To assess the prevalence of and risk factors for carbapenem-resistant Klebsiella pneumoniae (CRKP) carriage among patients in post-acute-care facilities (PACFs) in Israel.

A cross-sectional prevalence survey was conducted in 12 PACFs. Rectal swab samples were obtained from 1,144 patients in 33 wards. Risk factors for CRKP carriage were assessed among the cohort. Next, a nested, matched case-control study was conducted to define individual risk factors for colonization. Finally, the cohort of patients with a history of CRKP carriage was characterized to determine risk factors for continuous carriage.

The prevalence of rectal carriage of CRKP among 1,004 patients without a history of CRKP carriage was 12.0%. Independent risk factors for CRKP carriage were prolonged length of stay (odds ratio [OR], 1.001; P < .001), sharing a room with a known carrier (OR, 3.09; P = .02), and increased prevalence of known carriers on the ward (OR, 1.02; P = .013). A policy of screening for carriage on admission was protective (OR, 0.41; P = .03). Risk factors identified in the nested case-control study were antibiotic exposure during the prior 3 months (OR, 1.66; P = .03) and colonization with other resistant pathogens (OR, 1.64; P = .03). Among 140 patients with a history of CRKP carriage, 47% were colonized. Independent risk factors for continued CRKP carriage were antibiotic exposure during the prior 3 months (OR, 3.05; P = .04), receipt of amoxicillin-clavulanate (OR, 4.18; P = .007), and screening within 90 days of the first culture growing CRKP (OR, 2.9; P = .012).

We found a large reservoir of CRKP in PACFs. Infection-control polices and antibiotic exposure were associated with patient colonization.

Use of an alcohol-based hand rub for hand hygiene has recently been recommended by the Centers for Disease Control and Prevention. However, the proper technique for using hand rub has not been well described and is not routinely taught in hospitals.

To evaluate the impact of training on proper technique as outlined by the European Standard for testing alcohol-based hand rubs (European Norm 1500) in a clinical study.

Prospective study including 180 healthcare workers (HCWs) in a 450-bed, university-affiliated geriatric hospital where alcohol-based hand rub was introduced in the late 1970s.

Structured training program in hand hygiene with alcohol-based hand rub. Technique for using hand rub was tested by the addition of a fluorescent dye to the disinfectant and the number of areas missed was quantified by a validated visual assessment method. In addition, the number of bacteria eradicated was estimated by calculating the difference between the log10 number of colony-forming units (cfu) of bacteria on the fingertips before and after the procedure, and reported as reduction factor (RF).

Log10 cfu bacterial counts on fingertips before and after training in the appropriate technique for using hand rub.

At baseline, only 31% of HCWs used proper technique, yielding a low RF of 1.4 log10 cfu bacterial count. Training improved HCW compliance to 74% and increased the RF to 2.2 log10 cfu bacterial count, an increase of almost 50% (P < .001). Several factors, such as applying the proper amount of hand rub, were significantly associated with the increased RF.

These results demonstrate that education on the proper technique for using hand rub, as outlined in EN 1500, can significantly increase the degree of bacterial killing.

To determine the impact of antibiotic consumption and alcohol-based hand disinfection on the incidences of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) infection and Clostridium difficile infection (CDI).

Two multivariate time-series analyses were performed that used as dependent variables the monthly incidences of nosocomial MRSA infection and CDI at the Freiburg University Medical Center during the period January 2003 through October 2007. The volume of alcohol-based hand rub solution used per month was quantified in liters per 1,000 patient-days. Antibiotic consumption was calculated in terms of the number of defined daily doses per 1,000 patient-days per month.

The use of alcohol-based hand rub was found to have a significant impact on the incidence of nosocomial MRSA infection (P<.001). The multivariate analysis (R2 = 0.66) showed that a higher volume of use of alcohol-based hand rub was associated with a lower incidence of nosocomial MRSA infection. Conversely, a higher level of consumption of selected antimicrobial agents was associated with a higher incidence of nosocomial MRSA infection. This analysis showed this relationship was the same for the use of second-generation cephalosporins (P = .023), third-generation cephalosporins (P = .05), fluoroquinolones (P = .01), and lincosamides (P = .05). The multivariate analysis (R2 = 0.55) showed that a higher level of consumption of third-generation cephalosporins (P = .008), fluoroquinolones (P = .084), and/or macrolides (P = .007) was associated with a higher incidence of CDI. A correlation with use of alcohol-based hand rub was not detected.

In 2 multivariate time-series analyses, we were able to show the impact of hand hygiene and antibiotic use on the incidence of nosocomial MRSA infection, but we found no association between hand hygiene and incidence of CDI.

To determine effect of environmental exposure on the survival and infectivity of hepatitis C virus (HCV).

Three aliquots of chimpanzee plasma containing HCV and proven infectious HCV inoculum were dried and stored at room temperature, 1 aliquot for 16 hours, 1 for 4 days, and 1 for 7 days. A chimpanzee (CH247) was sequentially inoculated intravenously with each of these experimental inocula, beginning with the material stored for 7 days. Each inoculation was separated by at least 18 weeks of follow-up to monitor for infection. The concentration of HCV RNA was measured and quasi species were sequenced for each experimental inoculum and in serum samples from CH247.

Evidence of HCV infection developed in CH247 only after inoculation with the material stored for 16 hours. No infection occurred after inoculation with the material stored for 7 days or 4 days. Compared with the original infectious chimpanzee plasma, the concentration of HCV RNA was 1 log lower in all 3 experimental inocula. The same predominant sequences were found in similar proportions in the original chimpanzee plasma and in the experimental inocula, as well as in serum samples from CH247.

HCV in plasma can survive drying and environmental exposure to room temperature for at least 16 hours, which supports the results of recent epidemiologic investigations that implicated blood-contaminated inanimate surfaces, objects, and/or devices as reservoirs for patient-to-patient transmission of HCV. Healthcare professionals in all settings should review their aseptic techniques and infection control practices to ensure that they are being performed in a manner that prevents cross-contamination from such reservoirs.

To determine the role of nonmedicated soap as a source of Serratia marcescens nosocomial infections (NIs) in hospital units with endemic S marcescens NI and to examine the mechanisms of soap colonization.

University-affiliated tertiary-care hospitals.

A prospective case-control study and an environmental investigation were performed to assess the relationship between S marcescens NIs in hospital units and S marcescens-contaminated soap. Soap-bottle use and handwashing practices were reviewed. Cultures of healthcare workers’ (HCWs) hands were obtained before and after hand washing with soap.

5 of 7 hospital units with S marcescens NIs had soap bottles contaminated with S marcescens, compared to 1 of 14 other units (P =.006). After hand washing with an S marcescens-contaminated soap pump, HCWs' hands were 54 times more likely to be contaminated with S marcescens (P<.001).

Extrinsic contamination of a non-medicated liquid soap by S marcescens resulted in handborne transmission of S marcescens NIs by HCWs in our setting. This finding led to the application of strict guidelines for nonmedicated soap use and to the reinforcement of alcoholic hand disinfection.

To describe an outbreak of serious nosocomial Burkholderia cepacia infections occurring after transrectal prostate biopsy associated with ultrasound gel intrinsically contaminated with paraben-degrading microorganisms.

A retrospective chart review prompted by a blood culture isolate of B, cepacia. Identification of microorganisms in ultrasound gel in two Canadian centers and characterization by pulsed-field gel electrophoresis and assays for paraben degradation.

Two Canadian university-affiliated, tertiary-care centers in Newfoundland and Alberta.

Six serious B. cepacia infections were identified at the two centers. Isolates of B. cepacia recovered from the blood of patients from both centers and the ultrasound gel used during the procedures were identical, confirming intrinsic contamination. Strains of Enterobacter cloacae isolated from ultrasound gel at the two centers were also identical. The ability to degrade parabens was proven for both B. cepacia and E. cloacae strains recovered from the ultrasound gel.

Ultrasound gel is a potential source of infection. Contamination occurs at the time of manufacture, with organisms that degrade parabens, which are commonly used as stabilizing agents. There are far-reaching implications for the infection control community.

To perform active targeted prospective surveillance to measure device-associated infection (DAI) rates, attributable mortality due to DAI, and the microbiological and antibiotic resistance profiles of infecting pathogens at 10 intensive care units (ICUs) in 9 hospitals in Colombia, all of which are members of the International Infection Control Consortium.

We conducted prospective surveillance of healthcare-associated infection in 9 hospitals by using the definitions of the US Centers for Disease Control and Prevention National Nosocomial Surveillance System (NNIS). DAI rates were calculated as the number of infections per 100 ICU patients and per 1,000 device-days.

During the 3-year study, 2,172 patients hospitalized in an ICU for an aggregate duration of 14,603 days acquired 266 DAIs, for an overall DAI rate of 12.2%, or 18.2 DAIs per 1,000 patient-days. Central venous catheter (CVC)–related bloodstream infection (BSI) (47.4% of DAIs; 11.3 cases per 1,000 catheter-days) was the most common DAI, followed by ventilator-associated pneumonia (VAP) (32.3% of DAIs; 10.0 cases per 1,000 ventilator-days) and catheter-associated urinary tract infection (CAUTI) (20.3% of DAIs; 4.3 cases per 1,000 catheter-days). Overall, 65.4% of all Staphylococcus aureus infections were caused by methicillin-resistant strains; 40.0% of Enterobacteriaceae isolates were resistant to ceftriaxone and 28.3% were resistant to ceftazidime; and 40.0% of Pseudomonas aeruginosa isolates were resistant to fluoroquinolones, 50.0% were resistant to ceftazidime, 33.3% were resistant to piperacillin-tazobactam, and 19.0% were resistant to imipenem. The crude unadjusted attributable mortality was 16.9% among patients with VAP (relative risk [RR], 1.93; 95% confidence interval [CI], 1.24-3.00; P = .002); 18.5 among those with CVC-associated BSI (RR, 2.02; 95% CI, 1.42-2.87; P<.001); and 10.5% among those with CAUTI (RR, 1.58; 95% CI, 0.78-3.18; P = .19).

The rates of DAI in the Colombian ICUs were lower than those published in some reports from other Latin American countries and were higher than those reported in US ICUs by the NNIS. These data show the need for more-effective infection control interventions in Colombia.

To evaluate the impact of active screening for methicillin-resistant Staphylococcus aureus (MRSA) on MRSA infection rates and cost avoidance in units where the risk of MRSA transmission is high.

During a 15-month period, all patients admitted to our adult medical and surgical intensive care units (ICUs) were screened for MRSA nasal carriage on admission and weekly thereafter. The overall rates of all MRSA infections and of nosocomial MRSA infection in the 2 adult ICUs and the general wards were compared with rates during the 15-month period prior to the start of routine screening. The percentage of patients colonized or infected with MRSA on admission and the cost avoidance of the surveillance program were also assessed.

The overall rate of MRSA infections for all 3 areas combined decreased from 6.1 infections per 1,000 census-days in the preintervention period to 4.1 infections per 1,000 census-days in the postintervention period (P = .01). The decrease remained statistically significant when only nosocomial MRSA infections were examined (4.5 vs 2.8 infections per 1,000 census-days; P<.01), despite a corresponding increase during the postintervention period in the percentage of patients with onset of MRSA infection in the first 72 hours after admission to the general wards (46% to 81%; P<.005). A total of 3.7% of ICU patients were colonized or infected with MRSA on admission; MRSA would not have been detected in 91% of these patients if screening had not been performed. At a cost of $3,475/month for the program, we averted a mean of 2.5 MRSA infections/month for the ICUs combined, avoiding $19,714/month in excess cost in the ICUs.

Even in a setting of increasing community-associated MRSA, active MRSA screening as part of a multi-factorial intervention targeted to high-risk units may be an effective and cost-avoidant strategy for achieving a sustained decrease of MRSA infections throughout the hospital.

Carbapenem-resistant Klebsiella pneumoniae (CRKP) is resistant to almost all antimicrobial agents, and CRKP infections are associated with substantial morbidity and mortality.

To describe an outbreak of CRKP in Puerto Rico, determine risk factors for CRKP acquisition, and detail the successful measures taken to control the outbreak.

Two case-control studies.

A 328-bed tertiary care teaching hospital.

Twenty-six CRKP case patients identified during the outbreak period of February through September 2008, 26 randomly selected uninfected control patients, and 26 randomly selected control patients with carbapenem-susceptible K. pneumoniae (CSKP) hospitalized during the same period.

We performed active case finding, including retrospective review of the hospital's microbiology database and prospective perirectal surveillance culture sampling in high-risk units. Case patients were compared with each control group while controlling for time at risk. We sequenced the blaKPC gene with polymerase chain reaction for 7 outbreak isolates and subtyped these isolates with pulsed-field gel electrophoresis.

In matched, multivariable analysis, the presence of wounds (hazard ratio, 19.0 [95% confidence interval {CI}, 2.5-142.0]) was associated with CRKP compared with no K. pneumoniae. Transfer between units (adjusted odds ratio [OR], 7.5 [95% CI, 1.8-31.1]), surgery (adjusted OR, 4.0 [95% CI, 1.0-15.7]), and wounds (adjusted OR, 4.9 [95% CI, 1.1-21.8]) were independent risk factors for CRKP compared to CSKP. A novel K. pneumoniae carbapenemase variant (KPC-8) was present in 5 isolates. Implementation of active surveillance for CRKP colonization and cohorting of CRKP patients rapidly controlled the outbreak.

Enhanced surveillance for CRKP colonization and intensified infection control measures that include limiting the physical distribution of patients can reduce CRKP transmission during an outbreak.

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

A 900-bed tertiary care hospital.

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

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

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

To review evidence regarding the effectiveness of control measures in reducing transmission of methicillin-resistant Staphylococcus aureus (MRSA) in hospitals.

Literature review and surveillance cultures of hospitalized patients at high risk for MRSA colonization or infection.

A 500-bed, university-affiliated, community teaching hospital.

The percentage of nosocomial S. aureus infections caused by MRSA increased significantly between 1982 and 2002, despite the use of various isolation and barrier precaution policies. The apparent ineffectiveness of control measures may be due to several factors including the failure to identify patients colonized with MRSA For example, cultures of stool specimens submitted for Clostridium difficile toxin assays at one hospital found that 12% of patients had MRSA in their stool, and 41% of patients with unrecognized colonization were cared for without using barrier precautions. Other factors include the use of barrier precaution strategies that do not account for multiple reservoirs of MRSA, poor adherence of healthcare workers (HCWs) to recommended barrier precautions and handwashing, failure to identify and treat HCWs responsible for transmitting MRSA, and importation of MRSA by patients admitted from other facilities. Control programs that include active surveillance cultures (ASCs) of high-risk patients and use of barrier precautions have reduced MRSA prevalence rates and have been cost-effective. Using a staged approach to implementing ASCs can minimize logistic problems.

MRSA control programs are effective if they include ASCs of high-risk patients, use of barrier precautions when caring for colonized or infected patients, hand hygiene, and treating HCWs implicated in MRSA transmission.

Staphylococcus aureus is an important cause of infection in intensive care unit (ICU) patients. Colonization with methicillin-resistant S. aureus (MRSA) is a risk factor for subsequent S. aureus infection. However, MRSA-colonized patients may have more comorbidities than methicillin-susceptible S. aureus (MSSA)-colonized or noncolonized patients and therefore may be more susceptible to infection on that basis.

To determine whether MRSA-colonized patients who are admitted to medical and surgical ICUs are more likely to develop any S. aureus infection in the ICU, compared with patients colonized with MSSA or not colonized with S. aureus, independent of predisposing patient risk factors.

Prospective cohort study.

A 24-bed surgical ICU and a 19-bed medical ICU of a 1,252-bed, academic hospital.

A total of 9,523 patients for whom nasal swab samples were cultured for S. aureus at ICU admission during the period from December 2002 through August 2007.

Patients in the ICU for more than 48 hours were examined for an ICU-acquired S. aureus infection, defined as development of S. aureus infection more than 48 hours after ICU admission.

S. aureus colonization was present at admission for 1,433 (27.8%) of 5,161 patients (674 [47.0%] with MRSA and 759 [53.0%] with MSSA). An ICU-acquired S. aureus infection developed in 113 (2.19%) patients, of whom 75 (66.4%) had an infection due to MRSA. Risk factors associated with an ICU-acquired S. aureus infection included MRSA colonization at admission (adjusted hazard ratio, 4.70 [95% confidence interval, 3.07-7.21]) and MSSA colonization at admission (adjusted hazard ratio, 2.47 [95% confidence interval, 1.52-4.01]).

ICU patients colonized with S. aureus were at greater risk of developing a S. aureus infection in the ICU. Even after adjusting for patient-specific risk factors, MRSA-colonized patients were more likely to develop S. aureus infection, compared with MSSA-colonized or noncolonized patients.

Some policy makers have embraced public reporting of healthcare-associated infections (HAIs) as a strategy for improving patient safety and reducing healthcare costs. We compared the accuracy of 2 methods of identifying cases of HAI: review of administrative data and targeted active surveillance.

A cross-sectional prospective study was performed during a 9-month period in 2004 at the Children's Hospital of Philadelphia, a 418-bed academic pediatric hospital. “True HAI” cases were defined as those that met the definitions of the National Nosocomial Infections Surveillance System and that were detected by a trained infection control professional on review of the medical record. We examined the sensitivity and the positive and negative predictive values of identifying HAI cases by review of administrative data and by targeted active surveillance.

We found similar sensitivities for identification of HAI cases by review of administrative data (61%) and by targeted active surveillance (76%). However, the positive predictive value of identifying HAI cases by review of administrative data was poor (20%), whereas that of targeted active surveillance was 100%.

The positive predictive value of identifying HAI cases by targeted active surveillance is very high. Additional investigation is needed to define the optimal detection method for institutions that provide HAI data for comparative analysis.

To describe an outbreak of imipenem-resistant Acinetobacter baumannii (IR-Ab) and the measures for its control, and to investigate risk factors for IR-Ab acquisition.

An observational and a case-control study.

A surgical intensive care unit (ICU) in a university tertiary care hospital.

After admission to the ICU of an IR-Ab-positive patient, patients were prospectively screened for IR-Ab carriage upon admission and then once a week. Environmental cleaning and barrier safety measures were used for IR-Ab carriers. A case-control study was performed to identify factors associated with IR-Ab acquisition. Cases were patients who acquired IR-Ab. Controls were patients who were hospitalized in the ICU at the same time as cases and were exposed to IR-Ab for a similar duration as cases. The following variables were investigated as potential risk factors: baseline characteristics, scores for severity of illness and therapeutic intervention, presence and duration of invasive procedures, and antimicrobial administration.

Beginning in May 1996, the outbreak involved 17 patients over 9 months, of whom 12 acquired IR-Ab (cases), 4 had IR-Ab isolates on admission to the ICU, and 1 could not be classified. Genotypic analysis identified two different IR-Ab isolates, responsible for three clusters. Ten of the 12 nosocomial cases developed infection. Control measures included reinforcement of barrier safety measures, limitation of the number of admissions, and thorough environmental cleaning. No new case was identified after January 1997. Eleven of the 12 cases could be compared to 19 controls. After adjustment for severity of illness, a high individual therapeutic intervention score appeared to be a risk factor for IR-Ab acquisition.

The outbreak ended after strict application of control measures. Our results suggest that high work load contributes to IR-Ab acquisition.