To evaluate the association of airborne colony-forming units (CFU) at incision sites during implantation of prostheses with the incidence of either incisional or prosthesis-related surgical site infections.

Randomized, controlled trial.

Primary, public institution.

Three hundred patients undergoing total hip arthroplasty, instrumented spinal procedures, or vascular bypass graft implantation.

Patients were randomly assigned in a 1:1 ratio to either the intervention group or the control group. A novel device (Air Barrier System), previously shown to reduce airborne CFU at incision sites, was utilized in the intervention group. Procedures assigned to the control group were performed without the device, under routine operating room atmospheric conditions. Patients were followed up for 12 months to determine whether airborne CFU levels at the incision sites predicted the incidence of incisional or prosthesis-related infection.

Data were available for 294 patients, 148 in the intervention group and 146 in the control group. CFU density at the incision site was significantly lower in the intervention group than in the control group (P<.001). The density of airborne CFU at the incision site during the procedures was significantly related to the incidence of implant infection (P=.021). Airborne CFU densities were 4 times greater in procedures with implant infection versus no implant infection. All 4 of the observed prosthesis infections occurred in the control group.

Reduction of airborne CFU specifically at the incision site during operations may be an effective strategy to reduce prosthesis-related infections. Trial Registration: clinicaltrials.gov Identifier: NCT01610271

Infect Control Hosp Epidemiol 2016;1–8

To evaluate invasiveness index as a potential predictor of spine surgical site infection (SSI) after spinal fusion, revision fusion, or laminectomy.

Retrospective cohort study.

Single, large, academic medical center.

Adults undergoing spinal fusion, revision fusion, or laminectomy.

Data were obtained from electronic hospital databases; cases of SSI were extracted from the infection control database using National Healthcare Safety Network (NHSN) definitions. For each case, an invasiveness index, determined by surgical approach, procedure, and number of spine levels treated, was calculated using current procedural terminology (CPT) billing codes. Statistical analyses were performed using univariate and multivariate logistic regression models.

In total, 3,143 patients met inclusion criteria, and 43 of these developed SSI. Multivariate regression showed that advanced age (odds ratio [OR], 1.03; 95% confidence interval [CI], 1.005–1.05, for each year of life) and invasiveness index (medium invasiveness index OR, 5.36; 95% CI, 1.92–14.96; high invasiveness index OR, 14.1; 95% CI, 4.38–45.43) were significant predictors of infection. In subgroup analyses of spinal fusion patients, morbid obesity (OR, 2.542; 95% CI, 1.08–5.99), trauma (OR, 2.41; 95% CI, 1.05–5.55), and invasiveness index (medium invasiveness index OR, 5.39; 95% CI, 1.56–18.61; high invasiveness index OR, 13.44; 95% CI, 3.28–55.01) were significant predictors of SSI. Models containing invasiveness index were compared to NHSN models and demonstrated similar performance.

Invasiveness index is a predictor of SSI after spinal fusion and performs similarly to NHSN models. Invasiveness index shows promise as a potential risk stratification tool that is easily calculated and is available preoperatively.

Infect Control Hosp Epidemiol 2016:1–7

Infections and colonization with multidrug-resistant organisms (MDROs) identified >48 hours after hospital admission are considered healthcare-acquired according to the definition of the Centers for Disease Control and Prevention (CDC). Some may originate from delayed diagnosis rather than true acquisition in the hospital, potentially diluting the impact of infection control programs. In addition, such infections are not necessarily reimbursed in a healthcare system based on the diagnosis-related groups (DRGs).

The goal of the study was to estimate the preventable proportion of healthcare-acquired infections in a tertiary care hospital in Switzerland by analyzing patients colonized or infected with MDROs.

All hospitalized patients with healthcare-acquired MDRO infection or colonization (HAMIC) or according to the CDC definition (CDC-HAMIC) were prospectively assessed from 2002 to 2011 to determine whether there was evidence for nosocomial transmission. We utilized an additional work-up with epidemiological, microbiological, and molecular typing data to determine the true preventable proportion of HAMICs.

Overall, 1,190 cases with infection or colonization with MDROs were analyzed; 274 (23.0%) were classified as CDC-HAMICs. Only 51.8% of CDC-HAMICs had confirmed evidence of hospital-acquisition and were considered preventable. Specifically, 57% of MRSA infections, 83.3% of VRE infections, 43.9% of ESBL infections, and 74.1% of non-ESBL MDRO infections were preventable HAMICs.

The CDC definition overestimates the preventable proportion of HAMICs with MDROs by more than 50%. Relying only on the CDC definition of HAMICs may lead to inaccurate measurement of the impact of infection control interventions and to inadequate reimbursement under the DRG system.

Infect. Control Hosp. Epidemiol. 2016;1–6

To assess clinically relevant outcomes after complete cessation of control measures for vancomycin-resistant enterococci (VRE).

Quasi-experimental ecological study over 3.5 years.

All VRE screening and isolation practices at 4 large academic hospitals in Ontario, Canada, were stopped on July 1, 2012. In total, 618 anonymized abstracted charts of patients with VRE-positive clinical isolates identified between July 1, 2010, and December 31, 2013, were reviewed to determine whether the case was a true VRE infection, a VRE colonization or contaminant, or a true VRE bacteremia. All deaths within 30 days of the last VRE infection were also reviewed to determine whether the death was fully or partially attributable to VRE. All-cause mortality was evaluated over the study period. Generalized estimating equation methods were used to cluster outcome rates within hospitals, and negative binomial models were created for each outcome.

The incidence rate ratio (IRR) for VRE infections was 0.59 and the associated P value was .34. For VRE bacteremias, the IRR was 0.54 and P=.38; for all-cause mortality the IRR was 0.70 and P=.66; and for VRE attributable death, the IRR was 0.35 and P=.49. VRE control measures were not significantly associated with any of the outcomes. Rates of all outcomes appeared to increase during the 18-month period after cessation of VRE control measures, but none reached statistical significance.

Clinically significant VRE outcomes remain rare. Cessation of all control measures for VRE had no significant attributable adverse clinical impact.

Infect Control Hosp Epidemiol 2016;1–7

To evaluate the impact of multidrug-resistant gram-negative rod (MDR-GNR) infections on mortality and healthcare resource utilization in community hospitals.

Two matched case-control analyses.

Six community hospitals participating in the Duke Infection Control Outreach Network from January 1, 2010, through December 31, 2012.

Adult patients admitted to study hospitals during the study period.

Patients with MDR-GNR bloodstream and urinary tract infections were compared with 2 groups: (1) patients with infections due to nonMDR-GNR and (2) control patients representative of the nonpsychiatric, non-obstetric hospitalized population. Four outcomes were assessed: mortality, direct cost of hospitalization, length of stay, and 30-day readmission rates. Multivariable regression models were created to estimate the effect of MDR status on each outcome measure.

No mortality difference was seen in either analysis. Patients with MDR-GNR infections had 2.03 higher odds of 30-day readmission compared with patients with nonMDR-GNR infections (95% CI, 1.04–3.97, P=.04). There was no difference in hospital direct costs between patients with MDR-GNR infections and patients with nonMDR-GNR infections. Hospitalizations for patients with MDR-GNR infections cost $5,320.03 more (95% CI, $2,366.02–$8,274.05, P<.001) and resulted in 3.40 extra hospital days (95% CI, 1.41–5.40, P<.001) than hospitalizations for control patients.

Our study provides novel data regarding the clinical and financial impact of MDR gram-negative bacterial infections in community hospitals. There was no difference in mortality between patients with MDR-GNR infections and patients with nonMDR-GNR infections or control patients.

Infect Control Hosp Epidemiol 2016;1–8

To evaluate the impact of no-touch terminal room no-touch disinfection using ultraviolet wavelength C germicidal irradiation (UVGI) on C. difficile infection (CDI) rates on inpatient units with persistently high rates of CDI despite infection control measures.

Interrupted time-series analysis with a comparison arm.

3 adult hematology-oncology units in a large, tertiary-care hospital.

We conducted a 12-month prospective valuation of UVGI. Rooms of patients with CDI or on contact precautions were targeted for UVGI upon discharge using an electronic patient flow system. Incidence rates of healthcare-onset CDI were compared for the baseline period (January 2013–December 2013) and intervention period (February 2014–January 2015) on study units and non–study units using a mixed-effects Poisson regression model with random effects for unit and time in months.

During a 52-week intervention period, UVGI was deployed for 542 of 2,569 of all patient discharges (21.1%) on the 3 study units. The CDI rate declined 25% on study units and increased 16% on non-study units during the intervention compared to the baseline period. We detected a significant association between UVGI and decrease in CDI incidence (incidence rate ratio [IRR], 0.49; 95% confidence interval [CI], 0.26–0.94; P=.03) on the study units but not on the non-study units. The impact of UVGI use on average room-cleaning time and turnaround time was negligible compared to the baseline period.

Targeted deployment of UVGI to rooms of high-risk patients at discharge resulted in a substantial reduction of CDI incidence without adversely impacting room turnaround.

Infect Control Hosp Epidemiol 2016;1–6

Considerable efforts have been dedicated to developing strategies to prevent and treat recurrent Clostridium difficile infection (rCDI); however, evidence of the impact of rCDI on patient healthcare utilization and outcomes is limited.

To compare healthcare utilization and 1-year mortality among adults who had rCDI, nonrecurrent CDI, or no CDI.

We performed a nested case-control study among adult Kaiser Foundation Health Plan members from September 1, 2001, through December 31, 2013. We identified CDI through the presence of a positive laboratory test result and divided patients into 3 groups: patients with rCDI, defined as CDI in the 14–57 days after initial CDI; patients with nonrecurrent CDI; and patients who never had CDI. We conducted 3 matched comparisons: (1) rCDI vs no CDI; (2) rCDI vs nonrecurrent CDI; (3) nonrecurrent CDI vs no CDI. We followed patients for 1 year and compared healthcare utilization between groups, after matching patients on age, sex, and comorbidity.

We found that patients with rCDI consistently have substantially higher levels of healthcare utilization in various settings and greater 1-year mortality risk than both patients who had nonrecurrent CDI and patients who never had CDI.

Patients who develop an initial CDI are generally characterized by excess underlying, severe illness and utilization. However, patients with rCDI experience even greater adverse consequences of their disease than patients who do not experience rCDI. Our results further support the need for continued emphasis on identifying and using novel approaches to prevent and treat rCDI.

Infect Control Hosp Epidemiol. 2016;1–8

To examine self-reported practices and policies to reduce infection and transmission of multidrug-resistant organisms (MDRO) in healthcare settings outside the United States.

Cross-sectional survey.

International members of the Society for Healthcare Epidemiology of America (SHEA) Research Network.

Electronic survey of infection control and prevention practices, capabilities, and barriers outside the United States and Canada. Participants were stratified according to their country’s economic development status as defined by the World Bank as low-income, lower-middle-income, upper-middle-income, and high-income.

A total of 76 respondents (33%) of 229 SHEA members outside the United States and Canada completed the survey questionnaire, representing 30 countries. Forty (53%) were high-, 33 (43%) were middle-, and 1 (1%) was a low-income country. Country data were missing for 2 respondents (3%). Of the 76 respondents, 64 (84%) reported having a formal or informal antibiotic stewardship program at their institution. High-income countries were more likely than middle-income countries to have existing MDRO policies (39/64 [61%] vs 25/64 [39%], P=.003) and to place patients with MDRO in contact precautions (40/72 [56%] vs 31/72 [44%], P=.05). Major barriers to preventing MDRO transmission included constrained resources (infrastructure, supplies, and trained staff) and challenges in changing provider behavior.

In this survey, a substantial proportion of institutions reported encountering barriers to implementing key MDRO prevention strategies. Interventions to address capacity building internationally are urgently needed. Data on the infection prevention practices of low income countries are needed.

Infect Control Hosp Epidemiol. 2016:1–8

To measure transmission frequencies and risk factors for household acquisition of community-associated and healthcare-associated (HA-) methicillin-resistant Staphylococcus aureus (MRSA).

Prospective cohort study from October 4, 2008, through December 3, 2012.

Seven acute care hospitals in or near Toronto, Canada.

Total of 99 MRSA-colonized or MRSA-infected case patients and 183 household contacts.

Baseline interviews were conducted, and surveillance cultures were collected monthly for 3 months from household members, pets, and 8 prespecified high-use environmental locations. Isolates underwent pulsed-field gel electrophoresis and staphylococcal cassette chromosome mec typing.

Overall, of 183 household contacts 89 (49%) were MRSA colonized, with 56 (31%) detected at baseline. MRSA transmission from index case to contacts negative at baseline occurred in 27 (40%) of 68 followed-up households. Strains were identical within households. The transmission risk for HA-MRSA was 39% compared with 40% (P=.95) for community-associated MRSA. HA-MRSA index cases were more likely to be older and not practice infection control measures (P=.002–.03). Household acquisition risk factors included requiring assistance and sharing bath towels (P=.001–.03). Environmental contamination was identified in 78 (79%) of 99 households and was more common in HA-MRSA households.

Household transmission of community-associated and HA-MRSA strains was common and the difference in transmission risk was not statistically significant.

Infect Control Hosp Epidemiol 2016;1–7

Patients are frequently discharged with central venous catheters (CVCs) for home infusion therapy.

To study a prospective cohort of patients receiving home infusion therapy to identify environmental and other risk factors for complications.

Prospective cohort study between March and December 2015.

Home infusion therapy after discharge from academic medical centers.

Of 368 eligible patients discharged from 2 academic hospitals to home with peripherally inserted central catheters and tunneled CVCs, 222 consented. Patients remained in the study until 30 days after CVC removal.

Patients underwent chart abstraction and monthly telephone surveys while the CVC was in place, focusing on complications and environmental exposures. Multivariable analyses estimated adjusted odds ratios and adjusted incident rate ratios between clinical, demographic, and environmental risk factors and 30-day readmissions or CVC complications.

Of 222 patients, total parenteral nutrition was associated with increased 30-day readmissions (adjusted odds ratio, 4.80 [95% CI, 1.51–15.21) and CVC complications (adjusted odds ratio, 2.41 [95% CI, 1.09–5.33]). Exposure to soil through gardening or yard work was associated with a decreased likelihood of readmissions (adjusted odds ratio, 0.09 [95% CI, 0.01–0.74]). Other environmental exposures were not associated with CVC complications.

complications and readmissions were common and associated with the use of total parenteral nutrition. Common environmental exposures (well water, cooking with raw meat, or pets) did not increase the rate of CVC complications, whereas soil exposures were associated with decreased readmissions. Interventions to decrease home CVC complications should focus on total parenteral nutrition patients.

Infect Control Hosp Epidemiol 2016;1–8

To assess the impact of an antimicrobial stewardship program (ASP) on antibiotic consumption, Clostridium difficile infections (CDI), and antimicrobial resistance patterns in a rehabilitation hospital.

Quasi-experimental study of the periods before (from January 2011 to June 2012) and after (from July 2012 to December 2014) ASP implementation.

150-bed rehabilitation hospital dedicated to patients with spinal-cord injuries.

Beginning in July 2012, an ASP was implemented based on systematic bedside infectious disease (ID) consultation and structural interventions (ie, revision of protocols for antibiotic prophylaxis and education focused on the appropriateness of antibiotic prescriptions). Antibiotic consumption, occurrence of CDI, and antimicrobial resistance patterns of selected microorganisms were compared between periods before and after the ASP implementation.

Antibiotic consumption decreased from 42 to 22 defined daily dose (DDD) per 100 patient days (P<.001). The main reductions involved carbapenems (from 13 to 0.4 DDD per 100 patient days; P=.01) and fluoroquinolones (from 11.8 to 0.99 DDD per 100 patient days; P=.006), with no increases in mortality or length of stay. The incidence of CDI decreased from 3.6 to 1.2 cases per 10,000 patient days (P=.001). Between 2011 and 2014, the prevalence of extensively drug-resistant (XDR) strains decreased from 55% to 12% in P. aeruginosa (P<.001) and from 96% to 73% in A. baumannii (P=.03). The prevalence of ESBL-producing strains decreased from 42% to 17% in E. coli (P=.0007) and from 62% to 15% in P. mirabilis (P=.0001). In K. pneumoniae, the prevalence of carbapenem-resistant strains decreased from 42% to 17% (P=.005), and the prevalence of in methicillin-resistant S. aureus strains decreased from 77% to 40% (P<.0008).

An ASP based on ID consultation was effective in reducing antibiotic consumption without affecting patient outcomes and in improving antimicrobial resistance patterns in a rehabilitation hospital.

Infect Control Hosp Epidemiol. 2016;1–7

To assess knowledge about infection prevention among nursing home personnel and identify gaps potentially addressable through a quality improvement collaborative.

Baseline knowledge assessment of catheter-associated urinary tract infection, asymptomatic bacteriuria, antimicrobial stewardship, and general infection prevention practices for healthcare-associated infections.

Nursing homes across 14 states participating in the national “Agency for Healthcare Research and Quality Safety Program for Long-Term Care: Healthcare-Associated Infections/Catheter-Associated Urinary Tract Infection.”

Licensed (RNs, LPNs, APRNs, MDs) and unlicensed (clinical nursing assistants) healthcare personnel.

Each facility aimed to obtain responses from at least 10 employees (5 licensed and 5 unlicensed). We assessed the percentage of correct responses.

A total of 184 (78%) of 236 participating facilities provided 1 response or more. Of the 1,626 respondents, 822 (50.6%) were licensed; 117 facilities (63.6%) were for-profit. While 99.1% of licensed personnel recognized the definition of asymptomatic bacteriuria, only 36.1% knew that pyuria could not distinguish a urinary tract infection from asymptomatic bacteriuria. Among unlicensed personnel, 99.6% knew to notify a nurse if a resident developed fever or confusion, but only 27.7% knew that cloudy, smelly urine should not routinely be cultured. Although 100% of respondents reported receiving training in hand hygiene, less than 30% knew how long to rub hands (28.5% licensed, 25.2% unlicensed) or the most effective agent to use (11.7% licensed, 10.6% unlicensed).

This national assessment demonstrates an important need to enhance infection prevention knowledge among healthcare personnel working in nursing homes to improve resident safety and quality of care.

Infect. Control Hosp. Epidemiol. 2016;1–6

To assess the likelihood of antimicrobial streamlining between 2 antimicrobial stewardship methods.

Retrospective cohort study.

Large academic medical center.

Frequency and time to antimicrobial streamlining were compared during a prior authorization and a prospective audit period. Streamlining was defined as an antimicrobial change to a narrower agent if available or to a broader agent if the isolate was resistant to empiric therapy. Patients included were ≥18 years old with monomicrobial bacteremia with S. aureus, Enterococcus spp., or any aerobic Gram-negative organism.

A total of 665 cases of bacteremia met inclusion criteria. Frequency of streamlining was similar between periods for all cases of bacteremia (audit vs restriction: 60.7% vs 53.2%; P=.12), S. aureus bacteremia (73.2% vs 76.9%; P=.671), and Enterococcus bacteremia (81.6% vs 71.9%; P=.335). Compared to restriction, the audit period was associated with an increased frequency of streamlining for cases of Gram-negative bacteremia (51.4% vs 35.6%; odds ratio [OR], 1.85; 95% confidence interval [CI], 1.06–3.25), those on the medical service (67.9% vs 53.1%; OR, 1.86; 95% CI, 1.09–3.16), and those admitted through the emergency department (71.6% vs 51.4%; OR, 2.32; 95% CI, 1.24–4.34). Characteristics associated with increased streamlining included: absence of β-lactam allergy (P<.001), Gram-negative bacteremia (P<.001), admission through the emergency department (P=.001), and admission to a medical service (P=.011).

Compared with prior authorization, prospective audit increased antimicrobial streamlining for cases of Gram-negative bacteremia, those admitted through the emergency department, and those admitted to a medical but not surgical service.

Infect Control Hosp Epidemiol 2016:1–7

To evaluate 2 different methods of surveillance and to estimate the incidence of norovirus (NoV) outbreaks in hospitals.

Prospective observational study.

All 194 hospital wards in southern Sweden during 2 winter seasons (2010–2012).

Clinical surveillance based on outbreak reports of 2 or more clinical cases, with symptom onset within 5 days, was compared with laboratory surveillance based on positive NoV results among inpatients. At least 2 NoV positive patients sampled within 5 days at a ward defined a cluster. Outbreak reports including at least 1 NoV positive case and clusters including at least 1 NoV positive patient with 5 or more days from ward admission to sampling were defined as NoV outbreaks.

During the study periods 135 NoV outbreaks were identified; 74 were identified by both clinical and laboratory surveillance, 18 were identified only by outbreak reports, and 43 were identified only by laboratory surveillance. The outbreak incidence was 1.0 (95% CI, 0.8–1.2) and 0.5 (95% CI, 0.3–0.6) per 1,000 admissions for the 2 different seasons, respectively. To correctly identify NoV outbreaks, the sensitivity and positive predictive value of the clinical surveillance were 68% and 88% and of the laboratory surveillance were 86% and 81%, respectively.

The addition of laboratory surveillance significantly improves outbreak surveillance and provides a more complete estimate of NoV outbreaks in hospitals. Laboratory surveillance can be recommended for evaluation of clinical surveillance.

Infect Control Hosp Epidemiol 2016;1–7