmented regression analysis. There was no difference in the incidence density of carbapenem-resistant P. aeruginosa infection related to ertapenem use throughout the study periods. However, by multiple regression analysis, the reduction in the rate of carbapenem-resistant P. aeruginosa infection correlated significantly with the increase in the volume of alcohol used as hand sanitizer, which was from 660.7 mL per 100 patient-days in period 1 to 2,955.1 mL per 100 patient-days in period 3 (P = .04). Ertapenem use did not impact the rate of carbapenem-resistant P. aeruginosa infection.

Use of alcohol-based hand gel, rather than ertapenem, was associated with a reduction in the rates of carbapenem-resistant P. aeruginosa infection. Measures to reduce resistance must include factors other than just antimicrobial stewardship programs alone.

To estimate the proportion of patients who acquire methicillin-resistant Staphylococcus aureus (MRSA) while in hospital and to identify risk factors associated with acquisition of MRSA.

Retrospective cohort study.

Adult patients discharged from 36 general specialty wards of 2 Scottish hospitals that had implemented universal screening for MRSA on admission.

Patients were screened for MRSA on discharge from hospital by using multisite body swabs that were tested by culture. Discharge screening results were linked to admission screening results. Genotyping was undertaken to identify newly acquired MRSA in MRSA-positive patients on admission.

Of the 5,155 patients screened for MRSA on discharge, 2.9% (95% confidence interval [CI], 2.43–3.34) were found to be positive. In the subcohort screened on both admission and discharge (n = 2,724), 1.3% of all patients acquired MRSA while in hospital (incidence rate, 2.1/1,000 hospital bed-days in this cohort [95% CI, 1.5–2.9]), while 1.3% remained MRSA positive throughout hospital stay. Three risk factors for acquisition of MRSA were identified: age above 64 years, self-reported renal failure, and self-reported presence of open wounds. On a population level, the prevalence of MRSA colonization did not differ between admission and discharge.

Cross-transmission of MRSA takes place in Scottish hospitals that have implemented universal screening for MRSA. This study reinforces the importance of infection prevention and control measures to prevent MRSA cross-transmission in hospitals; universal screening for MRSA on admission will in itself not be sufficient to reduce the number of MRSA colonizations and subsequent MRSA infections.

The present study investigated regional variations in antibiotic use for the treatment of hospital-acquired infections (HAIs) in France by means of a multilevel analysis, to identify targets for quality improvement.

Data were obtained from the 2001 and 2006 French national point-prevalence surveys of HAIs and antibiotic use. The present study was conducted using data from 393 nonteaching public hospitals. Data included patient characteristics calculated at the hospital level (mean age and proportion of patients with the following: HAI, presence of a vascular catheter, presence of a urinary catheter, surgical procedure, and immunodeficiency) and hospital characteristics (size and presence of an intensive care unit). The regional effect was measured using a random intercept on a regional variable.

Overall, the prevalence of antibiotic use was 5.35% for both study years. The most commonly used antibiotics for HAIs were fluoroquinolones (2001, 1.33%; 2006, 1.35%) and combinations of penicillins with a β-lactamase inhibitor (2001, 0.92%; 2006, 1.02%). Mapping of antibiotic use showed wide variation between regions. The regional effect explained 3% of antibiotic variation in the unadjusted analysis. In the multivariable analysis, hospital size, high prevalence of patients with immunodeficiency, and infection characteristics explained 45% of the variability in antibiotic use. The regional effect was not retained in the final model.

The pattern of antibiotic use for HAIs differed over time, and regional variations were mostly explained by patient characteristics; there was no regional effect. Models that take data hierarchy into account are essential to better approach antibiotic use and develop relevant strategies for improvement.

Electronic measures of surgical site infections (SSIs) are being used more frequently in place of labor-intensive measures. This study compares performance characteristics of 2 electronic measures of SSIs with a clinical measure and studies the implications of using electronic measures to estimate risk factors and costs of SSIs among surgery patients.

Data included 1,066 general and vascular surgery patients at a single academic center between 2007 and 2008. Clinical data were from the National Surgical Quality Improvement Program (NSQIP) database, which includes a nurse-derived measure of SSI. We compared the NSQIP SSI measure with 2 electronic measures of SSI: MedMined Nosocomial Infection Marker (NIM) and International Classification of Diseases, Ninth Revision (ICD-9) coding for SSIs. We compared infection rates for each measure, estimated sensitivity and specificity of electronic measures, compared effects of SSI measures on risk factors for mortality using logistic regression, and compared estimated costs of SSIs for measures using linear regression.

SSIs were observed in 8.8% of patients according to the NSQIP definition, 2.6% of patients according to the NIM definition, and 5.8% according to the ICD-9 definition. Logistic regression for each SSI measure revealed large differences in estimated risk factors. NIM and ICD-9 measures overestimated the cost of SSIs by 134% and 33%, respectively.

Caution should be taken when relying on electronic measures for SSI surveillance and when estimating risk and costs attributable to SSIs. Electronic measures are convenient, but in this data set they did not correlate well with a clinical measure of infection.

To describe the prevalence and characteristics of antimicrobial stewardship programs (ASPs) in hospitals across the United States and to describe financial support provided for these programs.

Electronic and paper 14-question survey of infectious diseases physician members of the Infectious Diseases Society of America Emerging Infections Network (IDSA EIN).

All 1,044 IDSA EIN members who care for adult patients were invited to participate.

Five hundred twenty-two (50%) members responded. Seventy-three percent of respondents reported that their institutions had or were planning an ASP, compared with 50% reporting the same thing in an EIN survey 10 years before. A shift was noted from formulary restriction alone to use of a set of tailored strategies designed to provide information and feedback to prescribers, particularly in community hospitals. Lack of funding and lack of personnel were reported as major barriers to implementing a program. Fifty-two percent of respondents with an ASP reported that infectious diseases physicians do not receive direct compensation for their participation in the ASP, compared with 18% 10 years ago.

The percentage of institutions reporting ASPs has increased over the last decade, although small community hospitals were least likely to have these programs. In addition, ASP strategies have shifted dramatically. Lack of funding remains a key barrier for ASPs, and administrators need additional cost savings data in order to support ASPs. Interestingly, while guidelines and editorials regard compensated participation by an infectious diseases physician in these programs as critical, we found that more than half of the respondents reported no direct compensation for ASP activities.

To compare the impacts of different methicillin-resistant Staphylococcus aureus (MRSA) screening test options (eg, polymerase chain reaction [PCR], rapid culture) and program characteristics on the clinical outcomes and budget of a typical US hospital.

We developed an Excel-based decision-analytic model, using published literature to calculate and compare hospital costs and MRSA infection rates for PCR- or culture-based MRSA screening and then used multivariate sensitivity analysis to evaluate key variables. Same-day PCR testing for a representative 370-bed teaching hospital in the United States was assessed in different populations (high-risk patients, intensive care unit [ICU] patients, or all patients) and compared with other test options.

Different screening program populations (all patients, high-risk patients, ICU patients, or patients with previous MRSA colonization or infection only) represented a potential savings of $12,158-$76,624 per month over no program ($188,618). Analysis of multiple test options in high-risk population screening indicated that same-day PCR testing of high-risk patients resulted in fewer infections over 1,720 patient-days (2.9, compared with 3.5 for culture on selective media and 3.8 for culture on nonselective media) and the lowest total cost ($112,012). The costs of other testing approaches ranged from $113,742 to $123,065. Sensitivity analysis revealed that variations in transmission rate, conversion to infection, prevalence increases, and hospital size are important to determine program impact. Among test characteristics, turnaround time is highly influential.

All screening options showed reductions in infection rates and cost impact improvement over no screening program. Among the options, same-day PCR testing for high-risk patients slightly edges out the others in terms of fewest infections and greatest potential cost savings.

Describe central line-associated bloodstream infection (CLA-BSI) epidemiology in pediatric intensive care units (PICUs).

Descriptive study (29 PICUs); cohort study (18 PICUs).

PICUs in a national improvement collaborative.

Patients admitted October 2006 to December 2007 with 1 or more central lines.

CLA-BSIs were prospectively identified using the National Healthcare Safety Network definition and then readjudicated using the revised 2008 definition. Risk factors for CLA-BSI were examined using age-adjusted, time-varying Cox proportional hazards models.

In the descriptive study, the CLA-BSI incidence was 3.1/1,000 central line-days; readjudication with the revised definition resulted in a 17% decrease. In the cohort study, the readjudicated incidence was 2.0/1,000 central line-days. Ninety-nine percent of patients were CLA-BSI-free through day 7, after which the daily risk of CLA-BSI doubled to 0.27% per day. Compared with patients with respiratory diagnoses (most prevalent category), CLA-BSI risk was higher in patients with gastrointestinal diagnoses (hazard ratio [HR], 2.7 [95% confidence interval {CI}, 1.43-5.16]; P<.002) and oncologic diagnoses (HR, 2.6 [CI, 1.06-6.45]; P=.037). Among all patients, including those with more than 1 central line, CLA-BSI risk was lower among patients with a central line inserted in the jugular vein (HR, 0.43 [CI, 0.30-0.95]; P<.03).

The 2008 CLA-BSI definition change decreased the measured incidence. The daily CLA-BSI risk was very low in patients during the first 7 days of catheterization but doubled thereafter. The risk of CLA-BSI was lower in patients with lines inserted in the jugular vein and higher in patients with gastrointestinal and oncologic diagnoses. These patients are target populations for additional study and intervention.

To estimate the economic value of dispensing preoperative home-based Chlorhexidine bathing cloth kits to orthopedic patients to prevent surgical site infection (SSI).

A stochastic decision-analytic computer simulation model was developed from the hospital’s perspective depicting the decision of whether to dispense the kits preoperatively to orthopedic patients. We varied patient age, cloth cost, SSI-attributable excess length of stay, cost per bed-day, patient compliance with the regimen, and cloth antimicrobial efficacy to determine which variables were the most significant drivers of the model’s outcomes.

When all other variables remained at baseline and cloth efficacy was at least 50%, patient compliance only had to be half of baseline (baseline mean, 15.3%; range, 8.23%–20.0%) for Chlorhexidine cloths to remain the dominant strategy (ie, less costly and providing better health outcomes). When cloth efficacy fell to 10%, 1.5 times the baseline bathing compliance also afforded dominance of the preoperative bath.

The results of our study favor the routine distribution of bathing kits. Even with low patient compliance and cloth efficacy values, distribution of bathing kits is an economically beneficial strategy for the prevention of SSI.

To increase and sustain hospital-wide compliance with hand hygiene through a long-term ongoing multidimensional improvement program emphasizing behavioral factors.

Quasi-experimental short study (August 2000-November 2001) and descriptive time series (April 2003-December 2006).

A 450-bed teaching tertiary-care hospital.

An initial intervention bundle was introduced in pilot locations that addressed cognitive behavioral factors, which included access to alcohol sanitizer, education, and ongoing audit and feedback. The bundle was subsequently disseminated hospital-wide, along with a novel approach focused on behavior modification through positive reinforcement and annually changing incentives.

A total of 36,123 hand hygiene opportunities involving all categories of healthcare workers from 12 inpatient units were observed from October 2000 to October 2006. The rate of compliance with hand hygiene significantly improved after the intervention in 2 cohorts over the first year (from 40% to 64% of opportunities and from 34% to 49% of opportunities; P< .001, compared with the control group). Mean compliance rates ranged from 19% to 41% of 4174 opportunities (at baseline), increased to the highest levels of 73%–84% of 6,420 opportunities 2 years after hospital-wide dissemination, and remained improved at 59%–81% of 4,990 opportunities during year 6 of the program.

This interventional cohort study used a behavioral change approach and is one of the earliest and largest institution-wide programs promoting alcohol sanitizer from the United States that has shown significant and sustained improvements in hand hygiene compliance. This creative campaign used ongoing frequent audit and feedback with novel use of immediate positive reinforcement at an acceptable cost to the institution.

To investigate the effectiveness of a multifaceted hand hygiene program involving the use of pocket-sized containers of antiseptic gel in long-term care facilities (LTCFs) with elderly residents.

In this clustered randomized controlled trial, Hong Kong LTCFs for elderly persons were recruited via snowball sampling. Staff hand hygiene adherence was directly observed, and residents' infections necessitating hospitalization were recorded. After a 3-month preintervention period, LTCFs were randomized to receive pocket-sized containers of alcohol-based gel, reminder materials, and education for all HCWs (treatment group) or to receive basic life support education and workshops for all healthcare workers (HCWs) (control group). A 2-week intervention period (April 1-15, 2007) was followed by 7 months of postintervention observations.

In the 3 treatment LTCFs, adherence to hand rubbing increased from 5 (1.5%) of 333 to 233 (15.9%) of 1,465 hand hygiene opportunities (P = .001) and total hand hygiene adherence increased from 86 (25.8%) of 333 to 488 (33.3%) of 1,465 opportunities (P = .01) after intervention; the 3 control LTCFs showed no significant change. In the treatment group, the incidence of serious infections decreased from 31 cases in 21,862 resident-days (1.42 cases per 1,000 resident-days) to 33 cases in 50,441 resident-days (0.65 cases per 1,000 resident-days) (P = .002), whereas in the control group, it increased from 16 cases in 32,726 resident-days (0.49 cases per 1,000 resident-days) to 85 cases in 81,177 resident-days (1.05 cases per 1,000 resident-days) (P = .004). In the treatment group, the incidence of pneumonia decreased from 0.91 to 0.28 cases per 1,000 resident-days (P = .001) and the death rate due to infection decreased from 0.37 to 0.10 deaths per 1,000 resident-days (P = .01); the control group revealed no significant change.

A hand hygiene program involving the use of pocket-sized containers of antiseptic gel and education could effectively increase adherence to hand rubbing and reduce the incidence of serious infections in LTCFs with elderly residents.

To identify the prevalence and risk factors for complications associated with percutaneously inserted central venous catheters (PICCs) and evaluate the effect of different catheter types and their indwelling time on catheter-related complications.

Retrospective cohort study.

A 49-bed neonatal intensive-care teaching hospital in Taiwan.

Between 2004 and 2007, 518 single-lumen PICCs (defined as “old type”) and 290 PICCs with a stiffening stylet and a thicker introducer (“new type”) were inserted in a total of 534 neonates with a birth body weight of 1,500 g or less.

Independent risk factors of catheter-related sepsis (CRS) were longer duration for PICC placement and PICC inserted at femoral site (compared with nonfemoral sites) (odds ratio [OR], 1.53 [95% confidence interval {CI}, 1.07-2.25]; P = .044). An independent predictor of catheter-related noninfectious complications was time spent for PICC insertion of more than 60 minutes (compared with less than 30 minutes) (OR, 1.96 [95% CI, 1.08-3.53]; P = .026). New-type PICCs were significantly associated with a higher rate of femoral site insertion, catheter-related noninfectious complications, and longer time for successful insertion than old-type PICCs. The hazard rates of CRS according to indwelling time, determined over 5-day periods by survival analysis, showed 0.05% for catheters in place for 4 days or less; 0.27% for 5-9 days; 0.40% for 10-14 days; 0.68% for 15-19 days; 1.18% for 20-24 days; 3.96% for 25-29 days; and 10.45% for 30 or more days.

Different catheters do influence the complication rates. Spending more than 60 minutes for successful PICC insertion and PICCs indwelling for more than 30 days are associated with higher rates of catheter-related complications.

Coagulase-negative staphylococci (CoNS) are the most commonly isolated pathogens in the neonatal intensive care unit (NICU). CoNS infections are associated with increased morbidity, including neurodevelopmental impairment.

To describe the epidemiology of CoNS infections in the NICU. To determine mortality among infants with definite, probable, or possible CoNS infections.

We performed a retrospective cohort study of all blood, urine, and cerebrospinal fluid cultures from samples obtained from infants aged <121 postnatal days.

A total of 248 NICUs managed by the Pediatrix Medical Group from 1997 to 2009.

We identified 16,629 infants with 17,624 episodes of CoNS infection: 1,734 (10%) definite, 3,093 (17%) probable, and 12,797 (73%) possible infections. Infants with a lower gestational age and birth weight had a higher incidence of CoNS infection. When controlling for gestational age, birth weight, and 5-minute Apgar score, we found that infants with definite, probable, or possible CoNS infection had lower mortality (odds ratio [OR], 0.74 [95% confidence interval {CI}: 0.61, 0.89], 0.68 [95% CI, 0.59, 0.79], and 0.69 [95% CI, 0.63, 0.76], respectively) compared with infants who had negative culture results (P<.001). No significant difference in overall mortality was found in infants who had definite CoNS infection compared with those who had probable or possible CoNS infection (OR, 0.93 [95% CI, 0.75, 1.16] and 0.85 [95% CI, 0.70, 1.03], respectively).

CoNS infection was strongly related to lower gestational age and birth weight. Infants with clinical sepsis and culture-positive CoNS infection had lower mortality rates than infants with clinical sepsis and negative blood culture results. No difference in mortality between infants with a diagnosis of definite, probable, or possible CoNS infection was observed.