New technologies have emerged in recent years for the disinfection of hospital rooms and equipment that may not be disinfected adequately using conventional methods. There are several hydrogen peroxide–based area decontamination technologies on the market, but no head-to-head studies have been performed.

We conducted a head-to-head in vitro comparison of a hydrogen peroxide vapor (HPV) system (Bioquell) and an aerosolized hydrogen peroxide (aHP) system (Sterinis).

The tests were conducted in a purpose-built 136-m3 test room.

One HPV generator and 2 aHP machines were used, following recommendations of the manufacturers. Three repeated tests were performed for each system. The microbiological efficacy of the 2 systems was tested using 6-log Tyvek-pouched Geobacillus stearo-thermophilus biological indicators (BIs). The indicators were placed at 20 locations in the first test and 14 locations in the subsequent 2 tests for each system.

All BIs were inactivated for the 3 HPV tests, compared with only 10% in the first aHP test and 79% in the other 2 aHP tests. The peak hydrogen peroxide concentration was 338 ppm for HPV and 160 ppm for aHP. The total cycle time (including aeration) was 3 and 3.5 hours for the 3 HPV tests and the 3 aHP tests, respectively. Monitoring around the perimeter of the enclosure with a handheld sensor during tests of both systems did not identify leakage.

One HPV generator was more effective than 2 aHP machines for the inactivation of G. stearothermophilus BIs, and cycle times were faster for the HPV system.

Healthcare-associated outbreaks and pseudo-outbreaks of rapidly growing mycobacteria (RGM) are frequently associated with contaminated tap water. A pseudo-outbreak of Mycobacterium chelonae–M. abscessus in patients undergoing bronchoscopy was identified by 2 acute care hospitals. RGM was identified in bronchoscopy specimens of 28 patients, 25 of whom resided in the same skilled nursing facility (SNF). An investigation ruled out bronchoscopy procedures, specimen collection, and scope reprocessing at the hospitals as sources of transmission.

To identify the reservoir for RGM within the SNF and evaluate 2 water system treatments, hyperchlorination and point-of-use (POU) membrane filters, to reduce RGM.

A comparative in situ study of 2 water system treatments to prevent RGM transmission.

An SNF specializing in care of patients requiring ventilator support.

RGM and heterotrophic plate count (HPC) bacteria were examined in facility water before and after hyperchlorination and in a subsequent 24-week assessment of filtered water by colony enumeration on Middlebrook and R2A media.

Mycobacterium chelonae was consistently isolated from the SNF water supply. Hyperchlorination reduced RGM by 1.5 log10 initially, but the population returned to original levels within 90 days. Concentration of HPC bacteria also decreased temporarily. RGM were reduced below detection level in filtered water, a 3-log10 reduction. HPC bacteria were not recovered from newly installed filters, although low quantities were found in water from 2-week-old filters.

POU membrane filters may be a feasible prevention measure for healthcare facilities to limit exposure of sensitive individuals to RGM in potable water systems.

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.

To investigate potential sources and risks associated with multidrug-resistant (MDR) bacteria in a deployed US military hospital.

Retrospective analysis of factors associated with recovery of MDR bacteria, supplemented by environmental sampling.

The largest US military hospital in Afghanistan.

US and Afghan patients with positive bacterial culture results, from September 2007 through August 2008.

Microbiologic, demographic, and clinical data were analyzed. Potential risk factors included admission diagnosis or mechanism of injury, length of stay, gender, age, and nationality (US or Afghan). Environmental sampling of selected hospital high-touch surfaces and equipment was performed to help elucidate whether environmental MDR bacteria were contributing to nosocomial spread.

A total of 266 patients had 411 bacterial isolates that were identified during the study period, including 211 MDR bacteria (51%). Gram-negative bacteria were common among Afghan patients (241 [76%] of 319), and 70% of these were classified as MDR. This included 58% of bacteria recovered from Afghan patients within 48 hours of hospital admission. The most common gram-negative bacteria were Escherichia coli (53% were MDR), Acinetobacter (90% were MDR), and Klebsiella (63% were MDR). Almost one-half of potential extended-spectrum β-lactamase (ESBL) producers were community acquired. Of 100 environmental swab samples, 18 yielded MDR bacteria, including 10 that were Acinetobacter, but no potential ESBL-producing bacteria.

Gram-negative bacteria from Afghan patients had high rates of antimicrobial resistance. Patients experiencing Complex trauma and prolonged hospital stays likely contribute to the presence of MDR bacteria in this facility. However, many of these patients had community-acquired cases, which implies high rates of colonization prior to hospital admission.

Carbapenem-resistant Enterobacteriaceae (CRE) are rapidly emerging in hospitals in the United States and are posing a significant threat. To better understand the transmission dynamics and the acquisition of resistant strains, a thorough analysis of epidemiologic and molecular characteristics was performed.

CRE isolated at Detroit Medical Center were analyzed from September 2008 to September 2009. blaKPC genes were investigated by polymerase chain reaction (PCR), and repetitive extragenic palindromic PCR (rep-PCR) was used to determine genetic similarity among strains. Epidemiologic and outcomes analyses were performed.

Ninety-two unique patient CRE isolates were recovered. Sixty-eight strains (74%) were Klebsiella pneumoniae, 7 were Klebsiella oxytoca, 15 were Enterobacter species, and 2 were Escherichia coli. Fifteen isolates (16%) were resistant to Colistin, 14 (16%) were resistant to tigecycline, and 2 were resistant to all antimicrobials tested. The mean ± standard deviation age of patients was 63 ± 2 years. Sixty patients (68%) were admitted to the hospital from long-term care facilities. Only 70% of patients received effective antimicrobial therapy when infection was suspected, with a mean time to appropriate therapy of 120 ± 23 hours following sample culturing. The mean length of hospitalization after sample culturing was 18.6 ± 2.5 days. Of 57 inpatients, 18 (32%) died in the hospital. Independent predictors for mortality were intensive care unit stay (odds ratio [OR], 15.8; P = .003) and co-colonization with CRE and either Acinetobacter baumannii or Pseudomonas aeruginosa (OR, 17.2; P = .006). Among K. pneumoniae CRE, rep-PCR revealed 2 genetically related strains that comprised 70% and 20% of isolates, respectively.

In this large U.S. cohort of patients with CRE infection, which reflects the modern continuum of medical care, co-colonization with CRE and A. baumannii or P. aeruginosa was associated with increased mortality. Two predominant clones of K. pneumoniae accounted for the majority of cases of CRE infection.

Despite a paucity of evidence, decolonization measures are prescribed for outpatients with recurrent Staphylococcus aureus skin and soft-tissue infection (SSTI).

Compare the effectiveness of 4 regimens for eradicating S. aureus carriage.

Open-label, randomized controlled trial. Colonization status and recurrent SSTI were ascertained at 1 and 4 months.

Barnes-Jewish and St. Louis Children's Hospitals, St. Louis, Missouri, 2007–2009.

Three hundred patients with community-onset SSTI and S. aureus colonization in the nares, axilla, or inguinal folds.

Participants were randomized to receive no therapeutic intervention (control subjects) or one of three 5-day regimens: 2% mupirocin ointment applied to the nares twice daily, intranasal mupirocin plus daily 4% chlorhexidine body washes, or intranasal mupirocin plus daily dilute bleach water baths.

Among 244 participants with 1-month colonization data, modified intention-to-treat analysis revealed S. aureus eradication in 38% of participants in the education only (control) group, 56% of those in the mupirocin group (P = .03 vs controls), 55% of those in the mupirocin and chlorhexidine group (P = .05), and 63% off those in the mupirocin and bleach group (P = .006). Of 229 participants with 4-month colonization data, eradication rates were 48% in the control group, 56% in the mupirocin only group (P = .40 vs controls), 54% in the mupirocin and chlorhexidine group (P = .51), and 71% in the mupirocin and bleach group (P = .02). At 1 and 4 months, recurrent SSTIs were reported by 20% and 36% of participants, respectively.

An inexpensive regimen of dilute bleach baths, intranasal mupirocin, and hygiene education effectively eradicated S. aureus over a 4-month period. High rates of recurrent SSTI suggest that factors other than endogenous colonization are important determinants of infection.

ClinicalTrials.gov identifier: NCT00513799.

To describe the epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) carriage and transmission in an ambulatory hemodialysis population.

Prospective cohort study.

Outpatient hemodialysis facility affiliated with a large academic medical center.

Of the 170 facility patients, 103 (61%) participated in the study.

Swab specimens of the nares, axillae, and vascular access site were collected from participants weekly for 3 weeks and then monthly for 5 months. Demographic and clinical data were collected monthly for 12 months. Molecular analysis of MRSA isolates was performed.

The baseline MRSA carriage prevalence was 12%. Factors associated with MRSA carriage included a history of MRSA; failed renal transplantation; hospital admission within 6 months; and receipt of a first-generation cephalosporin, cefepime, or vancomycin. Six subjects acquired MRSA after enrollment (incidence, 1.2 per 100 patient-months at-risk; overall prevalence, 18%). Molecular analysis suggested that transmission occurred within the facility. The incidence of MRSA infection among carriers was 1.76 per 100 patient-months. Community-associated strains (ie, USA300) were isolated from 28% of carriers and at least 25% of infections.

The prevalence of MRSA carriage and the incidence of infection among carriers were high among ambulatory hemodialysis patients, and community-associated MRSA was responsible for a large portion of the MRSA burden. A relatively high rate of MRSA acquisition was observed, with indirect evidence of intrafacility transmission. Additional studies are needed to confirm these findings and to identify effective and feasible methods to prevent MRSA transmission and infection among hemodialysis patients.

To estimate the proportion of patients who acquire methicillin-resistant Staphylococcus aureus (MRSA) while in hospital and to identify risk factors associated with acquisition of MRSA.

Retrospective cohort study.

Adult patients discharged from 36 general specialty wards of 2 Scottish hospitals that had implemented universal screening for MRSA on admission.

Patients were screened for MRSA on discharge from hospital by using multisite body swabs that were tested by culture. Discharge screening results were linked to admission screening results. Genotyping was undertaken to identify newly acquired MRSA in MRSA-positive patients on admission.

Of the 5,155 patients screened for MRSA on discharge, 2.9% (95% confidence interval [CI], 2.43–3.34) were found to be positive. In the subcohort screened on both admission and discharge (n = 2,724), 1.3% of all patients acquired MRSA while in hospital (incidence rate, 2.1/1,000 hospital bed-days in this cohort [95% CI, 1.5–2.9]), while 1.3% remained MRSA positive throughout hospital stay. Three risk factors for acquisition of MRSA were identified: age above 64 years, self-reported renal failure, and self-reported presence of open wounds. On a population level, the prevalence of MRSA colonization did not differ between admission and discharge.

Cross-transmission of MRSA takes place in Scottish hospitals that have implemented universal screening for MRSA. This study reinforces the importance of infection prevention and control measures to prevent MRSA cross-transmission in hospitals; universal screening for MRSA on admission will in itself not be sufficient to reduce the number of MRSA colonizations and subsequent MRSA infections.

Describe the clinical and molecular epidemiology of incident Clostridium difficile infection (CDI) cases in Chicago area acute healthcare facilities (HCFs).

Laboratory, clinical, and epidemiologic information was collected for patients with incident CDI who were admitted to acute HCFs in February 2009. Stool cultures and restriction endonuclease analysis typing of the recovered C. difficile isolates was performed.

Two hundred sixty-three patients from 25 acute HCFs.

Acute HCF rates ranged from 2 to 7 patients with CDI per 10,000 patient-days. The crude mortality rate was 8%, with 20 deaths occurring in patients with CDI. Forty-two (16%) patients had complications from CDI, including 4 patients who required partial, subtotal, or total colectomy, 3 of whom died. C. difficile was isolated and typed from 129 of 178 available stool specimens. The BI strain was identified in 79 (61%) isolates. Of patients discharged to long-term care who had their isolate typed, 36 (67%) had BI-associated CDI.

Severe disease was common and crude mortality was substantial among patients with CDI in Chicago area acute HCFs in February 2009. The outbreak-associated BI strain was the predominant endemic strain identified, accounting for nearly two-thirds of cases. Focal HCF outbreaks were not reported, despite the presence of the BI strain. Transfer of patients between acute and long-term HCFs may have contributed to the high incidence of BI cases in this investigation.

To analyze a decade of hospital staff and student exposures to blood and body fluids (BBF) and to identify risk factors relevant to prevention strategies.

Retrospective review of a 1999–2008 data set of BBF exposures. The data, maintained by occupational health staff, detailed the type of exposure, the setting in which the exposure occurred, and the occupational group of the BBF-exposed personnel.

Washington DC Veterans Affairs Medical Center (VA-DC), an inner-city tertiary care hospital.

All healthcare workers and staff at the VA-DC.

Review of database.

A review of 10 years of data revealed 564 occupational exposures to BBF, of which 66% were caused by needlesticks and 20% were caused by sharp objects. Exposures occurred most often in the acute care setting (which accounted for 39% of exposures) and the operating room (which accounted for 22%). There was a mean of 4.9 exposures per 10,000 acute care patient-days, 0.5 exposures per 10,000 long-term care patient-days, and 0.35 exposures per 10,000 outpatient visits. Housestaff accounted for the highest number of all exposures (196 [35%]). There were, on average, 15.2 exposures per 100 housestaff full-time equivalents. An average of only 1 exposure per year occurred in the hemodialysis center.

Occupational exposures to BBF remain common, but rates vary widely by setting and occupational group. Overall rates are steady across a decade, despite the use of various antiexposure devices and provider education programs. Targeting occupational groups and hospital settings that have been shown to have the highest risk rates should become foundational to future preventative strategies.