To determine whether copper incorporated into hospital ward furnishings and equipment can reduce their surface microbial load.

A crossover study.

Acute care medical ward with 19 beds at a large university hospital.

Fourteen types of frequent-touch items made of copper alloy were installed in various locations on an acute care medical ward. These included door handles and push plates, toilet seats and flush handles, grab rails, light switches and pull cord toggles, sockets, overbed tables, dressing trolleys, commodes, taps, and sink fittings. Their surfaces and those of equivalent standard items on the same ward were sampled once weekly for 24 weeks. The copper and standard items were switched over after 12 weeks of sampling to reduce bias in usage patterns. The total aerobic microbial counts and the presence of indicator microorganisms were determined.

Eight of the 14 copper item types had microbial counts on their surfaces that were significantly lower than counts on standard materials. The other 6 copper item types had reduced microbial numbers on their surfaces, compared with microbial counts on standard items, but the reduction did not reach statistical significance. Indicator microorganisms were recovered from both types of surfaces; however, significantly fewer copper surfaces were contaminated with vancomycin-resistant enterococci, methicillin-susceptible Staphylococcus aureus, and coliforms, compared with standard surfaces.

Copper alloys (greater than or equal to 58% copper), when incorporated into various hospital furnishings and fittings, reduce the surface microorganisms. The use of copper in combination with optimal infection-prevention strategies may therefore further reduce the risk that patients will acquire infection in healthcare environments.

Infect Control Hosp Epidemiol 2012;33(1):3-9

To assess the effectiveness of selective digestive decontamination (SDD) for eradicating carbapenem-resistant Klebsiella pneumoniae (CRKP) oropharyngeal and gastrointestinal carriage.

A randomized, double-blind, placebo-controlled trial with 7 weeks of follow-up per patient.

A 1,000-bed tertiary-care university hospital.

Adults with CRKP-positive rectal swab cultures.

Patients were blindly randomized (1:1) over a 20-month period. The SDD arm received oral gentamicin and polymyxin E gel (0.5 g 4 times per day) and oral solutions of gentamicin (80 mg 4 times per day) and polymyxin E (1 × 106 units 4 times per day for 7 days). The placebo arm received oral placebo gel 4 times per day and 2 placebo oral solutions 4 times per day for 7 days. Strict contact precautions were applied. Samples obtained from the throat, groin, and urine were also cultured.

Forty patients (mean age ± standard deviation, 71 ± 16 years; 65% male) were included. At screening, greater than or equal to 30% of oropharyngeal, greater than or equal to 60% of skin, and greater than or equal to 35% of urine cultures yielded CRKP isolates. All throat cultures became negative in the SDD arm after 3 days (P< .0001). The percentages of rectal cultures that were positive for CRKP were significandy reduced at 2 weeks. At that time, 16.1% of rectal cultures in the placebo arm and 61.1% in the SDD arm were negative (odds ratio, 0.13; 95% confidence interval, 0.02–0.74; P<.0016). A difference between the percentages in the 2 arms was still maintained at 6 weeks (33.3% vs 58.5%). Groin colonization prevalence did not change in either arm, and the prevalence of urine colonization increased in the placebo arm.

This SDD regimen could be a suitable decolonization therapy for selected patients colonized with CRKP, such as transplant recipients or immunocompromised patients pending chemotherapy and patients who require major intestinal or oropharyngeal surgery. Moreover, in outbreaks caused by CRKP infections that are uncontrolled by routine infection control measures, SDD could provide additional infection containment.

Infect Control Hosp Epidemiol 2012;33(1):14-19

Clostridium difficile infection (CDI) is associated with hospitalization and may cause readmission following admission for any reason. We aimed to measure the incidence of readmissions due to CDI.

Retrospective cohort study.

Adult inpatients in Orange County, California, who presented with new-onset CDI within 12 weeks of discharge.

We assessed mandatory 2000–2007 hospital discharge data for trends in hospital-associated CDI (HA-CDI) incidence, with and without inclusion of postdischarge CDI (PD-CDI) events resulting in rehospitalization within 12 weeks of discharge. We measured the effect of including PD-CDI events on hospital-specific CDI incidence, a mandatory reporting measure in California, and on relative hospital ranks by CDI incidence.

From 2000 to 2007, countywide hospital-onset CDI (HO-CDI) incidence increased from 15 per 10,000 to 22 per 10,000 admissions. When including PD-CDI events, HA-CDI incidence doubled (29 per 10,000 in 2000 and 52 per 10,000 in 2007). Overall, including PD-CDI events resulted in significantly higher hospital-specific CDI incidence, although hospitals had disproportionate amounts of HA-CDI occurring postdischarge. This resulted in substantial shifts in some hospitals' rankings by CDI incidence. In multivariate models, both HO and PD-CDI were associated with increasing age, higher length of stay, and select comorbidities. Race and Hispanic ethnicity were predictive of PD-CDI but not HO-CDI.

PD-CDI events associated with rehospitalization are increasingly common. The majority of HA-CDI cases may be occurring postdischarge, raising important questions about both accurate reporting and effective prevention strategies. Some risk factors for PD-CDI may be different than those for HO-CDI, allowing additional identification of high-risk groups before discharge.

Infect Control Hosp Epidemiol 2012;33(1):20-28

Most cases of necrotizing enterocolitis (NEC) are sporadic, but outbreaks in hospital settings suggest an infectious cause. Our neonatal intensive care unit (NICU) experienced an outbreak of methicillin-sensitive Staphylococcus aureus (MSSA). We aimed to assess whether the enhancement of infection prevention and control measures would be associated with a reduction in the number of cases of NEC.

Retrospective chart review.

A 24-bed, university-affiliated, inborn level 3 NICU.

Infants of less than 30 weeks gestation or birth weight ≤ 1,500 g admitted to the NICU between January 2007 and December 2008 were considered at risk of NEC. All cases of NEC were reviewed.

Infection prevention and control measures, including hand hygiene education, were enhanced during the outbreak. Avoidance of overcapacity in the NICU was reinforced, environmental services (ES) measures were enhanced, and ES hours were increased.

Two hundred eighty-two at-risk infants were admitted during the study. Their gestational age and birth weight (mean ± SD) were 28.2 ± 2.7 weeks and 1,031 ± 290 g, respectively. The proportion of NEC was 18/110 (16.4%) before the outbreak, 1/54 (1.8%) during the outbreak, and 4/118 (3.4%) after the outbreak. After adjustment for gestational age, birth weight, gender, and singleton versus multiple births, the proportion was lower in the postoutbreak period than in the preoutbreak period (P< .002).

Although this observational study cannot establish a causal relationship, there was a significant decrease in the incidence of NEC following implementation of enhanced infection prevention and control measures to manage an MSSA outbreak.

Infect Control Hosp Epidemiol 2012;33(1):29-33

To investigate the relationship between contact precautions and delirium among inpatients, adjusting for other factors.

Retrospective cohort study.

A 662-bed tertiary care center.

All nonpyschiatric adult patients admitted to a tertiary care center from 2007 through 2009.

Generalized estimating equations were used to estimate the association between contact precautions and delirium in a retrospective cohort of 2 years of admissions to a tertiary care center.

During the 2-year period, 60,151 admissions occurred in 45,266 unique nonpsychiatric patients. After adjusting for comorbid conditions, age, sex, intensive care unit status, and length of hospitalization, contact precautions were significantly associated with delirium (as denned by International Classification of Diseases, Ninth Revision), medication, or restraint exposure (adjusted odds ratio [OR], 1.40 [95% confidence interval {CI}, 1.24–1.51]). The association between contact precautions and delirium was seen only in patients who were newly placed under contact precautions during the course of their stay (adjusted OR, 1.75 [95% CI, 1.60–1.92]; P< .01) and was not seen in patients who were already under contact precautions at admission (adjusted OR, 0.97 [95% CI, 0.86–1.09]; P = .60).

Although delirium was more common in patients who were newly placed under contact precautions during the course of their hospital admission, delirium was not associated with contact precautions started at hospital admission. Patients newly placed under contact precautions after admission but during hospitalization appear to be at a higher risk and may benefit from proven delirium-prevention strategies.

Infect Control Hosp Epidemiol 2012;33(1):34-39

To evaluate the use of routinely collected electronic health data in Medicare claims to identify surgical site infections (SSIs) following hip arthroplasty, knee arthroplasty, and vascular surgery.

Retrospective cohort study.

Four academic hospitals that perform prospective SSI surveillance.

We developed lists of International Classification of Diseases, Ninth Revision, and Current Procedural Terminology diagnosis and procedure codes to identify potential SSIs. We then screened for these codes in Medicare claims submitted by each hospital on patients older than 65 years of age who had undergone 1 of the study procedures during 2007. Each site reviewed medical records of patients identified by either claims codes or traditional infection control surveillance to confirm SSI using Centers for Disease Control and Prevention/ National Healthcare Safety Network criteria. We assessed the performance of both methods against all chart-confirmed SSIs identified by either method.

Claims-based surveillance detected 1.8–4.7-fold more SSIs than traditional surveillance, including detection of all previously identified cases. For hip and vascular surgery, there was a 5-fold and 1.6-fold increase in detection of deep and organ/space infections, respectively, with no increased detection of deep and organ/space infections following knee surgery. Use of claims to trigger chart review led to confirmation of SSI in 1 out of 3 charts for hip arthroplasty, 1 out of 5 charts for knee arthroplasty, and 1 out of 2 charts for vascular surgery.

Claims-based SSI surveillance markedly increased the number of SSIs detected following hip arthroplasty, knee arthroplasty, and vascular surgery. It deserves consideration as a more effective approach to target chart reviews for identifying SSIs.

Infect Control Hosp Epidemiol 2012;33(1):40-49

Although central venous catheter (CVC) dwell time is a major risk factor for catheter-related bloodstream infections (CR-BSIs), few studies reveal how often CVCs are retained when not needed (“idle”). We describe use patterns for temporary CVCs, including peripherally inserted central catheters (PICCs), on non-ICU wards.

A retrospective observational study.

A 579-bed acute care, academic tertiary care facility.

A retrospective observational study of a random sample of patients on hospital wards who have a temporary, nonimplanted CVC, with a focus on on daily ward CVC justification. A uniform definition of idle CVC-days was used.

We analyzed 89 patients with 146 CVCs (56% of which were PICCs); of 1,433 ward CVC-days, 361 (25.2%) were idle. At least 1 idle day was observed for 63% of patients. Patients had a mean of 4.1 idle days and a mean of 3.4 days with both a CVC and a peripheral intravenous catheter (PIV). After adjusting for ward length of stay, mean CVC dwell time was 14.4 days for patients with PICCs versus 9.0 days for patients with non-PICC temporary CVCs (other CVCs; P< .001). Patients with a PICC had 5.4 days in which they also had a PIV, compared with 10 days in other CVC patients (P< .001). Patients with PICCs had more days in which the only justification for the CVC was intravenous administration of antimicrobial agents (8.5 vs 1.6 days; P = .0013).

Significant proportions of ward CVC-days were unjustified. Reducing “idle CVC-days” and facilitating the appropriate use of PIVs may reduce CVC-days and CR-BSI risk.

Infect Control Hosp Epidemiol 2012;33(1):50-57

To evaluate the seroprevalence and risk factors for 2009 influenza A (H1N1) virus infection among healthcare personnel.

Observational cross-sectional study.

Healthcare workers (HCWs) in an acute care hospital.

Between September 14 and October 4, 2009, before 2009 H1N1 vaccination, we collected serological samples from 461 healthy HCWs. Hemagglutination-inhibition antibody assays were conducted. To evaluate the risk factors of seropositivity for 2009 H1N1 virus, gender, age, profession, work department, usage of personal protective equipment, and seasonal influenza vaccination status data were gathered via questionnaires.

Our survey showed that doctors and nurses were at highest risk of seropositivity for the 2009 H1N1 virus (odds ratio [OR], 5.25 [95% confidence interval {CI}, 1.21–22.7]). An increased risk of seropositivity was observed among pediatric, emergency room, and internal medicine staff (adjusted OR, 1.98 [95% CI, 1.07–3.65]). Risk was also higher among HCWs who had high titers of antibodies against the seasonal H1N1 virus (adjusted OR, 1.59 [95% CI, 1.02–2.48]).

Seropositivity for the 2009 H1N1 virus was associated with occupational risk factors among HCWs.

Infect Control Hosp Epidemiol 2012;33(1):58-62

Assessing the relative success of serial strategies for increasing healthcare personnel (HCP) influenza vaccination rates is important to guide hospital policies to increase vaccine uptake.

To evaluate serial campaigns that include a mandatory HCP vaccination policy and to describe HCP attitudes toward vaccination and reasons for declination.

Retrospective cohort study.

We assessed the impact of serial vaccination campaigns on the proportions of HCP who received influenza vaccination during die 2006–2011 influenza seasons. In addition, declination data over these 5 seasons and a 2007 survey of HCP attitudes toward vaccination were collected.

HCP influenza vaccination rates increased from 44.0% (2,863 of 6,510 HCP) to 62.9% (4,037 of 6,414 HCP) after institution of mobile carts, mandatory declination, and peer-to-peer vaccination efforts. Despite maximal attempts to improve accessibility and convenience, 27.2% (66 of 243) of die surveyed HCP were unwilling to wait more than 10 minutes for a free influenza vaccination, and 23.3% (55 of 236) would be indifferent if they were unable to be vaccinated. In this context, institution of a mandatory vaccination campaign requiring unvaccinated HCP to mask during the influenza season increased rates of compliance to over 90% and markedly reduced the proportion of HCP who declined vaccination as a result of preference.

A mandatory influenza vaccination program for HCP was essential to achieving high vaccination rates, despite years of intensive vaccination campaigns focused on increasing accessibility and convenience. Mandatory vaccination policies appear to successfully capture a large portion of HCP who are not opposed to receipt of die vaccine but who have not made vaccination a priority.

Infect Control Hosp Epidemiol 2012;33(1):63-70