To evaluate the effectiveness of the oral application of a 0.12% solution of Chlorhexidine for prevention of respiratory tract infections among intensive care unit (ICU) patients.

The study design was a double-blind, randomized, placebo-controlled trial.

The study was performed in an ICU in a tertiary care hospital at a public university.

Study participants comprised 194 patients admitted to the ICU with a prospective length of stay greater than 48 hours, randomized into 2 groups: those who received Chlorhexidine (n = 98) and those who received a placebo (n = 96).

Oral rinses with Chlorhexidine or a placebo were performed 3 times a day throughout the duration of the patient's stay in the ICU. Clinical data were collected prospectively.

Both groups displayed similar baseline clinical features. The overall incidence of respiratory tract infections (RR, 1.0 [95% confidence interval [CI], 0.63-1.60]) and the rates of ventilator-associated pneumonia per 1,000 ventilator-days were similar in both experimental and control groups (22.6 vs 22.3; P = .95). Respiratory tract infection-free survival time (7.8 vs 6.9 days; P = .61), duration of mechanical ventilation (11.1 vs 11.0 days; P = .61), and length of stay (9.7 vs 10.4 days; P = .67) did not differ between the Chlorhexidine and placebo groups. However, patients in the Chlorhexidine group exhibited a larger interval between ICU admission and onset of the first respiratory tract infection (11.3 vs 7.6 days; P = .05). The chances of surviving the ICU stay were similar (RR, 1.08 [95% CI, 0.72-1.63]).

Oral application of a 0.12% solution of Chlorhexidine does not prevent respiratory tract infections among ICU patients, although it may retard their onset.

Although prior authorization and prospective audit with feedback are both effective antimicrobial stewardship program (ASP) strategies, the relative impact of these approaches remains unclear. We compared these core ASP strategies at an academic medical center.

Quasi-experimental study.

We compared antimicrobial use during the 24 months before and after implementation of an ASP strategy change. The ASP used prior authorization alone during the preintervention period, June 2007 through May 2009. In June 2009, many antimicrobials were unrestricted and prospective audit was implemented for cefepime, piperacillin/tazobactam, and vancomycin, marking the start of the postintervention period, July 2009 through June 2011. All adult inpatients who received more than or equal to 1 dose of an antimicrobial were included. The primary end point was antimicrobial consumption in days of therapy per 1,000 patient-days (DOT/1,000-PD). Secondary end points included length of stay (LOS).

In total, 55,336 patients were included (29,660 preintervention and 25,676 postintervention). During the preintervention period, both total systemic antimicrobial use (−9.75 DOT/1,000-PD per month) and broad-spectrum anti-gram-negative antimicrobial use (−4.00 DOT/1,000-PD) declined. After the introduction of prospective audit with feedback, however, both total antimicrobial use (+9.65 DOT/1,000-PD per month; P < .001) and broad-spectrum anti-gram-negative antimicrobial use (+4.80 DOT/1,000-PD per month; P < .001) increased significantly. Use of cefepime and piperacillin/tazobactam both significantly increased after the intervention (P = .03). Hospital LOS and LOS after first antimicrobial dose also significantly increased after the intervention (P = .016 and .004, respectively).

Significant increases in antimicrobial consumption and LOS were observed after the change in ASP strategy.

Infect Control Hosp Epidemiol 2014;35(9):1092-1099

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 assess the incidence of colonization and infection with carbapenemase-producing Enterobacteriaceae (CPE) and carbapenem-resistant Acinetobacter baumannii (CR-Ab) in the ICUs of our city hospitals before and during the coronavirus disease 2019 (COVID-19) pandemic.

We conducted a multicenter, before-and-after, cross-sectional study to compare the rates of colonization and infection with CPE and/or CR-Ab in 2 study periods, period 1 (January–April 2019) and period 2 (January–April 2020). Incidence rate ratios (IRRs) and 95% confidence intervals (CIs) of weekly colonization and infection rates for each period were compared for the 2 study periods using Poisson regression. Weekly trends in the incidence of colonization or infection for each study period were summarized using local weighted (Loess) regression.

We detected no significant change in either IRR and weekly trend in CPE colonization and infection during the 2 study periods. A shift from KPC to other CPE mechanisms (OXA-48 and VIM) was observed during period 2. Compared to period 1, during period 2 the IRR of colonization and infection with CR-Ab increased 7.5- and 5.5-fold, respectively. Genome sequencing showed that all CR-Ab strains belonged to the CC92/IC2 clonal lineage. Clinical strains clustered closely into a single monophyletic group in 1 of the 3 centers, whereas they segregated in 2 different clusters in the other 2 centers, which strongly indicates horizontal transmission.

Our findings indicate the need to conduct infection control activities targeted against the spread of antimicrobial resistance between and within hospitals during the COVID-19 pandemic, and if necessary, remodulating them according to the new organizational structures imposed by the pandemic.

To examine the association between hospital operation volume and surgeon operation volume and the risk of surgical site infection (SSI).

Prospective, multicenter cohort study based on surveillance data.

Data were obtained from the Dutch surveillance network for nosocomial infections (Preventie Ziekenhuisinfecties door Surveillance [PREZIES]) on 9 different types of orthopedic surgery, general surgery, and gynecology procedures performed during 1996-2003. Multilevel logistic regression analysis was performed to assess the independent effect of hospital volume and surgeon volume on SSI risk.

Hospital volume was not significantly associated with SSI risk for any of the selected procedures. Low surgeon volume was associated with an increased risk for an infection for 7 of 9 types of procedures, although this effect was statistically significant only for knee arthroplasty. For 4 procedures, the odds of exceeding the 75th percentile for duration of surgery were greater when the surgeon volume was low than when the surgeon volume was moderate or high.

Patients operated on by surgeons with a low operation volume seem to have a higher risk of developing an SSI with some procedures, particularly knee arthroplasty. The higher SSI risk for surgeons with a low operation volume is possibly partly mediated by the longer duration of surgery, a well-known risk factor for development of SSI.

Staphylococcus aureus is a common cause of healthcare-associated infections in neonates.

To examine the impact of methicillin-susceptible S. aureus (MSSA) decolonization on the incidence of MSSA infection and to measure the prevalence of mupirocin resistance.

We retrospectively identified neonates admitted to a tertiary care neonatal intensive care unit (NICU) from April 1, 2011, through September 30, 2014. We compared rates of MSSA-positive cultures and infections before and after implementation of an active surveillance culture and decolonization intervention for MSSA-colonized neonates. We used 2 measurements to identify the primary outcome, NICU-attributable MSSA: (1) any culture sent during routine clinical care that grew MSSA and (2) any culture that grew MSSA and met criteria of the National Healthcare Safety Network’s healthcare-associated infection surveillance definitions. S. aureus isolates were tested for mupirocin susceptibility. We estimated incidence rate ratios using interrupted time-series models.

Before and after the intervention, 1,523 neonates (29,220 patient-days) and 1,195 neonates (22,045 patient-days) were admitted to the NICU, respectively. There was an immediate reduction in the mean quarterly incidence rate of NICU-attributable MSSA-positive clinical cultures of 64% (incidence rate ratio, 0.36 [95% CI, 0.19–0.70]) after implementation of the intervention, and MSSA-positive culture rates continued to decrease by 21% per quarter (incidence rate ratio, 0.79 [95% CI, 0.74–0.84]). MSSA infections also decreased by 73% immediately following the intervention implementation (incidence rate ratio, 0.27 [95% CI, 0.10–0.79]). No mupirocin resistance was detected.

Active surveillance cultures and decolonization may be effective in decreasing S. aureus infections in NICUs.

Infect. Control Hosp. Epidemiol. 2016;37(4):381–387

To determine whether preoperative nasal methicillin-resistant Staphylococcus aureus (MRSA) carriage is a significant predictor of postoperative infections, after accounting for surgical infection risk and surgical prophylaxis.

Retrospective cohort study.

Veterans Affairs (VA) Boston patients who had nasal MRSA polymerase chain reaction screening performed in the 31 days before clean or clean contaminated surgery in 2008–2009.

Postoperative MRSA clinical cultures and infections, total surgical site infections (SSIs), and surgical prophylaxis data were abstracted from administrative databases. MRSA infections were confirmed via chart review. Multivariate analysis of risk factors for each outcome was conducted using Poisson regression. SSI risk index was calculated for a subset of 1,551 patients assessed by the VA National Surgical Quality Improvement Program.

Among 4,238 eligible patients, 279 (6.6%) were positive for preoperative nasal MRSA. Postoperative MRSA clinical cultures and infections, including MRSA SSIs, were each significantly increased in patients with preoperative nasal MRSA. After adjustment for surgery type, vancomycin prophylaxis, chlorhexidine/alcohol surgical skin preparation, and SSI risk index, preoperative nasal MRSA remained significantly associated with postoperative MRSA cultures (relative risk [RR], 8.81; 95% confidence interval [CI], 3.01–25.82) and infections (RR, 8.46; 95% CI, 1.70–42.04). Vancomycin prophylaxis was associated with an increased risk of total SSI in those negative for nasal MRSA (RR, 4.34; 95% CI, 2.19–8.57) but not in patients positive for nasal MRSA.

In our population, preoperative nasal MRSA colonization was independently associated with MRSA clinical cultures and infections in the postoperative period. Vancomycin prophylaxis increased the risk of total SSI in nasal MRSA-negative patients.

To identify institution-specific risk factors for MRSA bacteremia and develop an objective mechanism to estimate the probability of methicillin resistance in a given patient with Staphylococcus aureus bacteremia (SAB).

A cohort study was performed to identify institution-specific risk factors for MRSA. Logistic regression was used to model the likelihood of MRSA A stepwise approach was employed to derive a parsimonious model. The MRSA prediction tool was developed from the final model.

A 279-bed, level 1 trauma center.

Between January 1, 1999, and June 30, 2001, 494 patients with clinically significant episodes of SAB were identified.

The MRSA rate was 45.5%. Of 18 characteristics included in the logistic regression, the only independent features for MRSA were prior antibiotic exposure (OR, 9.2; CI95, 4.8 to 17.9), hospital onset (OR, 3.0; CI95, 1.9 to 4.9), history of hospitalization (OR, 2.5; CI95, 1.5 to 3.8), and presence of decubitus ulcers (OR, 2.5; CI95, 1.2 to 4.9). The prediction tool was derived from the final model, which was shown to accurately reflect the actual MRSA distribution in the cohort.

Through multivariate modeling techniques, we were able to identify the most important determinants of MRSA at our institution and develop a tool to predict the probability of methicillin resistance in a patient with SAB. This knowledge can be used to guide empiric antibiotic selection. In the era of antibiotic resistance, such tools are essential to prevent indiscriminate antibiotic use and preserve the longevity of current antimicrobials.

From 1990 to 1995 at Hospital Universitario dementino Fraga Filho, patients colonized or infected with methicillin-resistant Staphylococcus aureus (MRSA) were treated with mupirocin to eliminate MRSA carriage. In 1995, 65% of MRSA patients at this hospital had mupirocin-resistant isolates. Starting in 1996, mupirocin use was restricted to patients colonized, but not infected, with MRSA.

To describe the use of mupirocin for controlling MRSA over a decade and to analyze the molecular epidemiology of mupirocin-resistant MRSA infections at this hospital.

A 490-bed, tertiary-care university hospital.

The incidence densities of patients with MRSA and acquisition of mupirocin by the hospital were calculated for the period 1992–2001. S. aureus isolates from 1999–2000 were analyzed by pulsed-field gel electrophoresis. Mupirocin-resistant MRSA isolates from 1994–1995 and 1999–2000 were analyzed for ileS-2 gene background polymorphisms.

The incidence density of MRSA patients increased slightly over time, whereas the purchase of mupirocin decreased dramatically. Mupirocin-resistant MRSA infections decreased from 65% in 1994–1995 to 15% in 1999–2000. The MRSA Brazilian clone, detected in 1992, was still highly prevalent. The same ileS-2 encoding plasmid found in 1994–1995 persisted in three identical MRSA isolates from 1999–2000 belonging to the Brazilian clone.

After mupirocin use decreased, the ileS-2 encoding plasmid persisted in only a few Brazilian clone isolates. Our data on mupirocin-resistant MRSA incidence and mupirocin use strongly suggested that restricted use was related to decreased rates of mupirocin resistance at our hospital. (Infect Control Hosp Epidemiol 2005;26:662-667)

To determine the safety and cost-effectiveness of replacing the intravenous (TV) tubing sets in hospitalized patients at 4- to 7-day intervals instead of every 72 hours.

Prospective, randomized study of infusion-related contamination associated with changing IV tubing sets within 3 days versus within 4 to 7 days of placement.

A tertiary university cancer center.

Cancer patients requiring IV infusion therapy were randomized to have the IV tubing sets replaced within 3 days (280 patients) or within 4 to 7 days of placement (232 patients). Demographic, microbiological, and infusion-related data were collected for all participants. The main outcome measures were infusion- or catheter-related contamination or colonization of IV tubing, determined by quantitative cultures of the infusate, and infusion- or catheter-related bloodstream infection (BSI), determined by quantitative culture of the infusate in association with blood cultures in febrile patients.

The two groups were comparable in terms of patient and catheter characteristics and the agents given through the IV tubing. Intent-to-treat analysis demonstrated a higher level of tubing colonization in the 4- to 7-day group versus the 3-day group (median, 145 vs 50 colony-forming units; P=.02). In addition, there were three episodes of possible infusion-related BSIs, all of which occurred in the 4- to 7-day group (P=.09). However, when the 84 patients who received total parenteral nutrition, blood transfusions, or interleukin-2 through the IV tubing were excluded, the two groups had a comparable rate of colonization (0.4% vs 0.5%), with no catheter- or infusion-related BSIs in either group.

In patients at low risk for infection from infusion- or catheter-related infection who are not receiving total parenteral nutrition, blood transfusions, or interleukin-2, delaying the replacement of IV tubing up to 7 days may be safe, as well as cost-effective.

Carbapenem-resistant Enterobacteriaceae (CRE) are important extremely drug-resistant pathogens that have emerged during the past decade. Early identification and isolation of carriers are key components of an effective infection control strategy in healthcare facilities. Very little is known about the natural history of CRE carriage. We aimed to determine the predictors of a positive CRE rectal screen test among patients with known CRE carriage screened at their next hospital encounter.

A case-control study was conducted. Sixty-six patients who tested positive for CRE carriage were surveyed for CRE rectal carriage at the next hospital encounter; screen-positive patients were compared with screen-negative control patients. Data were extracted from the patients' medical records and from the hospital computerized database.

Twenty-three case patients and 43 control patients were identified. Predictors for a positive CRE rectal carriage test were (1) prior fluoroquinolone use (odds ratio [OR], 4.27; 95% confidence interval [CI], 1.10–16.6), (2) admission from an institution or another hospital (OR, 4.04; 95% CI, 1.33–12.37), and (3) time interval less than or equal to 3 months since the first positive CRE test (OR, 3.59; 95% CI, 1.24–10.37). Among patients with no predictor variables, the likelihood of having a positive screen test at the next hospital encounter was 1/7. If they had at least 1 predictor, the likelihood increased to 1/2.

Prior fluoroquinolone use, transfer from another healthcare facility, and admission less than or equal to 3 months since the first CRE isolation are predictors of persistent CRE rectal carriage. These predictors can be used in designing CRE prevention strategies.

To describe the molecular epidemiology of Legionella pneumophila infections in the University of Iowa Hospitals and Clinics (UIHC).

Molecular epidemiological study using pulsed-field gel electrophoresis (PFGE).

A large university teaching hospital.

All surviving isolates obtained from culture-proven nosocomial L pneumophila infections and all surviving isolates obtained from the University of Iowa Hospital and Clinics' water supply between 1981 and 1993.

Thirty-three isolates from culture-proven nosocomial cases of L pneumophila pneumonia were available for typing. PFGE of genomic DNA from the clinical isolates identified six different strains. However, only strain C (16 cases) and strain D (13 cases) caused more than 1 case. Strain C caused clusters of nosocomial infection in 1981, 1986, and 1993 and also caused 4 sporadic cases. Strain D caused a cluster in 1987 and 1988 plus 4 sporadic cases. Of the six strains causing clinical infections, only strains C and D were identified in water samples. PFGE identified three strains in the water supply, of which strains C and D caused clinical disease and also persisted in the water supply during most of the study period.

Specific strains of L pneumophila can colonize hospital water supplies and cause nosocomial infections over long periods of time.

Multidrug-resistant (MDR) gram-negative bacteria are reported increasingly frequently among isolates recovered from elderly patients. The clinical epidemiology of bloodstream infection (BSI) due to MDR gram-negative bacteria among elderly patients is unknown.

To characterize the clinical epidemiology of BSI due to MDR gram-negative bacteria among elderly patients at hospital admission in an effort to provide a greater understanding of these serious infections and ultimately to improve patient outcomes.

Case-control study.

Tertiary care hospital in Boston, Massachusetts.

Patients 65 years of age and older.

From 1999 to 2007, computerized medical records were reviewed for BSI due to MDR gram-negative bacteria within 48 hours of hospital admission. Risk factors for BSI due to these bacteria were identified.

MDR gram-negative bacteria were recovered from 61 (8%) of 724 elderly patients with BSI caused by gram-negative bacteria. Over the -year study period, the percentage of MDR gram-negative bacteria among bloodstream isolates increased from 2 (1%) of 199 to 34 (16%) of 216. Empiric therapy was ineffective for 38 (63%) of 60 patients with BSI caused by MDR gram-negative bacteria. The variables independently associated with BSI due to these bacteria were as follows: residency in a long-term care facility (odds ratio [OR], 4.9 [95% confidence interval {CI} 1.6–14.9]; P = .006), presence of an invasive device (OR, 6.0 [95% CI, 1.5–23.5]; P = .01), severe sepsis (OR, 7.9 [95% CI, 1.7–37.1]; P = .009), and delayed initiation of effective therapy (OR, 12.8 [95% CI, 3.9–41.1]; P<.001).

The 16-fold increase in BSI due to MDR gram-negative bacteria at hospital admission among elderly patients, especially among those who resided in long-term care facilities prior to admission, contributes further to the expanding body of evidence that these patients are the main reservoirs of MDR gram-negative bacteria. Given their contribution to the influx of antimicrobial-resistant bacteria in the hospital setting, infection control interventions that target this high-risk group need to be considered.

An improved understanding of the transmission dynamics of multidrug-resistant (MDR) gram-negative bacteria and the mechanism of acquisition in long-term care facilities (LTCFs) could aid in the development of prevention strategies specific to LTCFs. We thus investigated the incidence of acquisition of these pathogens among an LTCF population.

Prospective cohort study.

Three separate wards at a 600-bed LTCF in metropolitan Boston, Massachusetts, during the period October 31, 2006, through October 22, 2007.

One hundred seventy-two LTCF residents.

A series of rectal samples were cultured to determine acquisition of MDR gram-negative bacteria, defined as absence of MDR gram-negative bacterial colonization at baseline and de novo recovery of MDR gram-negative bacteria from a follow-up culture. Molecular typing was performed to identify genetically linked strains. A nested matched case-control study was performed to identify risk factors associated with acquisition.

Among 135 residents for whom at least 1 follow-up culture was performed, 52 (39%) acquired at least 1 MDR gram-negative organism during the study period. Thirty-two residents (62%) had not been colonized at baseline and had acquired at least 1 MDR gram-negative species at follow-up culture, and 20 residents (38%) were colonized at baseline and had acquired at least I MDR gram-negative species at follow-up culture. The most common coresistance pattern was resistance to extended-spectrum penicillins, ciprofloxacin, and gentamicin (57 isolates [42.5%]). Genetically related strains of MDR gram-negative bacteria were identified among multiple residents and between roommates. On conditional logistic regression analysis, antibiotic exposure during the study period was significantly associated with acquisition of MDR gram-negative bacteria (odds ratio, 5.6 [95% confidence interval, 1.1-28.7]; P = .04).

Acquisition of MDR gram-negative bacteria occurred frequently through resident-to-resident transmission. Existing infection control interventions need to be reevaluated.