To determine the effectiveness of daily bathing with 2% chlorhexidine-impregnated washcloths in preventing multidrug-resistant (MDR) gram-positive bacterial colonization and bloodstream infection.

A randomized, open-label controlled trial was conducted in 4 medical intensive care units (ICUs) in Thailand from December 2013 to January 2015. Patients were randomized to receive cleansing with non-antimicrobial soap (control group) or 2% chlorhexidine-impregnated washcloths used to wipe the patient’s body once daily (chlorhexidine group). Swabs were taken from nares, axilla, antecubital, groin, and perianal areas on admission and on day 3, 5, 7, and 14. The 5 outcomes were (1) favorable events ( all samples negative throughout ICU admission, or initially positive samples with subsequent negative samples); (2) MDR bacteria colonization-free time; (3) hospital-acquired infection; (4) length of ICU and hospital stay; (5) adverse skin reactions.

A total of 481 patients were randomly assigned to the control group (241) or the chlorhexidine group (240). Favorable events at day 14 were observed in 34.8% of patients in the control group and 28.6% in the chlorhexidine group (P=.79). Median MDR bacteria colonization-free times were 5 days in both groups. The incidence rate of hospital-acquired infection and the length of the ICU and hospital stay did not differ significantly between groups. The incidence of adverse skin reactions in the chlorhexidine group was 2.5%.

The effectiveness of 2% chlorhexidine-impregnated washcloths for the prevention of MDR gram-negative bacteria colonization and hospital-acquired infection in adult patients in ICU was not proven.

ClinicalTrials.gov identifier: NCT01989416.

Infect. Control Hosp. Epidemiol. 2016;37(3):245–253

Surgical site infections (SSIs) are responsible for significant morbidity and mortality. Preadmission skin antisepsis, while controversial, has gained acceptance as a strategy for reducing the risk of SSI. In this study, we analyze the benefit of an electronic alert system for enhancing compliance to preadmission application of 2% chlorhexidine gluconate (CHG).

Following informed consent, 100 healthy volunteers in an academic, tertiary care medical center were randomized to 5 chlorhexidine gluconate (CHG) skin application groups: 1, 2, 3, 4, or 5 consecutive applications. Participants were further randomized into 2 subgroups: with or without electronic alert. Skin surface concentrations of CHG (μg/mL) were analyzed using a colorimetric assay at 5 separate anatomic sites.

Preadmission application of chlorhexidine gluconate, 2%

Mean composite skin surface CHG concentrations in volunteer participants receiving EA following 1, 2, 3, 4, and 5 applications were 1,040.5, 1,334.4, 1,278.2, 1,643.9, and 1,803.1 µg/mL, respectively, while composite skin surface concentrations in the no-EA group were 913.8, 1,240.0, 1,249.8, 1,194.4, and 1,364.2 µg/mL, respectively (ANOVA, P<.001). Composite ratios (CHG concentration/minimum inhibitory concentration required to inhibit the growth of 90% of organisms [MIC90]) for 1, 2, 3, 4, or 5 applications using the 2% CHG cloth were 208.1, 266.8, 255.6, 328.8, and 360.6, respectively, representing CHG skin concentrations effective against staphylococcal surgical pathogens. The use of an electronic alert system resulted in significant increase in skin concentrations of CHG in the 4- and 5-application groups (P<.04 and P<.007, respectively).

The findings of this study suggest an evidence-based standardized process that includes use of an Internet-based electronic alert system to improve patient compliance while maximizing skin surface concentrations effective against MRSA and other staphylococcal surgical pathogens.

Infect. Control Hosp. Epidemiol. 2016;37(3):254–259

To develop and internally validate a surgical site infection (SSI) prediction model for Japan.

Retrospective observational cohort study.

We analyzed surveillance data submitted to the Japan Nosocomial Infections Surveillance system for patients who had undergone target surgical procedures from January 1, 2010, through December 31, 2012. Logistic regression analyses were used to develop statistical models for predicting SSIs. An SSI prediction model was constructed for each of the procedure categories by statistically selecting the appropriate risk factors from among the collected surveillance data and determining their optimal categorization. Standard bootstrapping techniques were applied to assess potential overfitting. The C-index was used to compare the predictive performances of the new statistical models with those of models based on conventional risk index variables.

The study sample comprised 349,987 cases from 428 participant hospitals throughout Japan, and the overall SSI incidence was 7.0%. The C-indices of the new statistical models were significantly higher than those of the conventional risk index models in 21 (67.7%) of the 31 procedure categories (P<.05). No significant overfitting was detected.

Japan-specific SSI prediction models were shown to generally have higher accuracy than conventional risk index models. These new models may have applications in assessing hospital performance and identifying high-risk patients in specific procedure categories.

Infect. Control Hosp. Epidemiol. 2016;37(3):260–271

The best strategy for controlling extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-PE) transmission in intensive care units (ICUs) remains elusive.

We developed a stochastic transmission model to quantify the effectiveness of interventions aimed at reducing the spread of ESBL-PE in an ICU.

We modeled the evolution of an outbreak caused by the admission of a single carrier in a 10-bed ICU free of ESBL-PE. Using data obtained from recent muticenter studies, we studied 26 strategies combining different levels of the following 3 interventions: (1) increasing healthcare worker compliance with hand hygiene before and after contact with a patient; (2) cohorting; (3) reducing antibiotic prevalence at admission with or without reducing antibiotherapy duration.

Improving hand hygiene compliance from 55% before patient contact and 60% after patient contact to 80% before and 80% after patient contact reduced the nosocomial incidence rate of ESBL-PE colonization by 91% at 90 days. Adding cohorting to hand hygiene improvement intervention decreased the proportion of ESBL-PE acquisitions by an additional 7%. Antibiotic restriction had the lowest impact on the epidemic. When combined with other interventions, it only marginally improved effectiveness, despite strong hypotheses regarding antibiotic impact on transmission.

Our results suggest that hand hygiene is the most effective intervention to control ESBL-PE transmission in an ICU.

Infect. Control Hosp. Epidemiol. 2016;37(3):272–280

Various transmission routes contribute to spread of carbapenem-resistant Klebsiella pneumoniae (CRKP) in hospitalized patients. Patients with readmissions during which CRKP is again isolated (“CRKP readmission”) potentially contribute to transmission of CRKP.

To evaluate CRKP readmissions in the Consortium on Resistance against Carbapenems in K. pneumoniae (CRaCKLe).

Cohort study from December 24, 2011, through July 1, 2013.

Multicenter consortium of acute care hospitals in the Great Lakes region.

All patients who were discharged alive during the study period were included. Each patient was included only once at the time of the first CRKP-positive culture.

All readmissions within 90 days of discharge from the index hospitalization during which CRKP was again found were analyzed. Risk factors for CRKP readmission were evaluated in multivariable models.

Fifty-six (20%) of 287 patients who were discharged alive had a CRKP readmission. History of malignancy was associated with CRKP readmission (adjusted odds ratio [adjusted OR], 3.00 [95% CI, 1.32–6.65], P<.01). During the index hospitalization, 160 patients (56%) received antibiotic treatment against CRKP; the choice of regimen was associated with CRKP readmission (P=.02). Receipt of tigecycline-based therapy (adjusted OR, 5.13 [95% CI, 1.72–17.44], using aminoglycoside-based therapy as a reference in those treated with anti-CRKP antibiotics) was associated with CRKP readmission.

Hospitalized patients with CRKP—specifically those with a history of malignancy—are at high risk of readmission with recurrent CRKP infection or colonization. Treatment during the index hospitalization with a tigecycline-based regimen increases this risk.

Infect. Control Hosp. Epidemiol. 2016;37(3):281–288

Vancomycin-resistant enterococci (VRE) have spread worldwide.

To systematically review VRE outbreaks and estimate the pooled basic reproductive rate (R0) of VRE.

Eligible studies criteria were (1) published within 10 years, (2) report outbreak details, (3) involve 1 center, (4) estimate epidemic duration, and (5) concern adults. Descriptive analysis included number of index cases, secondary cases, and screened patients; infection control measures; and definition of contact patients. R0 was estimated by the equation R0=(ln2) D/td+1, with D as the generation time and td as the doubling time.

Thirteen VRE outbreaks were retained from 180 articles and, among them, 10 were kept for R0 calculation. The mean (range) number of index cases was 2.3 (1–8) and the mean (range) number of secondary cases was 15 (3–56). The mean (range) number of screened patients was 174 (32–509), with pooled VRE prevalence of 5.4% (95% CI, 4.5%–6.3%). Contact precautions were reported in 12 studies (92%), wards were closed in 7 (54%), with cohorting in 6 (46%). Two major screening policies were implemented: (1) a surveillance program in the unit or hospital (7 studies [54%]) and (2) screening of selected contact patients (6 studies [46%]). The pooled R0 of VRE was 1.32 (interquartile range, 1.03–1.46).

We discerned considerable heterogeneity in screening policies during VRE outbreaks. Pooled R0 was higher than 1, confirming the epidemic nature of VRE.

Infect. Control Hosp. Epidemiol. 2016;37(3):289–394

A nationwide initiative was implemented in February 2014 to decrease Clostridium difficile infections (CDI) in Veterans Affairs (VA) long-term care facilities. We report a baseline of national CDI data collected during the 2 years before the Initiative.

Personnel at each of 122 reporting sites entered monthly retrospective CDI case data from February 2012 through January 2014 into a national database using case definitions similar to those used in the National Healthcare Safety Network Multidrug-Resistant Organism/CDI module. The data were evaluated using Poisson regression models to examine infection occurrences over time while accounting for admission prevalence and type of diagnostic test.

During the 24-month analysis period, there were 100,800 admissions, 6,976,121 resident days, and 1,558 CDI cases. The pooled CDI admission prevalence rate (including recurrent cases) was 0.38 per 100 admissions, and the pooled nonduplicate/nonrecurrent community-onset rate was 0.17 per 100 admissions. The pooled long-term care facility–onset rate and the clinically confirmed (ie, diarrhea or evidence of pseudomembranous colitis) long-term care facility–onset rate were 1.98 and 1.78 per 10,000 resident days, respectively. Accounting for diagnostic test type, the long-term care facility–onset rate declined significantly (P=.05), but the clinically confirmed long-term care facility–onset rate did not.

VA long-term care facility CDI rates were comparable to those in recent reports from other long-term care facilities. The significant decline in the long-term care facility-onset rate but not in the clinically confirmed long-term care facility–onset rate may have been due to less testing of asymptomatic patients. Efforts to decrease CDI rates in long-term care facilities are necessary as part of a coordinated approach to decrease healthcare-associated infections.

Infect. Control Hosp. Epidemiol. 2016;37(3):295–300

This study had 2 objectives: (1) to describe the epidemiology of catheter-related bloodstream infections (CRBSI) in patients with end-stage renal disease (ESRD) who have no access to scheduled dialysis and (2) to evaluate whether a positive culture of the heparin-lock solution is associated with subsequent development of bacteremia.

Retrospective observational cohort design for objective 1; and prospective cohort design for objective 2.

The study was conducted in a 770-bed public academic tertiary hospital in Dallas, Texas. The participants were patients with ESRD undergoing scheduled or emergent hemodialysis.

We reviewed the records of 147 patients who received hemodialysis between January 2011 and May 2011 and evaluated the rate of CRBSI in the previous 5 years. For the prospective study, we cultured the catheter heparin-lock solution in 62 consecutive patients between June 2012 and August 2012 and evaluated the incidence of CRBSI at 6 months.

Of the 147 patients on emergent hemodialysis, 125 had a tunneled catheter, with a CRBSI rate of 2.61 per 1,000 catheter days. The predominant organisms were Gram-negative rods (GNR). In the prospective study, we found that the dialysis catheter was colonized more frequently in patients on emergent hemodialysis than in those on scheduled hemodialysis. Colonization with GNR or Staphylococcus aureus was associated with subsequent CRBSI at 6 months follow-up.

Patients undergoing emergent hemodialysis via tunneled catheter are predisposed to Gram-negative CRBSI. Culturing the heparin-lock solution may predict subsequent episodes of CRBSI if it shows colonization with GNR or Staphylococcus aureus. Prevention approaches in this population need to be studied further.

Infect. Control Hosp. Epidemiol. 2016;37(3):301–305

To describe an outbreak of severe Group A Streptococcus (GAS) infections that appeared to be associated with use of a biologic dermal substitute on foot wounds

Retrospective cohort study of cases and similar uninfected patients

Patients attending the podiatry clinic at a Veterans Affairs Medical Center between July 2011 and November 2011

Microbiology laboratory data were reviewed for the calendar year, a case definition was established and use of the biologic dermal substitute was discontinued. Staff were cultured to identify potentially colonized employees. A case–cohort study was designed to investigate risk factors for disease. Emm typing and pulsed field gel electrophoresis (PFGE) were performed to identify strain similarity.

In 10 months, 14 cases were identified, and 4 of these patients died. All strains were emm type 28 and were identical according to PFGE. Discontinuation of biologic dermal substitute use halted the outbreak. A prior stroke was more common in the case cohort vs uninfected patient cohorts. The number of patients attending the clinic on 13 probable transmission days was significantly higher than on nontransmission days. We identified 2 patients who were present in the clinic on all but 1 probable transmission day. Surveillance cultures of podiatry clinic staff and cultures of the same lot of retained graft material were negative.

A carrier was not identified, and we believe the outbreak was associated with inter-patient transmission likely due to lapses in infection control techniques. No additional cases have been identified in >3 years following the resumption of dermal substitute use in May 2012.

Infect. Control Hosp. Epidemiol. 2016;37(3):306–312

To describe current Ebola treatment center (ETC) locations, their capacity to care for Ebola virus disease patients, and infection control infrastructure features.

A 19-question survey was distributed electronically in April 2015. Responses were collected via email by June 2015 and analyzed in an electronic spreadsheet.

The survey was sent to and completed by site representatives of each ETC.

The survey was sent to all 55 ETCs; 47 (85%) responded.

Of the 47 responding ETCs, there are 84 isolation beds available for adults and 91 for children; of these pediatric beds, 35 (38%) are in children’s hospitals. In total, the simultaneous capacity of the 47 reporting ETCs is 121 beds. On the basis of the current US census, there are 0.38 beds per million population. Most ETCs have negative pressure isolation rooms, anterooms, and a process for category A waste sterilization, although only 11 facilities (23%) have the capability to sterilize infectious waste on site.

Facilities developed ETCs on the basis of Centers for Disease Control and Prevention guidance, but specific capabilities are not mandated at this present time. Owing to the complex and costly nature of Ebola virus disease treatment and variability in capabilities from facility to facility, in conjunction with the lack of regulations, nationwide capacity in specialized facilities is limited. Further assessments should determine whether ETCs can adapt to safely manage other highly infectious disease threats.

Infect. Control Hosp. Epidemiol. 2016;37(3):313–318

Antibiotic treatment for asymptomatic bacteriuria (ASB) is prevalent but often contrary to published guidelines.

To evaluate risk factors for treatment of ASB.

Retrospective observational study.

A tertiary academic hospital, county hospital, and community hospital.

Hospitalized adults with bacteriuria.

Patients without documented symptoms of urinary tract infection per Infectious Diseases Society of America (IDSA) criteria were classified as ASB. We examined ASB treatment risk factors as well as broad-spectrum antibiotic usage and quantified diagnostic concordance between IDSA and National Healthcare Safety Network criteria.

Among 300 patients with bacteriuria, ASB was present in 71% by IDSA criteria. By National Healthcare Safety Network criteria, 71% of patients had ASB; within-patient diagnostic concordance with IDSA was moderate (kappa, 0.52). After excluding those given antibiotics for nonurinary indications, antibiotics were given to 38% (62/164) with ASB. Factors significantly associated with ASB treatment were elevated urine white cell count (65 vs 24 white blood cells per high-powered field, P<.01), hospital identity (hospital C vs A, odds ratio, 0.34 [95% CI, 0.14–0.80], P =.01), presence of leukocyte esterase (5.48 [2.35–12.79], P<.01), presence of nitrites (2.45 [1.11–5.41], P=.03), and Escherichia coli on culture (2.4 [1.2–4.7], P=.01). Of patients treated for ASB, broad-spectrum antibiotics were used in 84%.

ASB treatment was prevalent across settings and contributed to broad-spectrum antibiotic use. Associating abnormal urinalysis results with the need for antibiotic treatment regardless of symptoms may drive unnecessary antibiotic use.

Infect. Control Hosp. Epidemiol. 2016;37(3):319–326