Microbiology and risk factors for central line-associated bloodstream infections among pediatric oncology outpatients: a single institution experience of 41 cases.

BACKGROUND: Risk factors for central line-associated bloodstream infections (CLABSI) among children with cancer in the outpatient setting remain poorly defined, and the microbiology may differ from hospital-onset CLABSI. MATERIALS AND METHODS: We conducted a matched case-control study of oncology patients followed at the Dana Farber/Children's Hospital Cancer Center. Cases (N=41) were patients with CLABSI as per National Healthcare Safety Network criteria who had not been hospitalized in the preceding 48 hours. For each case we randomly selected 2 oncology outpatients with a central venous catheter and a clinic visit within 30 days of the case subject's CLABSI. Multivariate conditional logistic regression models were used to identify independent risk factors for CLABSI. We compared the microbiology to that of 54 hospital-onset CLABSI occurring at our institution during the study period. RESULTS: Independent predictors of community-onset CLABSI included neutropenia in the prior week (odds ratio 17.46; 95% confidence interval, 4.71-64.67) and tunneled externalized catheter (vs. implantable port; odds ratio 10.30; 95% confidence interval, 2.42-43.95). Nonenteric gram-negative bacteria were more frequently isolated from CLABSI occurring among outpatients. DISCUSSION: Pediatric oncology outpatients with recent neutropenia or tunneled externalized catheters are at increased risk of CLABSI. The microbiology of community-onset CLABSI differs from hospital-onset CLABSI.

Central venous catheter bundle adherence: Kamishibai card (K-card) rounding for central-line-associated bloodstream infection (CLABSI) prevention.

OBJECTIVE: To institute facility-wide Kamishibai card (K-card) rounding for central venous catheter (CVC) maintenance bundle education and adherence and to evaluate its impact on bundle reliability and central-line-associated bloodstream infection (CLABSI) rates. DESIGN: Quality improvement project. SETTING: Inpatient units at a large, academic freestanding children's hospital. PARTICIPANTS: Data for inpatients with a CVC in place for ≥1 day between November 1, 2017 and October 31, 2018 were included. INTERVENTION: A K-card was developed based on 7 core elements in our CVC maintenance bundle. During monthly audits, auditors used the K-cards to ask bedside nurses standardized questions and to conduct medical record documentation reviews in real time. Adherence to every bundle element was required for the audit to be considered "adherent." We recorded bundle reliability prospectively, and we compared reliability and CLABSI rates at baseline and 1 year after the intervention. RESULTS: During the study period, 2,321 K-card audits were performed for 1,051 unique patients. Overall maintenance bundle reliability increased significantly from 43% at baseline to 78% at 12 months after implementation (P < .001). The hospital-wide CLABSI rate decreased from 1.35 during the 12-month baseline period to 1.17 during the 12-month intervention period, but the change was not statistically significant (incidence rate ratio [IRR], 0.87; 95% confidence interval [CI], 0.60-1.24; P = .41). CONCLUSIONS: Hospital-wide CVC K-card rounding facilitated standardized data collection, discussion of reliability, and real-time feedback to nurses. Maintenance bundle reliability increased after implementation, accompanied by a nonsignificant decrease in the CLABSI rate.

Risk factors for central line-associated bloodstream infection in a pediatric cardiac intensive care unit.

OBJECTIVE: To identify risk factors for central line-associated bloodstream infection (BSI) in patients receiving care in a pediatric cardiac intensive care unit. DESIGN: Matched case-control study. SETTING: CICU at Children's Hospital Boston. PATIENTS: Central line-associated BSI cases were identified between April 2004 and December 2006. We identified two randomly selected control patients who had a central vascular catheter and were admitted within 7 days of each index case. MEASUREMENTS AND MAIN RESULTS: Univariate and multivariate conditional logistic regression analyses were used to identify risk factors for central line-associated BSI. In a secondary analysis, risk factors for central line-associated BSI in those cases who underwent cardiac surgery were sought. During the study period, 67 central line-associated BSIs occurred in 61 patients. Independent risk factors for central line-associated BSI were nonelective admission for medical management (odds ratio [OR] = 6.51 [1.58-26.78]), the presence of noncardiac comorbidities (OR = 4.95 [1.49-16.49]), initial absolute neutrophil count <5000 cells/uL (OR = 6.17 [1.39-27.48]), blood product exposure > or =3 units (OR = 5.56 [1.35-22.87]), central line days > or =7 (OR = 6.06 [1.65-21.83]), and use of hydrocortisone (OR = 28.94 [2.55-330.37]). In those patients who underwent cardiac surgery (n = 37 cases and 108 controls), independent risk factors for central line-associated BSI were admission weight < or =5 kg (OR = 3.13 [1.01-9.68]), Pediatric Risk of Mortality III score > or =15 (OR = 3.44 [1.19-9.92]), blood product exposure > or =3 units (OR = 3.38 [1.28-11.76]), and mechanical ventilation for > or =7 days (OR = 4.06 [1.33-12.40]). CONCLUSIONS: Unscheduled medical admissions, presence of noncardiac comorbidities, extended device utilization, and specific medical therapies are independent risk factors for central line-associated BSI in patients receiving care in a pediatric cardiac intensive care unit.

A novel wall water system for cardiopulmonary bypass may reduce the risk of aerosolized infection.

OBJECTIVE: Oxygenators for cardiopulmonary bypass require water flow for their integral heat exchanger. Heater-cooler units are nearly universally used for this requirement. Heater-cooler units pose the risk of aerosolized infection. The Centers for Disease Control and Prevention recommended discontinuing use of Stöckert 3T heater-cooler units (LivaNova PLC, London, United Kingdom) in October 2016 because of this risk. We aimed to reduce the risk of aerosolized infection posed by heater-cooler units by eliminating those devices from our operating rooms. METHODS: The cardiac surgery division collaborated with in-house specialties to engineer a novel wall water system. The design called for service to 4 operating rooms with the actual water mixing valve in an operating room closet. Remote temperature control was mounted next to the heart-lung machine. Primary safety systems built into the water system include 5 µm filtration, pressure regulating and relief valves, flow quantifiers, limits to the hot and chilled input temperatures, and a novel bridge near the heart-lung machine that allows the perfusionist to test the system before patient use and to quickly disconnect the patient in case of system malfunction. In addition, all water line connections can be made with the tubing drained and never under pressure. RESULTS: This novel wall water system has successfully provided heat exchanger water flow on 625 patients undergoing congenital heart surgery requiring cardiopulmonary bypass during its first 9 months of use. CONCLUSIONS: Wall water systems are an option for oxygenator heat exchangers that allow for improved heat exchange performance while reducing the risk of heater-cooler unit-associated infection during cardiac surgery.

Enhanced central venous catheter bundle for pediatric parenteral-dependent intestinal failure.

BACKGROUND: Central line-associated bloodstream infections (CLABSIs) cause substantial morbidity and increase antimicrobial use and length of stay among hospitalized children in the United States. CLABSI occurs more frequently among high-risk pediatric patients, such as those with intestinal failure (IF) who are parenteral nutrition (PN) dependent. Following an increase in CLABSI rates, a quality improvement (QI) initiative was implemented. METHODS: Using QI methodology, an enhanced central venous catheter (CVC) maintenance bundle was developed and implemented on 2 units for pediatric PN-dependent patients with IF. CLABSI rates were prospectively monitored pre- and postimplementation, and bundle element adherence was monitored. Enhanced bundle elements included chlorhexidine-impregnated patch, daily bathing, ethanol locks, 2 nurses for CVC care in a distraction-free zone, peripheral laboratory draws, bundling routine laboratory tests, and PN administration set changes every 24 hours. RESULTS: Adherence to enhanced bundle elements increased to >90% over 3 months. CLABSI rates averaged 1.41 per 1,000 central line days preimplementation compared with 0.40 per 1,000 device days postimplementation (P = .003), an 85% absolute reduction in CLABSI rates over 12 months. CONCLUSIONS: Patients with IF are at an increased risk for CLABSI. Enhanced CVC maintenance bundles that specifically target prevention practices in this population may be beneficial.

Association Between Storage Interval and Contamination of Reprocessed Flexible Endoscopes in a Pediatric Gastrointestinal Procedural Unit.

OBJECTIVE The maximum safe storage interval after endoscope reprocessing remains unknown. We assessed the association between storage interval and endoscope contamination to evaluate the need for scope reprocessing prior to use. METHODS We conducted a study in 2 phases. In phase 1, we cultured 9 gastrointestinal (GI) endoscopes that had been stored for at least 7 days since reprocessing. Each scope was cultured in 3 places: external surfaces of hand piece, insertion tube, and internal channels. In phase 2, after reprocessing these scopes, we hung and cultured them prospectively in a similar fashion at 1-, 2-, 4-, 6-, and 8-week intervals without patient use. We defined clinically relevant contamination as >100 colony-forming units per milliliter (CFU/mL). RESULTS In phase 1, median hang time was 69 days (range, 8-555 days). Considering the 27 total cultures, 3 of 27 GI endoscopes (11.1%) had positive cultures, all with nonpathogenic skin flora at ≤100 CFU/mL. Median hang time was not statistically different between scopes with positive and negative cultures (P=.82). In phase 2, 7 of 131 prospective cultures (5.3%) from 6 of 9 GI endoscopes at varying storage intervals were positive, all at ≤100 CFU/mL. At 56 days after reprocessing (the longest storage interval studied), 1 of 24 cultures (4.2%) was positive (100 CFU/mL of Bacillus species from external biopsy/suction ports). CONCLUSIONS No endoscopes demonstrated clinically relevant contamination at hang times ranging from 7 to 555 days, and most scopes remained uncontaminated up to 56 days after reprocessing. Our data suggest that properly cleaned and disinfected GI endoscopes could be stored safely for longer intervals than currently recommended. Infect. Control Hosp. Epidemiol. 2017;38:131-135.

Postoperative Infection in Developing World Congenital Heart Surgery Programs: Data From the International Quality Improvement Collaborative.

BACKGROUND: Postoperative infections contribute substantially to morbidity and mortality after congenital heart disease surgery and are often preventable. We sought to identify risk factors for postoperative infection and the impact on outcomes after congenital heart surgery, using data from the International Quality Improvement Collaborative for Congenital Heart Surgery in Developing World Countries. METHODS AND RESULTS: Pediatric cardiac surgical cases performed between 2010 and 2012 at 27 participating sites in 16 developing countries were included. Key variables were audited during site visits. Demographics, preoperative, procedural, surgical complexity, and outcome data were analyzed. Univariate and multivariable logistic regression were used to identify risk factors for infection, including bacterial sepsis and surgical site infection, and other clinical outcomes. Standardized infection ratios were computed to track progress over time. Of 14 545 cases, 793 (5.5%) had bacterial sepsis and 306 (2.1%) had surgical site infection. In-hospital mortality was significantly higher among cases with infection than among those without infection (16.7% versus 5.3%; P<0.001), as were postoperative ventilation duration (80 versus 14 hours; P<0.001) and intensive care unit stay (216 versus 68 hours; P<0.001). Younger age at surgery, higher surgical complexity, lower oxygen saturation, and major medical illness were independent risk factors for infection. The overall standardized infection ratio was 0.65 (95% confidence interval, 0.58-0.73) in 2011 and 0.59 (95% confidence interval, 0.54-0.64) in 2012, compared with that in 2010. CONCLUSIONS: Postoperative infections contribute to mortality and morbidity after congenital heart surgery. Younger, more complex patients are at particular risk. Quality improvement targeted at infection risk may reduce morbidity and mortality in the developing world.

Barriers to the use of face protection for standard precautions by health care providers.

Health care providers sometimes choose not to use face protection even when indicated as part of standard precautions. We performed a survey of pediatric health care providers to determine barriers to the routine use of face protection. Lack of availability at the point of care and a perceived lack of need were the most commonly cited issues. Continuing education is needed regarding situations in which face protection is indicated for standard precautions.

Interventional study to evaluate the impact of an alcohol-based hand gel in improving hand hygiene compliance.

OBJECTIVE: To evaluate the effects of the introduction of an alcohol-based hand gel and multifaceted quality improvement (QI) interventions on hand hygiene (HH) compliance. DESIGN: Interventional, randomized cohort study with four study phases (baseline; limited intervention in two units; full intervention in three units; washout phase), performed in three intensive care units at a pediatric referral hospital. METHODS: During 724 thirty-minute daytime monitoring sessions, a nonidentified observer witnessed 12,216 opportunities for HH and recorded compliance. INTERVENTIONS: Introduction of an alcohol-based hand gel; multifaceted QI interventions (educational program, opinion leaders, performance feedback). RESULTS: Baseline compliance decreased after the first 2 weeks of observation from 42.5% to 28.2% (presumably because of waning of a Hawthorne effect), further decreased to 23.3% in the limited intervention phase and increased to 35.1% after the introduction of a hand gel with QI support in all three units (P < 0.001). The rise in compliance persisted in the last phase (compliance, 37.2%); however, a gradual decline was observed during the final weeks. Except for the limited intervention phase, compliance achieved through standard handwashing and glove use remained stable around 20 and 10%, respectively, whereas compliance achieved through gel use increased to 8% (P < 0.001). After adjusting for confounding, implementation of the hand gel with QI support remained significantly associated with compliance (odds ratio, 1.6; 95% confidence interval, 1.4 to 1.8). In a final survey completed by 62 staff members, satisfaction with the hand gel was modest (45%). CONCLUSIONS: We noted a statistically significant, modest improvement in compliance after introduction of an alcohol-based hand gel with multifaceted QI support. When appropriately implemented, alcohol-based HH may be effective in improving compliance.

An outbreak of Pseudomonas aeruginosa pneumonia and bloodstream infection associated with intermittent otitis externa in a healthcare worker.

OBJECTIVES: To investigate an outbreak of Pseudomonas aeruginosa pneumonia and bloodstream infection among four neonates, determine risk factors for infection, and implement preventive strategies. DESIGN: Retrospective case finding; prospective surveillance cultures of patients, personnel, and environmental sites; molecular typing by pulsed-field gel electrophoresis; and a matched case-control study. PATIENTS AND SETTING: Neonates in the level-III neonatal intensive care unit of a tertiary-care pediatric institution. INTERVENTIONS: Cohorting of patients with positive results for P. aeruginosa, work restrictions for staff with positive results, implementation of an alcohol-based hand product, review of infection control policies and procedures, and closure of the unit until completion of the investigation. RESULTS: Seven (4%) of 190 environmental cultures and 5 (3%) of 178 cultures of individual healthcare workers' hands grew P. aeruginosa. All four outbreak isolates and one previous bloodstream isolate were genotypically identical, as were the P. aeruginosa isolates from the hands and external auditory canal of a healthcare worker with intermittent otitis externa. Four of 5 case-patients versus 5 of 15 matched control-patients had been cared for by this healthcare worker (P = .05). The healthcare worker was treated and no further cases occurred. CONCLUSIONS: These findings suggest that a healthcare worker with intermittent otitis externa may have caused this cluster of fatal P. aeruginosa infections, adding the external ear to the list of colonized body sites that may serve as a source of potentially pathogenic organisms.

Impact of needleless connector change frequency on central line-associated bloodstream infection rate.

BACKGROUND: Bloodstream infection is the most common pediatric health care-associated infection and is strongly associated with catheter use. These infections greatly increase the cost of hospital stay. METHODS: To assess the association between needleless connector (NC) change frequency and central line-associated bloodstream infection (CLABSI) rate, we modeled monthly pediatric stem cell transplant (SCT) CLABSI rate in 3 periods: baseline period during which NC were changed every 96 hours regardless of infusate (period 1); trial period in which NC were changed every 24 hours with blood or lipid infusions (period 2); and a return to NC change every 96 hours regardless of infusate (period 3). Data on potential confounders were collected retrospectively. Autocorrelated segmented regression models were used to compare SCT CLABSI rates in each period, adjusting for potential confounders. CLABSI rates were also assessed for a nonequivalent control group (oncology unit) in which NC were changed every 24 hours with blood or lipid use in periods 2 and 3. RESULTS: SCT CLABSI rates were 0.41, 3.56, and 0.03 per 1,000 central line-days in periods 1, 2, and 3, respectively. In multivariable analysis, the CLABSI rate was significantly higher in period 2 compared with both period 1 (P = .01) and period 3 (P = .003). In contrast, CLABSI rates on the oncology unit were not significantly different among periods. CONCLUSION: In pediatric SCT patients, changing needleless connectors every 24 hours when blood or lipids are infused is associated with increased CLABSI rates. National recommendations regarding NC change frequency should be clarified.

Central line-associated bloodstream infections in neonates with gastrointestinal conditions: developing a candidate definition for mucosal barrier injury bloodstream infections.

OBJECTIVE: To develop a candidate definition for central line-associated bloodstream infection (CLABSI) in neonates with presumed mucosal barrier injury due to gastrointestinal (MBI-GI) conditions and to evaluate epidemiology and microbiology of MBI-GI CLABSI in infants. DESIGN: Multicenter retrospective cohort study. SETTING: Neonatal intensive care units from 14 US children's hospitals and pediatric facilities. METHODS: A multidisciplinary focus group developed a candidate MBI-GI CLABSI definition based on presence of an MBI-GI condition, parenteral nutrition (PN) exposure, and an eligible enteric organism. CLABSI surveillance data from participating hospitals were supplemented by chart review to identify MBI-GI conditions and PN exposure. RESULTS: During 2009-2012, 410 CLABSIs occurred in 376 infants. MBI-GI conditions and PN exposure occurred in 149 (40%) and 324 (86%) of these 376 neonates, respectively. The distribution of pathogens was similar among neonates with versus without MBI-GI conditions and PN exposure. Fifty-nine (16%) of the 376 initial CLABSI episodes met the candidate MBI-GI CLABSI definition. Subsequent versus initial CLABSIs were more likely to be caused by an enteric organism (22 of 34 [65%] vs 151 of 376 [40%]; P = .009) and to meet the candidate MBI-GI CLABSI definition (19 of 34 [56%] vs 59 of 376 [16%]; P < .01). CONCLUSIONS: While MBI-GI conditions and PN exposure were common, only 16% of initial CLABSIs met the candidate definition of MBI-GI CLABSI. The high proportion of MBI-GI CLABSIs among subsequent infections suggests that infants with MBI-GI CLABSI should be a population targeted for further surveillance and interventional research.

Improving stethoscope disinfection at a children's hospital.

OBJECTIVE: Stethoscopes are contaminated with pathogenic bacteria and pose a risk for transmission of infections, but few clinicians disinfect their stethoscope after every use. We sought to improve stethoscope disinfection rates among pediatric healthcare providers by providing access to disinfection materials and visual reminders to disinfect stethoscopes. DESIGN: Prospective intervention study. SETTING: Inpatient units and emergency department of a major pediatric hospital. PARTICIPANTS: Physicians and nurses with high anticipated stethoscope use. METHODS: Baskets filled with alcohol prep pads and a sticker reminding providers to regularly disinfect stethoscopes were installed outside of patient rooms. Healthcare providers' stethoscope disinfection behaviors were directly observed before and after the intervention. Multivariable logistic regression models were created to identify independent predictors of stethoscope disinfection. RESULTS: Two hundred twenty-six observations were made in the preintervention period and 261 in the postintervention period (83% were of physicians). Stethoscope disinfection compliance increased significantly from a baseline of 34% to 59% postintervention (P < .001). In adjusted analyses, the postintervention period was associated with improved disinfection among both physicians (odds ratio [OR], 2.3 [95% confidence interval (CI), 1.4-3.5]) and nurses (OR, 14.3 [95% CI, 4.6-44.6]). Additional factors independently associated with disinfection included subspecialty unit (vs general pediatrics; OR, 0.5 [95% CI, 0.3-0.8]) and contact precautions (OR, 2.3 [95% CI, 1.2-4.1]). CONCLUSIONS: Providing stethoscope disinfection supplies and visible reminders outside of patient rooms significantly increased stethoscope disinfection rates among physicians and nurses at a children's hospital. This simple intervention could be replicated at other healthcare facilities. Future research should assess the impact on patient infections.

Beyond the bundle: a survey of central line-associated bloodstream infection prevention practices used in US and Canadian pediatric hospitals.

We surveyed US and Canadian pediatric hospitals about their use of central line-associated bloodstream infection (CLABSI) prevention strategies beyond typical insertion and maintenance bundles. We found wide variation in supplemental strategies across hospitals and in their penetration within hospitals. Future studies should assess specific adjunctive prevention strategies and CLABSI rates.

Infection prevention in anesthesia practice: a tool to assess risk and compliance.

Transmission of bacterial and viral infections to patients from improper anesthesia infection prevention and control practices continues to be reported. "Recommendations for Infection Control for the Practice of Anesthesiology" were recently revised. The process used to develop an anesthesia infection prevention assessment tool is described. The tool is intended to encourage collaboration between infection preventionists and anesthesia providers in an effort to assess infection prevention and control practices in various health care anesthesia settings.

Moving CLABSI prevention beyond the intensive care unit: risk factors in pediatric oncology patients.

BACKGROUND AND OBJECTIVE: 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. DESIGN: Retrospective case-control study. SETTING: Oncology and stem cell transplant units of a freestanding, 396-bed quaternary care pediatric hospital. PARTICIPANTS: Case subjects ([Formula: see text]) were patients with a diagnosis of malignancy and/or stem cell transplant recipients with CLABSI occurring during admission. Controls ([Formula: see text]) were identified using risk set sampling of hospitalizations among patients with a CVC, matched on date of admission. METHODS: Multivariate conditional logistic regression was used to identify independent predictors of CLABSI. RESULTS: 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]; [Formula: see text]) and CVC placement within the previous month (<1 week vs ≥1 month: OR, 11.71 [95% CI, 1.98-69.20]; [Formula: see text]; ≥1 week and <1 month vs ≥1 month: OR, 7.37 [95% CI, 1.85-29.36]; [Formula: see text]). CONCLUSIONS: 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.

Epidemiology and risk factors for Clostridium difficile infection in children.

BACKGROUND: Pediatric Clostridium difficile infection (CDI)-related hospitalizations are increasing. We sought to describe the epidemiology of pediatric CDI at a quaternary care hospital. METHODS: Nested case-control study within a cohort of children <18 years tested for C. difficile between January and August 2008. The study included patients who were ≥ 1 year with a positive test and diarrhea; those without diarrhea (ie, presumed colonization) were excluded. Two unmatched controls per case were randomly selected from patients ≥ 1 year with a negative test. Potential predictors of CDI included age, gender, comorbidities, prior hospitalization, receipt of C. difficile-active antibiotics in the prior 24 hours, and recent (≤ 4 weeks) exposure to antibiotics or acid-blocking medications. Multivariate logistic regression models were created to identify independent predictors of CDI. RESULTS: Of 1891 tests performed, 263 (14%) were positive in 181 children. Ninety-five patients ≥ 1 year with CDI were compared with 238 controls. In multivariate analyses, predictors of CDI included solid organ transplant (odds ratio [OR], 8.09; 95% confidence interval [CI], 2.10-31.12), lack of prior hospitalization (OR, 8.43; 95% CI, 4.39-16.20), presence of gastrostomy or jejunostomy (G or J) tube (OR, 3.32; 95% CI 1.71-6.42), and receipt of fluoroquinolones (OR, 17.04; 95% CI, 5.86-49.54) or nonquinolone antibiotics (OR, 2.23; 95% CI, 1.18-4.20) in the past 4 weeks. Receipt of C. difficile-active antibiotics within 24 hours before testing was associated with a lower odds of CDI (OR, 0.22; 95% CI, 0.09-0.58). CONCLUSIONS: Recent antibiotic exposure and certain comorbid conditions (solid organ transplant, presence of a gastrostomy or jejunostomy tube) were associated with CDI. Diagnostic testing has less utility in patients being treated with C. difficile-active antibiotics.

Parallel bacterial evolution within multiple patients identifies candidate pathogenicity genes.

Bacterial pathogens evolve during the infection of their human host(1-8), but separating adaptive and neutral mutations remains challenging(9-11). Here we identify bacterial genes under adaptive evolution by tracking recurrent patterns of mutations in the same pathogenic strain during the infection of multiple individuals. We conducted a retrospective study of a Burkholderia dolosa outbreak among subjects with cystic fibrosis, sequencing the genomes of 112 isolates collected from 14 individuals over 16 years. We find that 17 bacterial genes acquired nonsynonymous mutations in multiple individuals, which indicates parallel adaptive evolution. Mutations in these genes affect important pathogenic phenotypes, including antibiotic resistance and bacterial membrane composition and implicate oxygen-dependent regulation as paramount in lung infections. Several genes have not previously been implicated in pathogenesis and may represent new therapeutic targets. The identification of parallel molecular evolution as a pathogen spreads among multiple individuals points to the key selection forces it experiences within human hosts.

Risk factors for central line-associated bloodstream infection in pediatric intensive care units.

OBJECTIVE: We sought to identify risk factors for central line-associated bloodstream infection (CLABSI) to describe children who might benefit from adjunctive interventions. DESIGN: Case-control study of children admitted to the medical-surgical intensive care unit (ICU) or cardiac ICU from January 1, 2004, through December 31, 2007. SETTING: Children's Hospital Boston is a freestanding, 396-bed quaternary care pediatric hospital with a 29-bed medical-surgical ICU and a 24-bed cardiac ICU. PATIENTS: Case patients were patients with CLABSI who were identified by means of prospective surveillance. Control subjects were patients with a central venous catheter who were matched by ICU admission date. METHODS: Multivariate conditional logistic regression models were used to identify independent risk factors for CLABSI and to derive and to validate a prediction rule. RESULTS: Two hundred three case patients were matched with 406 control subjects. Independent predictors of CLABSI included duration of ICU central access (odds ratio [OR] for 15 or more days, 18.41 [95% confidence interval {CI}, 4.10-82.56]; P < .001), central venous catheter placement in the ICU (OR for 2 or more ICU-placed catheters, 8.63 [95% CI, 2.63-28.38]; P = .001), nonoperative cardiovascular disease (OR, 7.44 [95% CI, 2.13-25.98]; P = .012), presence of gastrostomy tube (OR, 3.48 [95% CI, 1.55-7.79]; P = .003), receipt of parenteral nutrition (OR, 3.12 [95% CI, 1.55-6.32]; P = .002), and receipt of blood transfusion (OR, 2.55 [95% CI, 1.21-5.36]; P = .014). By use of risk factors known before central venous catheter placement, our model predicted CLABSI with a positive predictive value of 54% and a negative predictive value of 79%. CONCLUSIONS: Duration of central access, receipt of parenteral nutrition, and receipt of blood transfusion were confirmed as risk factors for CLABSI among children in the ICU. Newly identified risk factors include presence of gastrostomy tube, nonoperative cardiovascular disease, and ICU placement of central venous catheter. Children with these risk factors may be candidates for adjunctive interventions for CLABSI prevention.

Risk factors for surgical site infection after cardiac surgery in children.

BACKGROUND: We sought to identify risk factors for surgical site infections (SSI) in children undergoing cardiac surgery. METHODS: A matched case-control study was conducted in the Children's Hospital Boston Cardiovascular Program. Surgical site infections were identified for 3 years (2004 to 2006). We identified two randomly selected control patients who underwent cardiac surgery within 7 days of each index case. Univariate and multivariate conditional logistic regression analyses were used to identify risk factors for SSI. In a secondary analysis, risk factors for organ space SSI (mediastinitis) were sought. Secondary analyses were also conducted using only those variables known preoperatively. RESULTS: Seventy-two SSI and 144 controls were included. Independent risk factors for any type of SSI were age younger than 1 year (adjusted odds ratio, 2.28; 95% confidence interval, 1.18 to 4.39) and duration of cardiopulmonary bypass greater than 105 minutes (adjusted odds ratio, 1.92; 95% confidence interval, 1.02 to 3.62). Independent risk factors for organ space SSI were aortic cross-clamp time greater than 85 minutes (adjusted odds ratio, 5.61; 95% confidence interval, 1.06 to 29.67) and postoperative exposure to at least three separate red blood cell transfusions (adjusted odds ratio, 7.87; 95% confidence interval, 1.63 to 37.92). When only those potential risk factors known preoperatively were considered, age younger than 1 year independently predicted the subsequent development of any type of SSI, and preoperative hospitalization independently predicted the subsequent development of organ space SSI. CONCLUSIONS: Younger patients undergoing longer surgical procedures and those requiring more postoperative blood transfusions are at greatest risk for SSI. Additional preventive strategies, including restrictive blood transfusion policies, warrant further investigation.