Teresa Zembower

Northwestern Memorial Hospital, Chicago, Illinois, United States

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Publications (58)192.6 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: The hospital environment poses a substantial risk for transmission of pathogens. Assessing cleaning efficacy is difficult and often relies on a subjective visual check. A multidisciplinary approach is required to evaluate and improve hospital cleanliness. However, an objective, reliable quality indicator is needed as an outcome metric to assess the cleanliness of the environment. Technology is available to detect adenosine triphosphate (ATP), a substance present in organic matter, which can generate a measure of cleanliness. Methods: From August 2013-March 2014, we swabbed 30 discharge-cleaned rooms per week using the ATP technology in six nursing units, selected based on historical multi-drug-resistant organism (MDRO) transmission data. Up to 17 high-touch surfaces were sampled per room. The 3M Clean-Trace luminometerTM quantifies organic material on each surface. A reading below 250 RLU is considered a clean surface. If more than 30% of surfaces per room fail, recleaning is required. Metrics included: percentage of surfaces that fail, room fail rate, percent fails by surface, percent fails by unit, room fail rate, and MDRO transmission in relation to surface fails. Nursing, Infection Prevention, and Environmental Services management were responsible to test rooms. The data were used to formulate intervention strategies. Results: Weekly data showed an improvement over time trending towards the goal of 90% (figure 1) Over eight months, the average monthly clean surface rate increased from 77% pre-intervention to 84% post-intervention (figure 2). We also saw a relationship between multi-drug resistant organism (MDRO) transmission and room cleanliness (figure 3.). Intervention strategies included retraining EVS staff on appropriate cleaning practices, posting pictures of high-touch surfaces, distributing a fact of the week, weekly data feedback, and performing real-time ATP process with the EVS staff that cleaned the room. Conclusion: The ability to assess cleaning performance with an objective, reliable metric, and analyze the data by individual touch point and staff accountability, led to improved cleanliness, reduced MDRO transmission risk, and enhanced collaboration efforts among Nursing, IP and EVS.
    IDWeek 2014 Meeting of the Infectious Diseases Society of America; 10/2014
  • Daniel P. Boyle, Teresa R. Zembower, Chao Qi
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    ABSTRACT: We evaluated the ability of the Vitek MS system to classify clinical pulmonary Mycobacterium avium complex isolates compared to Multilocus Sequence Analysis (MLSA). Vitek MS accurately identified 55% of the isolates as M. avium and 18% as M. intracellulare, but misidentified 24 (27%) M. chimaera isolates as M. intracellulare.
    Diagnostic Microbiology and Infectious Disease. 10/2014;
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    ABSTRACT: Institution of appropriate airborne infection isolation (AII) precautions for patients with suspected Mycobacterium tuberculosis is critical to prevent disease transmission. We compared the yield of acid-fast bacilli smears from different types of respiratory specimens and found that smear sensitivity was highest for specimens obtained by endotracheal aspirates (92%), followed by sputum (79%), and then by bronchoalveolar lavage (37%). As a result of this study, our institutional policy regarding discontinuation of AII precautions was amended.
    American Journal of Infection Control. 09/2014;
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    ABSTRACT: Optimal surveillance strategies for identifying patients colonized with and at risk for transmitting carbapenem-resistant Enterobacteriaceae (CRE) are urgently needed. We instituted an enhanced surveillance program for CRE that identified unrecognized CRE-colonized patients but failed to identify possible CRE transmissions. We also identified risk factors associated with transmitting CRE.
    Infection Control and Hospital Epidemiology 04/2014; 35(4):419-22. · 4.02 Impact Factor
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    ABSTRACT: Clinical studies have suggested that blaOXA-40-positive A. baumannii isolates are associated with poor patient outcomes; however, reasons for unfavorable outcomes are difficult to discern in clinical studies. The objective of this study was to assess the virulence of carbapenem-resistant A. baumannii according to blaOXA-40and epidemiological outbreak status in a Galleria mellonella model. Eight isolates of A. baumannii were studied. Non-outbreak isolates and blaOXA-40-negative isolates caused more rapid fatality of infected G. mellonella (p<0.01).
    Antimicrobial Agents and Chemotherapy 12/2013; · 4.57 Impact Factor
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    ABSTRACT: Assessing clinical virulence differences between vancomycin-resistant Enterococcus faecium (VREF) resistant to linezolid (LRVRE) and to linezolid susceptible VREF (LSVRE) is difficult due to confounding patient variables. Galleria mellonella is a validated host-interaction model allowing for straight forward organism virulence assessment. The objectives of this study were to assess the virulence of VREF in G. mellonella according to linezolid resistance and clinical outbreak status. A genetically related pair of VREF strains with and without genotypically confirmed linezolid resistance was selected for analysis. Additionally, six strains of LSVRE and two strains of LRVRE were selected according to epidemiologic outbreak status. Mortality of G. mellonella was assessed daily over a five day period and analyzed using Kaplan-Meier survival curves and log rank tests. Linezolid resistance did not have a significant effect on G. mellonella mortality in the genetically related pair (p=0.93). There was no significant difference in mortality over time between outbreak strains (non-outbreak (n=2) vs. outbreak (n=6), p=0.84; extensive (n=2) vs. limited (n=4), p=0.78). These results suggest that patients infected with LRVRE or outbreak strains of VREF are at no greater risk of poor outcomes mediated by organism virulence than those infected with LSVRE or non-outbreak strains.
    Antimicrobial Agents and Chemotherapy 06/2013; · 4.57 Impact Factor
  • American Journal of Infection Control 06/2013; 41(6):S23. · 2.73 Impact Factor
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    ABSTRACT: Purpose We determine the prevalence of ciprofloxacin resistant gram-negative bacilli in patients scheduled for transrectal ultrasound guided prostate biopsy, characterize the Escherichia coli strains recovered from this patient population, and characterize the mechanisms responsible for β-lactam and ciprofloxacin resistance. Materials and Methods Rectal swabs from 991 patients were cultured for ciprofloxacin resistant gram-negative bacilli with a selective medium. Recovered E. coli isolates were further analyzed with susceptibility testing, pulsed field gel electrophoresis, plasmid isolation and sequencing. Results A total of 193 ciprofloxacin resistant gram-negative bacilli were recovered and of these isolates 167 (87%) were E. coli. The prevalence of ciprofloxacin resistant E. coli in the study population was 17%. Only 38 (26%) of the 149 E. coli isolates that received susceptibility testing were susceptible to ampicillin and ampicillin-sulbactam. In select isolates transferrable plasmids carrying β-lactamase were responsible for the resistance to the β-lactam agents and other nonβ-lactam antimicrobials. Diverse combinations of gyrA and parC mutations associated with fluoroquinolone resistance were identified. Strain typing and plasmid typing indicated that the E. coli isolates did not share a common origin. Conclusions Of the patients in our study 17% carried ciprofloxacin resistant E. coli. Analysis of resistance mechanisms and plasmid analysis along with strain typing demonstrated that this patient population harbored organisms with heterogeneous phenotypic susceptibility, indicating that universal prophylaxis would not provide optimal coverage for patients undergoing transrectal ultrasound guided prostate biopsy.
    The Journal of urology 01/2013; 190(6):2026–2032. · 3.75 Impact Factor
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    ABSTRACT: BACKGROUND: Patients are often screened with surveillance cultures to discern transmissions vs transformation of an isolate to vancomycin-resistant Enterococcus faecium. To determine the amount of time between which isolates could be considered genetically similar by pulsed-field gel electrophoresis, isolate change over time within single patients was studied. METHODS: A minimum of 4 isolates per patient, separated by at least 2 months, were collected from previously frozen stores. Visual comparison of banding patterns was conducted, and percent relatedness was calculated. RESULTS: Twenty-eight isolates from 6 patients were studied. No isolate differed by more than 3 bands before 150 days, and the average percent difference per band was 3.7%. The isolates diverged genetically as a linear function of number of bands over time (good model fit intrapatient r(2) = 0.42; poor model fit interpatient r(2) = 0.0062). CONCLUSION: Trajectory of genetic variation appears to be isolate/patient specific; however, commonalities exist and tested isolates were relatively stable out to 150 days.
    American journal of infection control 10/2012; · 3.01 Impact Factor
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    ABSTRACT: Antimicrobial drug shortages continue to increase, with few new therapeutic options available. Nationally, proposals have been offered to alleviate drug shortages; however, these recommendations are unlikely to effect change in the near future. Thus, antimicrobial stewardship leaders in acute care hospitals must develop a prospective management strategy to lessen the impact of these shortages on patient care. Herein, we describe several resources available to aid professionals in antimicrobial stewardship and healthcare epidemiology to manage drug shortages. An effective approach should include prospectively tracking shortages and maximizing inventory by appropriately managing usage. Several tenets should underpin this management. Alternative agents should be rationally chosen before the inventory of the primary agent has reached zero, ethical considerations should be taken into account, and timely notification and communication with key stakeholders should occur throughout the prescribing and dispensing process.
    Infection Control and Hospital Epidemiology 07/2012; 33(7):745-52. · 4.02 Impact Factor
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    ABSTRACT: The emergence of the pandemic H1N1 influenza strain in 2009 reinforced the need for improved influenza surveillance efforts. A previously described influenza typing assay that utilizes RT-PCR coupled to electro-spray ionization mass spectrometry (ESI-MS) played an early role in the discovery of the pandemic H1N1 influenza strain, and has potential application for monitoring viral genetic diversity in ongoing influenza surveillance efforts. To determine the analytical sensitivity of RT-PCR/ESI-MS influenza typing assay for identifying the pandemic H1N1 strain and describe its ability to assess viral genetic diversity. Two sets of pandemic H1N1 samples, 190 collected between April and June of 2009, and 69 collected between October 2009 and January 2010, were processed by the RT-PCR/ESI-MS influenza typing assay, and the spectral results were compared to reference laboratory results and historical sequencing data from the Nucleotide Database of the National Center for Biotechnology Information (NCBI). Strain typing concordance with reference standard testing was 100% in both sample sets, and the assay demonstrated a significant increase in influenza genetic diversity, from 10.5% non-wildtype genotypes in early samples to 69.9% in late samples (P<0.001). An NCBI search demonstrated a similar increase, from 13.4% to 45.2% (P<0.001). This comparison of early versus late influenza samples analyzed by RT-PCR/ESI-MS demonstrates the influenza typing assay's ability as a universal influenza detection platform to provide high-fidelity pH1N1 strain identification over time, despite increasing genetic diversity in the circulating virus. The genotyping data can also be leveraged for high-throughput influenza surveillance.
    Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 06/2012; 54(4):332-6. · 3.12 Impact Factor
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    ABSTRACT: Anti-infective shortages pose significant logistical and clinical challenges to hospitals and may be considered a public health emergency. Anti-infectives often represent irreplaceable life-saving treatments. Furthermore, few new agents are available to treat increasingly prevalent multidrug-resistant pathogens. Frequent anti-infective shortages have substantially altered patient care and may lead to inferior patient outcomes. Because many of the shortages stem from problems with manufacturing and distribution, federal legislation has been introduced but not yet enacted to provide oversight for the adequate supply of critical medications. At the local level, hospitals should develop strategies to anticipate the impact and extent of shortages, to identify therapeutic alternatives, and to mitigate potential adverse outcomes. Here we describe the scope of recent anti-infective shortages in the United States and explore the reasons for inadequate drug supply.
    Clinical Infectious Diseases 03/2012; 54(5):684-91. · 9.37 Impact Factor
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    ABSTRACT: We evaluated targeted antimicrobial prophylaxis in men undergoing transrectal ultrasound guided prostate biopsy based on rectal swab culture results. From July 2010 to March 2011 we studied differences in infectious complications in men who received targeted vs standard empirical ciprofloxacin prophylaxis before transrectal ultrasound guided prostate biopsy. Targeted prophylaxis used rectal swab cultures plated on selective media containing ciprofloxacin to identify fluoroquinolone resistant bacteria. Patients with fluoroquinolone susceptible organisms received ciprofloxacin while those with fluoroquinolone resistant organisms received directed antimicrobial prophylaxis. We identified men with infectious complications within 30 days after transrectal ultrasound guided prostate biopsy using the electronic medical record. A total of 457 men underwent transrectal ultrasound guided prostate biopsy, and of these men 112 (24.5%) had rectal swab obtained while 345 (75.5%) did not. Among those who received targeted prophylaxis 22 (19.6%) men had fluoroquinolone resistant organisms. There were no infectious complications in the 112 men who received targeted antimicrobial prophylaxis, while there were 9 cases (including 1 of sepsis) among the 345 on empirical therapy (p=0.12). Fluoroquinolone resistant organisms caused 7 of these infections. The total cost of managing infectious complications in patients in the empirical group was $13,219. The calculated cost of targeted vs empirical prophylaxis per 100 men undergoing transrectal ultrasound guided prostate biopsy was $1,346 vs $5,598, respectively. Cost-effectiveness analysis revealed that targeted prophylaxis yielded a cost savings of $4,499 per post-transrectal ultrasound guided prostate biopsy infectious complication averted. Per estimation, 38 men would need to undergo rectal swab before transrectal ultrasound guided prostate biopsy to prevent 1 infectious complication. Targeted antimicrobial prophylaxis was associated with a notable decrease in the incidence of infectious complications after transrectal ultrasound guided prostate biopsy caused by fluoroquinolone resistant organisms as well as a decrease in the overall cost of care.
    The Journal of urology 02/2012; 187(4):1275-9. · 3.75 Impact Factor
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    ABSTRACT: Reducing the incidence of hospital-acquired pneumonia (PNU) is important but depends on accurate assessment. We sought to determine the interrater reliability of diagnosis of PNU and its impact on resource utilization and functional outcomes in a high-risk population. Patients admitted in 2007 with intracranial hemorrhage were prospectively identified. Pneumonia was prospectively diagnosed by Centers for Disease Control criteria by a neurointensivist and infection control. An independent retrospective determination was made by a fellow, an infectious disease attending physician, and a pulmonologist after review of the electronic medical records and radiographs. Interrater reliability was analyzed with κ statistics. One and 3-month outcomes were measured with the modified Rankin scale. Of 103 patients, the incidence of PNU ranged from 5% to 25%. Interrater reliability was poor (median κ = 0.30 [0.19-0.42]; P < .001). Any ascertainment of PNU was associated with longer intensive care unit length of stay, more fever and ventilator dependence, and worse functional outcomes. Pneumonia had poor interrater reliability despite highly trained reviewers and validated criteria. Although the clinical assessment of PNU is difficult, it was associated with greater resource use and worse outcomes. Diagnosis of clinical PNU may be suboptimal for measuring quality of intensive care.
    Journal of critical care 01/2012; 27(5):527.e7-527.e11. · 2.13 Impact Factor
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    ABSTRACT: Background: Blood culture results that become available after hospital discharge are at risk of being overlooked. The frequency and significance of these incidents are unknown. In this prospective interventional project, the ASP sought to identify, evaluate and intervene on cases of recently-discharged patients with missed positive blood cultures. Methods: This interventional project was conducted to review all positive blood cultures finalized within 7 days of hospital discharge. Blood culture review was facilitated by use of an electronic decision support program. The study was conducted over a 29-week period between October 1, 2010 and April 15, 2011. For cases requiring intervention, the ASP member contacted a responsible clinician in order to formulate a therapeutic and/or diagnostic plan. Results of the intervention and a judgment of critical or non-critical were documented. Results: During the study period, 209 recently-discharged patients were reviewed. Of these, 39 cases (19%) required intervention. Ten (5%) required non-critical interventions; whereas, 29 (14%) required critical interventions. Critical interventions included changing antibiotics, drawing additional blood cultures, removing central lines, performing echocardiography and readmitting patients. Eight cases (20%) required extensive coordination with our Emergency Department or outside institutions. Gram-positive organisms predominated (n=19, 49%), of which 9 (23%) were Staphylococcus aureus, followed by gram negative bacteria (n=11, 28%), fungi (n=5, 13%), anaerobes (n= 4, 10%) and mycobacteria (n=2, 5%); some patients had more than one isolate. Conclusion: At our institution, missed bloodstream infections at or near discharge is a previously unrecognized, wide-spread problem. Thought should be given to expanding the role of ASPs to address this patient safety issue.
    Infectious Diseases Society of America 2011 Annual Meeting; 10/2011
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    ABSTRACT: Immunochromatographic urine pneumococcal antigen testing (ICT) has become a common diagnostic tool for those presenting with possible invasive pneumococcal disease. The incidence and clinical impact of ICT false-positivity on hospitalized patients has not been assessed outside of specific patient subpopulations. ICT performance needs to be assessed in a real-world clinical setting. This study aims to describe the incidence and clinical impact of ICT false-positivity in a hospital setting over a 19-month period. A retrospective cohort study was performed to assess the incidence of false-positive (FP) ICT among hospitalized patients from November 21, 2007 to June 30, 2009. The primary objective was to describe the incidence of FP ICT results. The secondary objective was to describe what clinical impact, if any, could be attributed to FP ICT results. During the study period, 52 positive ICT results were obtained, of which 5 (9.6%) were deemed falsely positive. Interestingly, two of the 5 FP results were from patients who had received 23-valent pneumococcal vaccine (PPV) in the 2 days prior to ICT. The management of all 5 patients was impacted by the FP results through unnecessary antimicrobial treatment and/or deferral of further clinical evaluation. Health care providers should be aware of the potential for ICT FP and should order and interpret these tests within an informed clinical framework.
    Southern medical journal 08/2011; 104(8):593-7. · 0.92 Impact Factor
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    ABSTRACT: A 55-y-old woman with no previous medical history presented with a 3-day history of progressive headache, nausea, emesis, right-sided facial numbness, and right-sided extremity weakness. Serial magnetic resonance imaging demonstrated rapid enlargement of a left-sided ring-enhancing dorsal pontine lesion with an exophytic portion, raising concern for an abscess. A stereotactically guided left-sided retrosigmoid craniotomy for abscess incision and decompression was performed given the rapid progression of her neurological deficits. Streptococcus salivarius was isolated from the intra-operative samples. After an extensive evaluation, no source for the S. salivarius was identified. Solitary brainstem abscesses are uncommon intracranial infections with high morbidity and mortality. Patients can present with non-specific symptoms and often have no previous medical history. Since 1974, 40 patients with solitary brainstem abscess have survived to hospital discharge. We outline management strategies for solitary brainstem abscess based on a literature review of survivors.
    Scandinavian Journal of Infectious Diseases 07/2011; 43(11-12):837-47. · 1.71 Impact Factor
  • Journal of Urology - J UROL. 01/2011; 185(4).
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    ABSTRACT: Background: Preventing transmission of 2009 H1N1 influenza (nH1N1) within the healthcare setting has been a major focus of infection control (IC) programs in the wake of the pandemic. Hierarchies of control include elimination of potential exposures, engineering controls, administrative controls, and personal protective equipment (PPE). Study of factors leading to exposure can inform future measures for prevention of transmission of droplet-borne infections. Objective: To analyze the extent and cause of documented exposures to nH1N1 occurring at one U.S. medical center during the early part of the pandemic. Methods: During the study period, all individuals with unprotected close contact with a probable or confirmed case of nH1N1 were identified by IC personnel, entered into an electronic database, and referred for further evaluation. Data were analyzed to determine the number and role of individuals affected by exposure, clinical areas affected by exposures, and the apparent cause of the exposure. Results: From April 29th to August 31st 2009, 1218 individuals had unprotected exposure to nH1N1 at our institution; including, 1168 healthcare workers (HCW) (96%), 46 patients, and 4 visitors. Over this same period, a total of 239 cases of probable or confirmed nH1N1 influenza were cared for (49 inpatients, 190 outpatients or emergency department (ED)). A total of 47 exposure events occurred; the median number of individuals exposed per event was 9, the range 0 to 138. The majority of exposures occurred in the ED (33%), the general medicine floors (21%), or the intensive care units (16%). Among HCW, the job types most likely to be exposed included: nurses (42% of exposures), physicians (18%), respiratory therapists (8%), and radiology technicians (7%). While the median duration of exposure was 1 day, the range was < 1 to 9 days. Infected patients were the source of 36 exposure events (77%), while infected HCW were the source in 11 (23%). The total number of individuals exposed by an infected patient was 1012 (70%) vs. 206 (30%) exposed by a HCW. The median size of exposure events caused by patients and HCW was similar (9.5 vs. 8 individuals exposed, respectively). In 43 exposure events, IC documentation indicated a likely explanation for the exposure: 22 were due to a delay in initiation of isolation; 9 were due to a HCW working while ill; 5 were due to late clinical recognition of influenza; 4 were due to failure to implement precautions appropriately; 3 were due to inaccurate test results. Conclusions: The burden of potential exposures to nH1N1 during the early part of the pandemic was high, particularly as many of these individuals were offered chemoprophylaxis during this timeframe. This evaluation reveals a failure of several IC hierarchies, which can inform prevention efforts targeted to the clinical areas and HCW roles most likely to be affected by influenza exposures.
    Fifth Decennial International Conference on Health-Care Related Infections 2010; 03/2010
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    ABSTRACT: Background: Infection prevention and control is vital to the safety of workers in the healthcare setting. Prevention measures include isolation precautions to prevent exposure to infectious agents and immunization for vaccine preventable diseases. Despite these measures, occupational exposures still occur and post-exposure evaluations are necessary. The exposure management process is both time and labor intensive. In order to prevent transmissions, exposed healthcare workers (HCWs) must comply with the post-exposure process. However, HCWs do not always comply making the work-up more burdensome and increasing the risk of secondary exposures. New electronic technology makes it possible to streamline the process and track exposures, thus increasing compliance. In response to an exposure event at a large urban academic medical center in 2006 involving 339 individuals (325 HCWs and 14 close contacts), at least 12 departments, and an estimated $262,788 in costs, a multidisciplinary team (MDT) convened to design and implement an electronic system to serve as an infectious diseases exposure event tracking system and a central data repository for employee health information. Objective: Improve the process of identifying, managing and tracking HCWs exposed to communicable infectious diseases and streamline the time and resources involved. Methods: Employee vaccination records were manually transferred from paper charts to a secure, web-based electronic system. In the event of an exposure, the system identifies HCWs considered susceptible to the infectious disease while excluding HCWs recognized as being immune based on a customized set of rules developed by the MDT. Managers of departments involved in the exposure receive immediate electronic notification of susceptible employees and then determine which HCWs meet the exposure criteria established by the Infection Control and Prevention Department (IC). Only HCWs who are susceptible and exposed require medical evaluation. Post-exposure evaluation dispositions are available electronically and in real-time. Follow-up and management of delinquent HCWs are tracked and managed electronically. Results: Compared with the 24 months prior to the implementation of an electronic system, employee compliance with post-exposure evaluation has increased as follows: varicella from 30% to 100%, baseline Mycobacterium tuberculosis (MTB) from 50% to 100%, 10 week MTB follow-up from 5% to 30%. Time needed by IC to track and manage communicable infectious disease exposure events was reduced by an estimated 50%. Conclusions: Appropriate management of HCWs exposed to infectious agents is critical for an organization. The use of an electronic system expedites recognition of exposed HCWs, facilitates post-exposure evaluation and targets prevention of further transmissions. These electronic systems improve time and resource utilization.
    Fifth Decennial International Conference on Health-Care Related Infections 2010; 03/2010

Publication Stats

708 Citations
192.60 Total Impact Points


  • 1998–2014
    • Northwestern Memorial Hospital
      • Department of Pharmacy
      Chicago, Illinois, United States
  • 2013
    • Chicago State University
      • Department of Pharmacy Practice
      Chicago, Illinois, United States
    • Midwestern University
      Glendale, Arizona, United States
  • 2005–2013
    • Northwestern University
      • • Department of Pathology
      • • Division of Infectious Diseases (Dept. of Medicine)
      • • Feinberg School of Medicine
      Evanston, IL, United States
  • 2005–2012
    • University of Illinois at Chicago
      • • Department of Pharmacy Practice
      • • Section of Infectious Diseases
      Chicago, IL, United States