To determine the costs of the interventions aimed at controlling the 4-month outbreak and to determine the attributable length of stay (LOS) associated with infection and colonization with extended-spectrum beta-lactamase-producing Klebsiella pneumoniae.

A retrospective cost analysis was conducted from the hospital perspective. A micro-costing approach was employed. The LOS of four groups of hospitalized patients were compared with each other. National Perinatal Information Center criteria were used to stratify infants for severity of risk. The LOS of each group was compared with that of a national sample of similarly stratified infants.

A level III-IV, 45-bed neonatal intensive care unit.

Infant groups were infected (n = 8), colonized (n = 14), concurrent cohort (n = 54), and prior cohort (n = 486).

The cost of the outbreak totaled $341,751. The largest proportion of costs was related to healthcare worker time providing direct patient care (2,489 hours at a cost of $146,331). Infected and colonized neonates had longer LOS than either the concurrent cohort or the prior cohort (P < .001). Compared with the national sample, infected infants had a 48.5-day longer mean LOS (95% confidence interval [CI95], 1.7 to 95.2), whereas the prior cohort's mean LOS was 6 days shorter (CI95, -9.4 to -2.9).

This study increases the understanding of the burden of these multidrug-resistant organisms. Further research is needed to estimate the societal costs of these infections and the cost-effectiveness of preventive interventions.

To quantify the economic burden of in-hospital surgical site infections (SSIs) at a European university hospital.

Matched case-control study nested in a prospective observational cohort study.

Basel University Hospital in Switzerland, where an average of 28,000 surgical procedures are performed per year.

All in-hospital occurrences of SSI associated with surgeries performed between January 1, 2000, and December 31, 2001, by the visceral, vascular, and traumatology divisions at Basel University Hospital were prospectively recorded. Each case patient was matched to a control patient by age, procedure code, and National Nosocomial Infection Surveillance System risk index. The case-control pairs were analyzed for differences in cost of hospital care and in provision of specialized care.

A total of 6,283 procedures were performed:187 SSIs were detected in inpatients, 168 of whom were successfully matched with a control patient. For case patients, the mean additional hospital cost was SwF19,638 (95% confidence interval [CI], SwF8,492–SwF30,784); the mean additional postoperative length of hospital stay was 16.8 days (95% CI, 13–20.6 days); and the mean additional in-hospital duration of antibiotic therapy was 7.4 days (95% CI, 5.1–9.6 days). Differences were primarily attributable to organ space SSIs (n = 76).

Ina European university hospital setting, SSIs are costly and constitute a heavy and potentially preventable burden on both patients and healthcare providers.

In September 2006, the Centers for Disease Control and Prevention was notified of cases of gram-negative bloodstream infection (BSI) occurring among outpatients who received an intravenous formulation of the prostanoid treprostinil. An investigation was conducted to determine rates of prostanoid-associated BSI in this patient population and possible risk factors for infection.

We performed a retrospective cohort study of patients who had received intravenous formulations of at least 1 of the 2 approved prostanoids (epoprostenol and treprostinil) from January 1, 2004, through late 2006. Chart reviews were conducted at 2 large centers for pulmonary arterial hypertension, and a survey of infection control practices was conducted at 1 center.

A total of 224 patients were given intravenous prostanoid treatment, corresponding to 146,093 treatment-days during the study period. Overall, there were 0.55 cases of BSI and 0.18 cases of BSI due to gram-negative organisms per 1,000 treatment-days. BSI rates were higher for patients who received intravenous treprostinil than for patients who received intravenous epoprostenol (1.13 vs. 0.42 BSIs per 1,000 treatment-days; P < .001), as were rates of BSI due to gram-negative organisms (0.81 vs. 0.04 BSIs per 1,000 treatment-days; P < .001). Adjusted hazard ratios for all BSIs and for BSIs due to gram-negative organisms were higher among patients given treatment with intravenous treprostinil. The survey identified no significant differences in medication-related infection control practices.

At 2 centers, BSI due to gram-negative pathogens was more common than previously reported and was more frequent among patients given treatment with intravenous treprostinil than among patients given treatment with intravenous epoprostenol. Whether similar results would be found at other centers for pulmonary arterial hypertension warrants further investigation. This investigation underscores the importance of surveillance and evaluation of healthcare-related adverse events in patients given treatment primarily as outpatients.

To determine whether introduction of a needleless mechanical valve device (NMVD) at a long-term acute care hospital was associated with an increased frequency of catheter-related bloodstream infection (BSI).

For patients with a central venous catheter in place, the catheter-related BSI rate during the 24-month period before introduction of the NMVD, a period in which a needleless split-septum device (NSSD) was being used (hereafter, the NSSD period), was compared with the catheter-related BSI rate during the 24-month period after introduction of the NMVD (hereafter, the NMVD period). The microbiological characteristics of catheter-related BSIs during each period were also compared. Comparisons and calculations of relative risks (RRs) with 95% confidence intervals (CIs) were performed using χ2 analysis.

Eighty-six catheter-related BSIs (3.86 infections per 1,000 catheter-days) occurred during the study period. The rate of catheter-related BSI during the NMVD period was significantly higher than that during the NSSD period (5.95 vs 1.79 infections per 1,000 catheter-days; RR, 3.32 [95% CI, 2.88–3.83]; P < .001). A significantly greater percentage of catheter-related BSIs during the NMVD period were caused by gram-negative organisms, compared with the percentage recorded during the NSSD period (39.5% vs 8%; P = .007). Among catheter-related BSIs due to gram-positive organisms, the percentage caused by enterococci was significantly greater during the NMVD period, compared with the NSSD period (54.8% vs 13.6%; P = .004). The catheter-related BSI rate remained high during the NMVD period despite several educational sessions regarding proper use of the NMVD.

An increased catheter-related BSI rate was temporally associated with use of a NMVD at the study hospital, despite several educational sessions regarding proper NMVD use. The current design of the NMVD may be unsafe for use in certain patient populations.

Before-after prospective surveillance study to assess the efficacy of the International Nosocomial Infection Control Consortium (INICC) multidimensional infection control program to reduce the rate of occurrence of ventilator-associated pneumonia (VAP).

Neonatal intensive care units (NICUs) of INICC member hospitals from 15 cities in the following 10 developing countries: Argentina, Colombia, El Salvador, India, Mexico, Morocco, Peru, Philippines, Tunisia, and Turkey.

NICU inpatients.

VAP rates were determined during a first period of active surveillance without the implementation of the multidimensional approach (phase 1) to be then compared with VAP rates after implementation of the INICC multidimensional infection control program (phase 2), which included the following practices: a bundle of infection control interventions, education, outcome surveillance, process surveillance, feedback on VAP rates, and performance feedback on infection control practices. This study was conducted by infection control professionals who applied National Health Safety Network (NHSN) definitions for healthcare-associated infections and INICC surveillance methodology.

During phase 1, we recorded 3,153 mechanical ventilation (MV)–days, and during phase 2, after the implementation of the bundle of interventions, we recorded 15,981 MV-days. The VAP rate was 17.8 cases per 1,000 MV-days during phase 1 and 12.0 cases per 1,000 MV-days during phase 2 (relative risk, 0.67 [95% confidence interval, 0.50–0.91]; P = .001 ), indicating a 33% reduction in VAP rate.

Our results demonstrate that an implementation of the INICC multidimensional infection control program was associated with a significant reduction in VAP rate in NICUs in developing countries.

Coagulase-negative staphylococci (CNS) are the major cause of nosocomial bloodstream infection. Emergence of vancomycin resistance among CNS is a serious public health concern, because CNS usually are multidrug-resistant, and glycopeptide antibiotics, among which only vancomycin is available in the United States, are the only remaining effective therapy. In this report, we describe the first bloodstream infection in the United States associated with a Staphylococcus epidermidis strain with decreased susceptibility to vancomycin.

We reviewed the hospital's microbiology records for all CNS strains, reviewed the patient's medical and laboratory records, and obtained all available CNS isolates with decreased susceptibility to vancomycin. Blood cultures were processed and CNS isolates identified by using standard methods; antimicrobial susceptibility was determined by using minimum inhibitory concentration (MIC) and disk-diffusion methods. Nares cultures were obtained from exposed healthcare workers (HCWs) to identify possible colonization by CNS with decreased susceptibility to vancomycin.

The bloodstream infection by an S epidermidis strain with decreased susceptibility to vancomycin occurred in a 49-year-old woman with carcinoma. She had two blood cultures positive for CNS; both isolates were S epidermidis. Although susceptible to vancomycin by the disk-diffusion method (16-17 mm), the isolates were intermediate by MIC (8-6 μg/mL). The patient had received an extended course of vancomycin therapy; she died of her underlying disease. No HCW was colonized by CNS with decreased susceptibility to vancomycin.

This is the first report in the United States of bloodstream infection due to S epidermidis with decreased susceptibility to vancomycin. Contact precautions likely played a role in preventing nosocomial transmission of this strain, and disk-diffusion methods may be inadequate to detect CNS with decreased susceptibility to vancomycin.

To determine the typical microbial bioburden (overall bacterial and multidrug-resistant organisms [MDROs]) on high-touch healthcare environmental surfaces after routine or terminal cleaning.

Prospective 2.5-year microbiological survey of large surface areas (>1,000 cm2).

MDRO contact-precaution rooms from 9 acute-care hospitals and 2 long-term care facilities in 4 states.

Samples from 166 rooms (113 routine cleaned and 53 terminal cleaned rooms).

Using a standard sponge-wipe sampling protocol, 2 composite samples were collected from each room; a third sample was collected from each Clostridium difficile room. Composite 1 included the TV remote, telephone, call button, and bed rails. Composite 2 included the room door handle, IV pole, and overbed table. Composite 3 included toileting surfaces. Total bacteria and MDROs (ie, methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci [VRE], Acinetobacter baumannii, Klebsiella pneumoniae, and C. difficile) were quantified, confirmed, and tested for drug resistance.

The mean microbial bioburden and range from routine cleaned room composites were higher (2,700 colony-forming units [CFU]/100 cm2; ≤1–130,000 CFU/100 cm2) than from terminal cleaned room composites (353 CFU/100 cm2; ≤1–4,300 CFU/100 cm2). MDROs were recovered from 34% of routine cleaned room composites (range ≤1–13,000 CFU/100 cm2) and 17% of terminal cleaned room composites (≤1–524 CFU/100 cm2). MDROs were recovered from 40% of rooms; VRE was the most common (19%).

This multicenter bioburden summary provides a first step to determining microbial bioburden on healthcare surfaces, which may help provide a basis for developing standards to evaluate cleaning and disinfection as well as a framework for studies using an evidentiary hierarchy for environmental infection control.

Infect Control Hosp Epidemiol 2016;1426–1432

To determine a potential source of MRSA colonization and infection among preterm infants in a neonatal intensive care unit (NICU) using molecular analysis of breast milk samples.

Case report, outbreak investigation.

Preterm triplets were delivered at 26 weeks' gestation via cesarean section when routine active surveillance for MRSA was performed for all infants in a NICU. Surveillance consisted of swabbing the throat, nose, and umbilicus (TNU) weekly. Although infants A and B initially had negative TNU swabs, repeat cultures were positive for MRSA on day of life (DOL) 10 and DOL 18, respectively. Surveillance and clinical cultures for infant C were negative. Infant A developed sepsis, and multiple blood cultures were positive for MRSA beginning on DOL 14. Infant B developed conjunctivitis and a conjunctival exudate culture was positive for MRSA on DOL 70. Both infants were fed breast milk via nasogastric tube. Cultures of breast milk samples for infants A and B dated prior to either infant's first positive surveillance culture were positive for MRSA. All MRSA isolates had identical results on antibiotic susceptibility testing. PFGE demonstrated identical banding patterns for the MRSA isolates from the blood culture of infant A, breast milk for infants A and B, and a surveillance swab from infant B. At no time did the mother develop evidence of mastitis or other local breast infection.

MRSA can be passed from mother to preterm infant through contaminated breast milk, even in the absence of maternal infection. Colonization and clinical disease can result.

To determine whether transfer from a long-term care facility (LTCF) is a risk factor for colonization with Klebsiella pneumoniae carbapenemase (KPC)–producing Enterobacteriaceae upon acute care hospital admission.

Microbiologic survey and nested case-control study.

Four hospitals in a metropolitan area (Chicago) with an early KPC epidemic.

Hospitalized adults.

Patients transferred from LTCFs were matched 1 : 1 to patients admitted from the community by age (± 10 years), admitting clinical service, and admission date (± 2 weeks). Rectal swab specimens were collected within 3 days after admission and tested for KPC-producing Enterobacteriaceae. Demographic and clinical information was extracted from medical records.

One hundred eighty patients from LTCFs were matched to 180 community patients. KPC-producing Enterobacteriaceae colonization was detected in 15 (8.3%) of the LTCF patients and 0 (0%) of the community patients (P<.001). Prevalence of carriage differed by LTCF subtype: 2 of 135 (1.5%) patients from skilled nursing facilities without ventilator care (SNFs) were colonized upon admission, compared to 9 of 33 (27.3%) patients from skilled nursing facilities with ventilator care (VSNFs) and 4 of 12 (33.3%) patients from long-term acute care hospitals (LTACHs; P<.001). In a multivariable logistic regression model adjusted for a propensity score that predicted LTCF subtype, patients admitted from VSNFs or LTACHs had 7.0-fold greater odds of colonization (ie, odds ratio; 95% confidence interval, 1.3–42; P = .022) with KPC-producing Enterobacteriaceae than patients from an SNF.

Patients admitted to acute care hospitals from high-acuity LTCFs (ie, VSNFs and LTACHs) were more likely to be colonized with KPC-producing Enterobacteriaceae than were patients admitted from the community. Identification of healthcare facilities with a high prevalence of colonized patients presents an opportunity for focused interventions that may aid regional control efforts.

To describe the control of multidrug-resistant Acinetobacter baumannii-calcoaceticus (MDRABC) colonization and infection in an intensive care unit (ICU).

An 18-bed ICU in a large tertiary care teaching hospital in London.

After recognition of the outbreak, a range of infection control measures were introduced over several months that were primarily aimed at reducing environmental contamination with the outbreak strain. Strategies included use of a closed tracheal suction system for all patients receiving mechanical ventilation, use of nebulized colistin for patients with evidence of mild to moderate ventilator-associated pneumonia, improved availability of alcohol for hand decontamination, and clearer designation of responsibilities and strategies for cleaning equipment and the environment in the proximity of patients colonized or infected with MDRABC.

The outbreak lasted from June 2001 through November 2002 and involved 136 new cases of MDRABC infection or colonization. The number of newly diagnosed cases per month reached a maximum of 15 in February 2002, and the number of new cases slowly decreased over the next 9 months.

This outbreak was controlled by emphasizing the control of environmental reservoirs and did not require recourse to ward closure or placement of affected patients in isolation.

To determine the impact of the screening test, nursing workload, handwashing rates, and dependence of handwashing on risk level of patient visit on methicillin-resistant Staphylococcus aureus (MRSA) transmission among hospitalized patients.

General medical ward.

Monte Carlo simulation was used to model MRSA transmission (median rate per 1,000 patient-days). Visits by healthcare workers (HCWs) to patients were simulated, and MRSA was assumed to be transmitted among patients via HCWs.

The transmission rate was reduced from 0.89 to 0.56 by the combination of increasing the sensitivity of the screening test from 80% to 99% and being able to report results in 1 day instead of 4 days. Reducing the patient-to-nurse ratio from 4.3 in the day and 6.8 at night to 3.8 and 5.7, respectively, reduced the number of nosocomial infections from 0.89 to 0.85; reducing the ratio to 1 and 1, respectively, further reduced the number of nosocomial infections to 0.32. Increases in handwashing rates by 0%, 10%, and 20% for high-risk visits yielded reductions in nosocomial infections similar to those yielded by increases in handwashing rates for all visits (0.89, 0.36, and 0.24, respectively). Screening all patients for MRSA at admission reduced the transmission rate to 0.81 per 1,000 patient-days from 1.37 if no patients were screened.

Within the ranges of parameters studied, the most effective strategies for reducing the rate of MRSA transmission were increasing the handwashing rates for visits involving contact with skin or bodily fluid and screening patients for MRSA at admission. (Infect Control Hosp Epidemiol 2005;26:607- 615)

Economic evaluation has become increasingly important in healthcare and infection control. This study evaluated the impact of nosocomial infections on cost of illness and length of stay (LOS) in intensive care units (ICUs).

A retrospective cohort study.

Medical, surgical, and mixed medical and surgical ICUs in a tertiary-care referral medical center.

Patients admitted to adult ICUs between October 2001 and June 2002 were eligible for the study.

Estimates of the cost and LOS for patients who acquired a nosocomial infection were computed using a stratified analysis and regression approach.

During the study period, 778 patients were admitted to the ICUs. Total costs for patients with and without nosocomial infections (median cost, $10,354 and $3,985, respectively) were significantly different (P < .05). The costs stratified by infection site (median differences from $4,687 to $7,365) and primary diagnosis (median differences from $5,585 to $16,507) were also significantly different (P < .05) except for surgical-site infection. After covariates were adjusted for in the multiple linear regression, nosocomial infection increased the total costs by $3,306 per patient and increased the LOS by 18.2 days per patient (P < .001). Each additional day spent in the ICU increased the cost per patient by $353 (P < .001).

Nosocomial infections are associated with increased cost of illness and LOS. Prevention of nosocomial infections should reduce direct costs and decrease the LOS.

To describe the control of multidrug-resistant Acinetobacter baumannii-calcoaceticus (MDRABC) colonization and infection in an intensive care unit (ICU).

An 18-bed ICU in a large tertiary care teaching hospital in London.

After recognition of the outbreak, a range of infection control measures were introduced over several months that were primarily aimed at reducing environmental contamination with the outbreak strain. Strategies included use of a closed tracheal suction system for all patients receiving mechanical ventilation, use of nebulized colistin for patients with evidence of mild to moderate ventilator-associated pneumonia, improved availability of alcohol for hand decontamination, and clearer designation of responsibilities and strategies for cleaning equipment and the environment in the proximity of patients colonized or infected with MDRABC.

The outbreak lasted from June 2001 through November 2002 and involved 136 new cases of MDRABC infection or colonization. The number of newly diagnosed cases per month reached a maximum of 15 in February 2002, and the number of new cases slowly decreased over the next 9 months.

This outbreak was controlled by emphasizing the control of environmental reservoirs and did not require recourse to ward closure or placement of affected patients in isolation.

Recent outbreaks of Clostridium difficile infection (CDI) have been difficult to control, and data indicate that the importance of different sources of transmission may have changed. Our objectives were to evaluate the contributions of asymptomatic and symptomatic C. difficile carriers to new colonizations and to determine the most important epidemiological factors influencing C. difficile transmission.

Retrospective cohort study of all patients admitted to medical wards at a large tertiary care hospital in the United States in the calendar year 2008.

Data from six medical wards and published literature were used to develop a compartmental model of C. difficile transmission. Patients could be in one of five transition states in the model: resistant to colonization (R), susceptible to colonization (S), asymptomatically colonized without protection against CDI (C-), asymptomatically colonized with protection against CDI (C+), and diseased (ie, with CDI; D).

The contributions of C-, C+, and D patients to new colonizations were similar. The simulated basic reproduction number ranged from 0.55 to 1.99, with a median of 1.04. These values suggest that transmission within the ward alone from patients with CDI cannot sustain new C. difficile colonizations and therefore that the admission of colonized patients plays an important role in sustaining transmission in the ward. The epidemiological parameters that ranked as the most influential were the proportion of admitted C- patients and the transmission coefficient for asymptomatic carriers.

Our study underscores the need to further evaluate the role of asymptomatically colonized patients in C. difficile transmission in healthcare settings.