To identify clinical signs and symptoms (ie, “terms”) that accurately predict laboratory-confirmed influenza cases and thereafter generate and evaluate various influenza-like illness (ILI) case definitions for detecting influenza. A secondary objective explored whether surveillance of data beyond the chief complaint improves the accuracy of predicting influenza.

Retrospective, cross-sectional study.

Large urban academic medical center hospital.

A total of 1,581 emergency department (ED) patients who received a nasopharyngeal swab followed by rRT-PCR testing between August 30, 2009, and January 2, 2010, and between November 28, 2010, and March 26, 2011.

An electronic surveillance system (GUARDIAN) scanned the entire electronic medical record (EMR) and identified cases containing 29 clinical terms relevant to influenza. Analyses were conducted using logistic regressions, diagnostic odds ratio (DOR), sensitivity, and specificity.

The best predictive model for identifying influenza for all ages consisted of cough (DOR=5.87), fever (DOR=4.49), rhinorrhea (DOR=1.98), and myalgias (DOR=1.44). The 3 best case definitions that included combinations of some or all of these 4 symptoms had comparable performance (ie, sensitivity=89%–92% and specificity=38%–44%). For children <5 years of age, the addition of rhinorrhea to the fever and cough case definition achieved a better balance between sensitivity (85%) and specificity (47%). For the fever and cough ILI case definition, using the entire EMR, GUARDIAN identified 37.1% more influenza cases than it did using only the chief complaint data.

A simplified case definition of fever and cough may be suitable for implementation for all ages, while inclusion of rhinorrhea may further improve influenza detection for the 0–4-year-old age group. Finally, ILI surveillance based on the entire EMR is recommended.

Infect Control Hosp Epidemiol 2015;00(0): 1–8

To determine whether there is a difference in antibody titers and functionality after receipt of the influenza vaccine for obese versus nonobese healthcare workers (HCW).

Prospective observational study.

Tertiary medical center.

Healthcare workers.

Baseline influenza antibody titers for obese and nonobese HCW were recorded during the hospital’s 2011 annual influenza vaccination day and follow-up antibody titers were measured 4 weeks later. Antibodies were measured using the hemagglutination inhibition assay and functionality was measured using the micro-neutralization method.

Of 200 initial HCWs, 190 completed the study (97 obese and 93 nonobese). Seroprotection after immunization was not significantly different for nonobese compared with obese HCW for each strain (influenza A [H1N1], 99% and 99%; influenza A [H3N2], 100% and 99%; and influenza B, 67% and 71%, respectively)

All geometric mean titers measured by micro-neutralization showed statistically significant increases in activity. In comparison, there was no difference in the 4-fold increase in H1N1 or B titers. There was a significant difference in the 4-fold increase of H3N2 titers between the nonobese and obese HCWs (82/93 [88%] vs 64/97 [66%], P=.003)

In an ad hoc analysis we found that obese HCWs had a statistically greater number of 4-fold decreases in titers with H1N1 and H3N2.

There was no significant difference in protection from influenza between obese and nonobese HCWs after immunization.

Infect Control Hosp Epidemiol 2014;00(0): 1–5

Contact patterns and microbiological data contribute to a detailed understanding of infectious disease transmission. We explored the automated collection of high-resolution contact data by wearable sensors combined with virological data to investigate influenza transmission among patients and healthcare workers in a geriatric unit.

Proof-of-concept observational study. Detailed information on contact patterns were collected by wearable sensors over 12 days. Systematic nasopharyngeal swabs were taken, analyzed for influenza A and B viruses by real-time polymerase chain reaction, and cultured for phylogenetic analysis.

An acute-care geriatric unit in a tertiary care hospital.

Patients, nurses, and medical doctors.

A total of 18,765 contacts were recorded among 37 patients, 32 nurses, and 15 medical doctors. Most contacts occurred between nurses or between a nurse and a patient. Fifteen individuals had influenza A (H3N2). Among these, 11 study participants were positive at the beginning of the study or at admission, and 3 patients and 1 nurse acquired laboratory-confirmed influenza during the study. Infectious medical doctors and nurses were identified as potential sources of hospital-acquired influenza (HA-Flu) for patients, and infectious patients were identified as likely sources for nurses. Only 1 potential transmission between nurses was observed.

Combining high-resolution contact data and virological data allowed us to identify a potential transmission route in each possible case of HA-Flu. This promising method should be applied for longer periods in larger populations, with more complete use of phylogenetic analyses, for a better understanding of influenza transmission dynamics in a hospital setting.

Infect Control Hosp Epidemiol 2015;00(0): 1–7

To describe the use of antimicrobial stewardship policies and to investigate factors associated with implementation in a national sample of acute care hospitals.

Cross-sectional survey.

Infection Control Directors from acute care hospitals participating in the National Healthcare Safety Network (NHSN).

An online survey was conducted in the Fall of 2011. A subset of hospitals also provided access to their 2011 NHSN annual survey data.

Responses were received from 1,015 hospitals (30% response rate). The majority of hospitals (64%) reported the presence of a policy; use of antibiograms and antimicrobial restriction policies were most frequently utilized (83% and 65%, respectively). Respondents from larger, urban, teaching hospitals and those that are part of a system that shares resources were more likely to report a policy in place (P<.01). Hospitals located in California were more likely to have policy in place than in hospitals located in other states (P=.014).

This study provides a snapshot of the implementation of antimicrobial stewardship policies in place in U.S. hospitals and suggests that statewide efforts in California are achieving their intended effect. Further research is needed to identify factors that foster the adoption of these policies.

Infect Control Hosp Epidemiol 2014;00(0): 1–4

Procalcitonin has emerged as a promising biomarker of bacterial infection. Published literature demonstrates that use of procalcitonin testing and an associated treatment pathway reduces duration of antibiotic therapy without impacting mortality. The objective of this study was to determine the financial impact of utilizing a procalcitonin-guided treatment algorithm in hospitalized patients with sepsis.

Cost-minimization and cost-utility analysis.

Hypothetical cohort of adult ICU patients with suspected bacterial infection and sepsis.

Utilizing published clinical and economic data, a decision analytic model was developed from the U.S. hospital perspective. Effectiveness and utility measures were defined using cost-per-clinical episode and cost per quality-adjusted life years (QALYs). Upper and lower sensitivity ranges were determined for all inputs. Univariate and probabilistic sensitivity analyses assessed the robustness of our model and variables. Incremental cost-effectiveness ratios (ICERs) were calculated and compared to predetermined willingness-to-pay thresholds.

Base-case results predicted the use of a procalcitonin-guided treatment algorithm dominated standard care with improved quality (0.0002 QALYs) and decreased overall treatment costs ($65). The model was sensitive to a number of key variables that had the potential to impact results, including algorithm adherence (<42.3%), number and cost of procalcitonin tests ordered (≥9 and >$46), days of antimicrobial reduction (<1.6 d), incidence of nephrotoxicity and rate of nephrotoxicity reduction.

The combination of procalcitonin testing with an evidence-based treatment algorithm may improve patients’ quality of life while decreasing costs in ICU patients with suspected bacterial infection and sepsis; however, results were highly dependent on a number of variables and assumptions.

Infect Control Hosp Epidemiol 2014;00(0): 1–8

While incidence, mortality, morbidity, and recurrence rates of C. difficile infection (CDI) among the critically ill have been investigated, the impact of its recurrence on 30-day rehospitalization (ReAd), an important policy focus, has not been examined.

Secondary analysis of a multicenter retrospective cohort study

Adult critically ill patients who survived their index hospitalization complicated by CDI

CDI was defined by diarrhea or pseudomembranous colitis and a positive assay for C. difficile toxins A and/or B. CDI recurrence (rCDI) was defined as diarrhea, positive C. difficile toxin and need for retreatment after cessation of therapy. Descriptive statistics and a logistic regression examined ReAd rates and characteristics, and factors that impact it.

Among 287 hospital survivors, 76 (26.5%) required ReAd (ReAd+). At baseline, the ReAd+ group did not differ significantly from the ReAd– group based on demographics, comorbidities, APACHE II scores, or ICU type. ReAd+ patients were more likely to have hypotension at CDI onset (48.7% vs 34.1%, P=.025) and to require vasopressors (40.0% vs 27.1%, P=.038); they were less likely to require mechanical ventilation (56.0% vs 77.3%, P<.001). A far greater proportion of ReAd+ than ReAd– had developed a recurrence either during the index hospitalization or within 30 days after discharge (32.89% vs 2.84%, P<.001). In a logistic regression, rCDI was a strong predictor of ReAd+ (adjusted odd ratio, 15.33, 95% confidence interval, 5.68–41.40).

Greater than 25% of all survivors of critical illness complicated by CDI require readmission within 30 days of discharge. CDI recurrence is a strong predictor of such rehospitalizations.

Infect Control Hosp Epidemiol 2014;00(0): 1–7

Determine whether the NAP1 strain identified by polymerase chain reaction (PCR)-based stool assay is correlated with CDI severity and clinical outcomes.

Medical records of adult patients with positive stool Xpert® Clostridium difficile PCR assay for an initial episode of CDI between January 2012 and January 2013 at a tertiary care hospital in Chicago were reviewed. Two patients diagnosed with CDI caused by a non-NAP1 strain (positive Xpert® C. difficile assay but negative Xpert® C. difficile Epi assay) were included for each patient diagnosed with CDI caused by a NAP1 strain (positive Epi assay). Patient charts were reviewed for markers of severity, risk factors, treatment regimens, and outcomes.

Of 494 stool specimens, 90 (18%) that were positive for C. difficile by PCR were positive for NAP1 strain. In total, 37 patients with CDI due to NAP1 were matched with 74 patients with CDI due to non-NAP1 strains. Multivariable model revealed individuals ≥65 years old were 3 times more likely to have NAP1 strain than individuals <65 (P=.02). Residents of a nursing home prior to hospitalization were 10 times more likely to have NAP1 strain than patients residing in their homes (P=.001). More NAP1 cases had a change in treatment from metronidazole to oral vancomycin plus intravenous metronidazole (P=.01). The severity of CDI, incidence of mortality and recurrent CDI were similar between groups.

In a nonepidemic setting, NAP1 strains were more common in older patients and individuals admitted from nursing homes. Identification of NAP1 by PCR of stool specimens was associated in a change of therapy but did not predict worse outcomes. Reporting strain results may not be clinically useful in routine settings.

Infect Control Hosp Epidemiol 2014;00(0): 1–7

To investigate the impact of 1-week ventilator circuit change on ventilator-associated pneumonia and its cost-effectiveness compared with a 2-day change.

An observational cohort study.

A tertiary level neonatal intensive care unit in a university-affiliated teaching hospital in Taiwan.

All neonates in the neonatal intensive care unit receiving invasive intubation for more than 1 week from July 1, 2011, through December 31, 2013.

We investigated the impact of 2 ventilator circuit change regimens, either every 2 days or 7 days, on ventilator-associated pneumonia of our cohort.

A total of 361 patients were maintained on mechanical ventilators for 13,981 days. The 2 groups did not differ significantly in any demographic characteristics. The rate of ventilator-associated pneumonia was comparable between the 2-day group and the 7-day group (8.2 vs 9.5 per 1,000 ventilator-days, P=.439). The durations of mechanical ventilation and hospital stay, and rates of bloodstream infection and mortality, were also comparable between the 2 groups. Switching from a 2-day to a 7-day change policy would save our neonatal intensive care unit a yearly sum of US $29,350 and 525 working hours.

Decreasing the frequency of ventilator circuit changes from every 2 days to once per week is safe and cost-effective in neonates requiring prolonged intubation for more than 1 week.

Infect Control Hosp Epidemiol 2014;00(0): 1–7

To assess the impact of a novel, silver-coated needleless connectors (NCs) on central-line–associated bloodstream infection (CLABSI) rates compared with a mechanically identical NCs without a silver coating.

Prospective longitudinal observation study

Two 500-bed university hospitals

All hospitalized adults from November 2009 to June 2011 with non-hemodialysis central lines

Hospital A started with silver-coated NCs and switched to standard NCs in September 2010; hospital B started with standard NCs and switched to silver-coated NCs. The primary outcome was the difference revealed by Poisson multivariate regression in CLABSI rate using standard Centers for Disease Control and Prevention surveillance definitions. The secondary outcome was a comparison of organism-specific CLABSI rates by NC type.

Among 15,845 hospital admissions, 140,186 central-line days and 221 CLABSIs were recorded during the study period. In a multivariate model, the CLABSI rate per 1,000 central-line days was lower with silver-coated NCs than with standard NCs (1.21 vs 1.79; incidence rate ratio=0.68 [95% CI: 0.52–0.89], P=.005). A lower CLABSI rate per 1,000 central-line days for the silver-coated NCs versus the standard NCs was observed with S. aureus (0.11 vs 0.30, P=.02), enterococci (0.10 vs 0.27, P=.03), and Gram-negative organisms (0.28 vs 0.63, P=.003) but not with coagulase-negative staphylococci (0.31 vs 0.36) or Candida spp. (0.42 vs 0.40).

The use of silver-coated NCs decreased the CLABSI rate by 32%. CLABSI reduction efforts should include efforts to minimize contamination of NCs.

Infect Control Hosp Epidemiol 2014;00(0): 1–8

According to the World Health Organization guidelines, field tests, in the context of a bid for the supply of alcohol-based hand rubs, should take into account climatic region, test period, products already in use, and type of use (hygienic or surgical) when assessing tolerance. This laborious method is often contested.

To conduct a post hoc analysis of the data of a large bid, including 5 factors, to validate the relevance of their inclusion.

For the purposes of the bid, products were compared in terms of the 4 World Health Organization tolerance criteria (appearance, intactness, moisture content, sensation) during product testing and were separated into groups on the basis of the studied factors. The post hoc analysis method included (1) comparison of the mean before-and-after difference based on the self-evaluation of the skin with the 4 World Health Organization tolerance criteria, between climatic regions, periods, products in use, test product, and the type of use; (2) generalized linear models, taking into account all studied factors.

The analysis included data for 1,925 pairs of professionals. The means of the differences observed were independently and significantly associated with the test period (P<.001), the hygienic or surgical use (P=.010 to .041, not significant for appearance), the product already in use (significant for appearance P=.021), and the test product (P<.001). The association with climatic region was found to be significant only in the nonadjusted analysis.

The type of use, the test period, and the product in use should be taken into account when designing field tests of alcohol-based hand rubs.

Infect Control Hosp Epidemiol 2014;00(0): 1–9

To compare Pseudomonas aeruginosa prevalence in electronic and manual faucets and assess the influence of connecting pipes and water quality.

Faucets in 4 healthcare centers in Quebec, Canada.

Water samples from 105 electronic, 90 manual, and 14 foot-operated faucets were analyzed for P. aeruginosa by culture and enzymatic detection, and swab samples from drains and aerators were analyzed by culture. Copper and residual chlorine concentrations, temperature, and flow rate were measured. P. aeruginosa concentrations were analyzed in 4 consecutive volumes of cold water and a laboratory study was conducted on copper pipes and flexible hoses.

P. aeruginosa contamination was found in drains more frequently (51%) than in aerators (1%) or water (culture: 4%, enzyme detection: 16%). Prevalence in water samples was comparable between manual (14%) and 2 types of electronic faucets (16%) while higher for foot-operated faucets (29%). However, type 2 electronic faucets were more often contaminated (31%) than type 1 (14%), suggesting that faucet architecture and mitigated volume (30 mL vs 10 mL) influence P. aeruginosa growth. Concentrations were 100 times higher in the first 250 mL than after flushing. Flexible hoses were more favorable to P. aeruginosa growth than copper and a temperature of 40°C led to higher counts.

The types of faucets and connecting pipes, flow rate, and water quality are important parameters influencing the prevalence and the concentrations of P. aeruginosa in faucets. High concentrations of P. aeruginosa in the first 250 mL suggest increased risk of exposure when using the first flush.

Infect Control Hosp Epidemiol 2014;00(0): 1–9

Immunocompromised patients now benefit from a longer life expectancy due to advanced medical techniques, but they are also weakened by aggressive treatment approaches and are at high risk for invasive fungal disease. We determined risk factors associated with an outbreak of invasive filamentous fungal infection (IFFI) among hospitalized hemato-oncological patients.

A retrospective, matched, case-control study was conducted between January 1, 2009, and April 31, 2011, including 29 cases (6 proven, 8 probable, and 15 possible) of IFFI and 102 matched control patients hospitalized during the same time period. Control patients were identified from the hospital electronic database. Conditional logistic regression was performed to identify independent risk factors for IFFI.

Overall mortality associated with IFFI was 20.7% (8.0%–39.7%). Myelodysplastic syndrome was associated with a higher risk for IFFI compared to chronic hematological malignancies. After adjustment for major risk factors and confounders, >5 patient transfers outside the protected environment of the hematology ward increased the IFFI risk by 6.1-fold. The risk increased by 6.7-fold when transfers were performed during neutropenia.

This IFFI outbreak was characterized by a strong association with exposure to the unprotected environment outside the hematology ward during patient transfer. The independent associations of a high number of transfers with the presence of neutropenia suggest that affected patients were probably not sufficiently protected during transport in the corridors. Our study highlights that a heightened awareness of the need for preventive measures during the entire care process of at-risk patients should be promoted among healthcare workers.

Infect Control Hosp Epidemiol 2014;00(0): 1–9

To investigate whether operative factors are associated with risk of surgical site infection (SSI) after hernia repair.

Retrospective cohort study.

Commercially insured enrollees aged 6 months-64 years with International Classification of Diseases, Ninth Revision, Clinical Modification procedure or Current Procedural Terminology, fourth edition, codes for inguinal/femoral, umbilical, and incisional/ventral hernia repair procedures from January 1, 2004, through December 31, 2010.

SSIs within 90 days after hernia repair were identified by diagnosis codes. The χ2 and Fisher exact tests were used to compare SSI incidence by operative factors.

A total of 119,973 hernia repair procedures were analyzed. The incidence of SSI differed significantly by anatomic site, with rates of 0.45% (352/77,666) for inguinal/femoral, 1.16% (288/24,917) for umbilical, and 4.11% (715/17,390) for incisional/ventral hernia repair. Within anatomic sites, the incidence of SSI was significantly higher for open versus laparoscopic inguinal/femoral (0.48% [295/61,142] vs 0.34% [57/16,524], P=.020) and incisional/ventral (4.20% [701/16,699] vs 2.03% [14/691], P=.005) hernia repairs. The rate of SSI was higher following procedures with bowel obstruction/necrosis than procedures without obstruction/necrosis for open inguinal/femoral (0.89% [48/5,422] vs 0.44% [247/55,720], P<.001) and umbilical (1.57% [131/8,355] vs 0.95% [157/16,562], P<.001), but not incisional/ventral hernia repair (4.01% [224/5,585] vs 4.16% [491/11,805], P=.645).

The incidence of SSI was highest after open procedures, incisional/ventral repairs, and hernia repairs with bowel obstruction/necrosis. Stratification of hernia repair SSI rates by some operative factors may facilitate accurate comparison of SSI rates between facilities.

Infect Control Hosp Epidemiol 2014;00(0): 1–7