Sources of viral respiratory infections in Canadian acute care hospital healthcare personnel.

BACKGROUND: Viral respiratory illnesses are common causes of outbreaks and can be fatal to some patients. AIM: To investigate the association between laboratory-confirmed viral respiratory infections and potential sources of exposure during the previous 7 days. METHODS: In this nested case-control analysis, healthcare personnel from nine Canadian hospitals who developed acute respiratory illnesses during the winters of 2010/11-2013/14 submitted swabs that were tested for viral pathogens. Associated illness diaries and the weekly diaries of non-ill participants provided information on contact with people displaying symptoms of acute respiratory illness in the previous week. Conditional logistic regression assessed the association between cases, who were matched by study week and site with controls with no respiratory symptoms. FINDINGS: There were 814 laboratory-confirmed viral respiratory illnesses. The adjusted odds ratio (aOR) of a viral illness was higher for healthcare personnel reporting exposures to ill household members [7.0, 95% confidence interval (CI) 5.4-9.1], co-workers (3.4, 95% CI 2.4-4.7) or other social contacts (5.1, 95% CI 3.6-7.1). Exposures to patients with respiratory illness were not associated with infection (aOR 0.9, 95% CI 0.7-1.2); however, healthcare personnel with direct patient contact did have higher odds (aOR 1.3, 95% CI 1.1-1.6). The aORs for exposure and for direct patient contact were similar for illnesses caused by influenza. CONCLUSION: Community and co-worker contacts are important sources of viral respiratory illness in healthcare personnel, while exposure to patients with recognized respiratory infections is not associated. The comparatively low risk associated with direct patient contact may reflect transmission related to asymptomatic patients or unrecognized infections.

Immunogenicity and reactogenicity of high- vs. standard-dose trivalent inactivated influenza vaccine in healthcare workers: a pilot randomized controlled trial.

OBJECTIVES: To compare immunogenicity, reactogenicity and acceptability of high- and standard-dose trivalent inactivated influenza vaccine (HDTIV, SDTIV) in 18- to 64-year-olds. METHODS: We randomized 18- to 64-year-olds to HDTIV or SDTIV in two consecutive years. We collected serum on days 0 and 21, measured haemagglutination inhibition geometric mean titres (GMT) and compared seroconversion, day 21 titres, seroprotection, reactogenicity and acceptability. RESULTS: Immunogenicity was evaluable in 42 of 47 2014 participants, all 33 both-year participants and 87 of 90 2015-only participants. First-dose HDTIV recipients experienced seroconversion more frequently than SDTIV recipients to A(H3N2) in 2014 (13/21, 62% vs. 4/21, 19%, p 0.01) and to all vaccine strains in 2015: (A(H1N1): 24/42, 57% vs. 15/59, 25%; A(H3N2): 42/42, 100% vs. 47/59, 80%; B: 25/42, 60% vs. 13/59, 22%; all p <0.01). Day 21 haemagglutination inhibition GMT were higher in first and two sequential-year HDTIV vs. SDTIV recipients: A(H1N1): GMT 749 and 768 vs. 384 (p <0.0001, p 0.002); A(H3N2): 1238 and 956 vs. 633 (p 0.0003, p 0.1); and B: 1113 and 1086 vs. 556 (p 0.0005, p 0.02). HDTIV was more reactogenic (local pain score 3 vs. 1 of 10 on day 0/1, p 0.0003), but recipients were equally willing to be revaccinated (HDTIV: 76/83 (92%); SDTIV: 76/80 (95%), p 0.54). The ratios of day 21 GMT in SDTIV recipients vaccinated in 0 to 4 prior years to those in SDTIV and HDTIV recipients vaccinated in 15 or more prior years were A(H1N1): 3.73 and 1.38; A(H3N2) 3.07 and 1.16; and B: 2.01 and 1.21. CONCLUSIONS: HDTIV is more immunogenic and reactogenic and as acceptable as SDTIV in 18- to 64-year-olds.

Susceptibilities of clinical Clostridium difficile isolates to antimicrobials: a systematic review and meta-analysis of studies since 1970.

OBJECTIVES: Although exposure to antibiotics can cause Clostridium difficile infection, certain antibiotics are used to treat C. difficile. Measurements of antimicrobial C. difficile activity could help to identify antibiotic risk and emergent resistance. Here, we describe publication patterns relating to C. difficile susceptibilities and estimate minimum inhibitory concentrations (MIC) for antibiotic classes in the published literature between January 1970 and June 2014. METHODS: We queried PUBMED and EMBASE for studies reporting antibiotic C. difficile MIC in English or French. We used mixed-effects models to obtain pooled estimates of antibiotic class median MIC (MIC50), 90th percentile of MIC (MIC90), and MIC90:MIC50 ratio. RESULTS: Our search identified 182 articles that met our inclusion criteria, of which 27 were retained for meta-analysis. Aminoglycosides (MIC50 120 mg/L, 95% CI 62-250), 3rd (MIC50 75 mg/L, 95% CI 39-130) and 2nd generation cephalosporins (MIC50 64 mg/L, 95% CI 27-140) had the least C. difficile activity. Rifamycins (MIC50 0.034 mg/L, 95% CI 0.012-0.099) and tetracyclines (MIC50 0.29 mg/L, 95% CI 0.054-1.7) had the highest level of activity. The activity of 3rd generation cephalosporins was more than three times lower than that of 1st generation agents (MIC50 19 mg/L, 95% CI 7.0-54). Time-trends in MIC50 were increasing for carbapenems (70% increase per 10 years) while decreasing for tetracyclines (51% decrease per 10 years). CONCLUSIONS: We found a 3500-fold variation in antibiotic C. difficile MIC50, with aminoglycosides as the least active agents and rifamycins as the most active. Further research is needed to determine how in vitro measures can help assess patient C. difficile risk and guide antimicrobial stewardship.

Impact of infection with extended-spectrum ß-lactamase-producing Escherichia coli or Klebsiella species on outcome and hospitalization costs.

BACKGROUND: Extended-spectrum ß-lactamase (ESBL)-producing bacteria are important sources of infection; however, Canadian data evaluating the impact of ESBL-associated infection are lacking. AIM: To determine whether patients infected with ESBL-producing Escherichia coli or Klebsiella species (ESBL-EcKs) exhibit differences in clinical outcome, microbiological outcome, mortality, and/or hospital resource use compared to patients infected with non-ESBL-producing strains. METHODS: A retrospective case-control study of 75 case patients with ESBL-EcKs matched to controls infected with non-ESBL-EcKs who were hospitalized from June 2010 to April 2013 was conducted. Patient-level cost data were provided by the institution's business office. Clinical data were collected using the electronic databases and paper charts. FINDINGS: Median infection-related hospitalization costs per patient were greater for cases than controls (C$10,507 vs C$7,882; median difference: C$3,416; P = 0.04). The primary driver of increased costs was prolonged infection-related hospital length of stay (8 vs 6 days; P = 0.02) with patient location (ward, ICU) and indirect care costs (including costs associated with infection prevention and control) as the leading cost categories. Cases were more likely to experience clinical failure (25% vs 11%; P = 0.03), with a higher all-cause mortality (17% vs 5%; P = 0.04). Less than half of case patients were prescribed appropriate empiric antimicrobial therapy, whereas controls received adequate initial treatment in nearly all circumstances (48% vs 96%; P < 0.01). CONCLUSION: Patients with infection caused by ESBL-EcKs are at increased risk for clinical failure and mortality, with additional cost to the Canadian healthcare system of C$3,416 per patient.

Is the prevalence of antibiotic-resistant organisms changing in Canadian hospitals? Comparison of point-prevalence survey results in 2010 and 2012.

A national point-prevalence survey for infection or colonization with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE), and for Clostridium difficile infection (CDI) was done in Canadian hospitals in 2010. A follow-up survey was done in November 2012 to determine whether there were any changes in the prevalence of these organisms; we also determined the prevalence of extended-spectrum ß-lactamase (ESBL)-producing Enterobacteriaceae, and carbapenem-resistant Enterobacteriaceae (CREs). Associations between prevalence and infection prevention and control policies were evaluated in logistic regression models. A total of 143 (67% of eligible facilities) hospitals with 29 042 adult inpatients participated in the survey, with representation from all 10 provinces; 132 hospitals participated in 2010 and 2012. There were no significant changes in the median prevalence of MRSA in 2010 (4.3%) compared to 2012 (3.9%), or of CDI in 2010 (0.8%) compared to 2012 (0.9%). A higher median prevalence of VRE was identified in 2012 (1.3%) compared to 2010 (0.5%) (p 0.04), despite decreased VRE screening in 2012. The median prevalence of ESBLs was 0.7% and was 0 for CREs; CREs were reported from only 10 hospitals (7.0%). A policy of routinely caring for patients with MRSA or VRE in a private isolation room was associated with lower prevalence of these organisms. Targeted screening of high-risk patients at admission was associated with lower MRSA prevalence; better hand hygiene compliance was associated with lower VRE prevalence. These data provide national prevalence rates for antibiotic-resistant organisms among adults hospitalized in Canadian hospitals. Certain infection prevention and control policies were associated with prevalence.

Complete sequences of a novel blaNDM-1-harbouring plasmid from Providencia rettgeri and an FII-type plasmid from Klebsiella pneumoniae identified in Canada.

OBJECTIVES: Emergence of plasmids harbouring bla(NDM-1) is a major public health concern due to their association with multidrug resistance and their potential mobility. METHODS: PCR was used to detect bla(NDM-1) from clinical isolates of Providencia rettgeri (PR) and Klebsiella pneumoniae (KP). Antimicrobial susceptibilities were determined using Vitek 2. The complete DNA sequence of two bla(NDM-1) plasmids (pPrY2001 and pKp11-42) was obtained using a 454-Genome Sequencer FLX. Contig assembly and gap closures were confirmed by PCR-based sequencing. Comparative analysis was done using BLASTn and BLASTp algorithms. RESULTS: Both clinical isolates were resistant to all ß-lactams, carbapenems, aminoglycosides, ciprofloxacin and trimethoprim/sulfamethoxazole, and susceptible to tigecycline. Plasmid pPrY2001 (113 295 bp) was isolated from PR. It did not show significant homology to any known plasmid backbone and contained a truncated repA and novel repB. Two bla(NDM-1)-harbouring plasmids from Acinetobacter lwoffii (JQ001791 and JQ060896) shared 100% similarity to a 15 kb region that contained bla(NDM-1). pPrY2001 also contained a type II toxin/antitoxin system. pKp11-42 (146 695 bp) was isolated from KP. It contained multiple repA genes. The plasmid backbone had the highest homology to the IncFIIk plasmid type (51% coverage, 100% nucleotide identity). The bla(NDM-1) region was unique in that it was flanked upstream by IS3000 and downstream by a novel transposon designated Tn6229. pKp11-42 also contained a number of mutagenesis and plasmid stability proteins. CONCLUSIONS: pPrY2001 differed from all known plasmids due to its novel backbone and repB. pKp11-42 was similar to IncFIIk plasmids and contained a number of genes that aid in plasmid persistence.

Molecular epidemiology of vancomycin-resistant enterococcal bacteraemia: results from the Canadian Nosocomial Infection Surveillance Program, 1999-2009.

OBJECTIVES: Vancomycin-resistant enterococci (VRE) can be associated with serious bacteraemia. The focus of this study was to characterize the molecular epidemiology of VRE from bacteraemia cases that were isolated from 1999 to 2009 as part of Canadian Nosocomial Infection Surveillance Program (CNISP) surveillance activities. METHODS: From 1999 to 2009, enterococci were collected from across Canada in accordance with the CNISP VRE surveillance protocol. MICs were determined using broth microdilution. PCR was used to identify vanA, B, C, D, E, G and L genes. Genetic relatedness was examined using multilocus sequence typing (MLST). RESULTS: A total of 128 cases of bacteraemia were reported to CNISP from 1999 to 2009. In 2007, a significant increase in bacteraemia rates was observed in western and central Canada. Eighty-one of the 128 bacteraemia isolates were received for further characterization and were identified as Enterococcus faecium. The majority of isolates were from western Canada (60.5%), followed by central (37.0%) and eastern (2.5%) Canada. Susceptibilities were as follows: daptomycin, linezolid, tigecycline and chloramphenicol, 100%; quinupristin/dalfopristin, 96.3%; high-level gentamicin, 71.6%; tetracycline, 50.6%; high-level streptomycin, 44.4%; rifampicin, 21.0%; nitrofurantoin, 11.1%; clindamycin, 8.6%; ciprofloxacin, levofloxacin and moxifloxacin, 1.2%; and ampicillin, 0.0%. vanA contributed to vancomycin resistance in 90.1% of isolates and vanB in 9.9%. A total of 17 sequence types (STs) were observed. Beginning in 2006 there was a shift in ST from ST16, ST17, ST154 and ST80 to ST18, ST412, ST203 and ST584. CONCLUSIONS: The increase in bacteraemia observed since 2007 in western and central Canada appears to coincide with the shift of MLST STs. All VRE isolates remained susceptible to daptomycin, linezolid, chloramphenicol and tigecycline.

Duration of hospital admission and the need for empirical antipseudomonal therapy.

To reduce selective pressure for antimicrobial resistance, empirical use of antipseudomonal antibiotics is often reserved for patients with late-onset hospital-acquired infections. We examined the likelihood of isolating Pseudomonas aeruginosa as a function of time from hospital admission. We conducted a retrospective cohort study of all positive bacterial cultures in a tertiary-care hospital between March 2010 and November 2011. The primary outcome was the proportion of positive cultures yielding P. aeruginosa. Multivariable logistic regression was employed to assess the impact of time from admission on the likelihood of isolating P. aeruginosa, after adjusting for other important risk factors. A total of 7,668 positive cultures were obtained from 4,108 unique patients during the study interval, including 633 (8.3%) yielding P. aeruginosa. The probability of isolating P. aeruginosa increased linearly from 79/2,044 (3.9%) positive cultures obtained on admission to 153/664 (23%) in the 10th week of admission or beyond. The unadjusted odds ratio was 1.002/day (95% confidence interval [CI], 1.0016 to 1.0028; P < 0.0001); the adjusted odds ratio (aOR) was 1.0007/day (95% CI, 1.0001 to 1.0013; P = 0.02). Other important predictors of P. aeruginosa isolation included respiratory specimen type (aOR, 13.8; 95% CI, 9.1 to 21.1), recent hospital admission (aOR,1.8; 95% CI, 1.4 to 2.3), prior P. aeruginosa isolation during current admission (aOR, 4.9; 95% CI, 3.7 to 6.4), and prior antipseudomonal (aOR, 1.9; 95% CI, 1.4 to 2.5) or nonantipseudomonal (aOR, 1.8; 95% CI, 1.4 to 2.4) antibiotic exposure. It was determined that as time from admission increases, there is a linear increase in the likelihood of P. aeruginosa isolation. Any guidelines which distinguish early from late hospital-acquired infection must consider the implications of time point selection on the likelihood of inadequate P. aeruginosa empirical coverage.

Carbapenem-resistant Gram-negative bacilli in Canada 2009-10: results from the Canadian Nosocomial Infection Surveillance Program (CNISP).

OBJECTIVES: To investigate the occurrence and molecular mechanisms associated with carbapenemases in carbapenem-resistant Gram-negative isolates from Canadian cases. METHODS: Twenty hospital sites across Canada submitted isolates for a 1 year period starting 1 September 2009. All Enterobacteriaceae with MICs ≥ 2 mg/L and Acinetobacter baumannii and Pseudomonas aeruginosa with MICs ≥ 16 mg/L of carbapenems were submitted to the National Microbiology Laboratory (NML) where carbapenem MICs were confirmed by Etest and isolates were characterized by PCR for carbapenemase genes, antimicrobial susceptibilities, PFGE and plasmid isolation. RESULTS: A total of 444 isolates (298 P. aeruginosa, 134 Enterobacteriaceae and 12 A. baumannii) were submitted to the NML of which 274 (61.7%; 206 P. aeruginosa, 59 Enterobacteriaceae and 9 A. baumannii) met the inclusion criteria as determined by Etest. Carbapenemase genes were identified in 30 isolates: bla(GES-5) (n = 3; P. aeruginosa), bla(KPC-3) (n = 7; Enterobacteriaceae), bla(NDM-1) (n = 2; Enterobacteriaceae), bla(VIM-2) and bla(VIM-4) (n = 8; P. aeruginosa) bla(SME-2) (n = 1; Enterobacteriaceae) and bla(OXA-23) (n = m9; A. baumannii). PFGE identified a cluster in each of Enterobacteriaceae, P. aeruginosa and A. baumannii corresponding to isolates harbouring carbapenemase genes. Three KPC plasmid patterns (IncN and FllA) were identified where indistinguishable plasmid patterns were identified in unrelated clinical isolates. CONCLUSIONS: Carbapenemases were rare at the time of this study. Dissemination of carbapenemases was due to both dominant clones and common plasmid backbones.

Audit of antibiotic duration of therapy, appropriateness and outcome in patients with nosocomial pneumonia following the removal of an automatic stop-date policy.

Automatic stop-orders (ASOs) have been utilized to discourage inappropriately prolonged antibiotic therapy. An ASO policy, which required reordering of antibiotics after 7 days of therapy, had been in place at our institution prior to 2002, but was revoked after instances of compromised patient care due to inadvertent and inappropriate interruption of antimicrobial treatment. The objective of this study was to evaluate the impact of revoking the ASO policy on the duration of antibiotic therapy, infection-related outcome (cure vs failure), relapsing infection, occurrence of resistant bacteria and superinfection in patients with nosocomial pneumonia. A retrospective chart review of adult patients (≥ 18 years old) admitted to Sunnybrook Health Sciences Centre with nosocomial pneumonia requiring antibiotic therapy was conducted. Duration of antibiotic therapy, infection-related outcome (cure vs failure), rate of relapsing infection, resistant organisms and superinfection were determined for each cohort. Forty-six eligible adults with nosocomial pneumonia per cohort were included [corrected]. Duration of antibiotic therapy was not significantly different in the pre- (11.4 ± 3.8 days) compared with the post-ASO revocation cohort (10.8 ± 4.1 days; p=0.43). There were also no significant differences between the cohorts with regard to infection-related outcome (cure vs failure), relapsing infection, or the occurrence of resistant bacteria or superinfection (p>0.5). Revocation of the ASO policy for antibiotics at our institution was not associated with a longer duration of antibiotic therapy, or increased incidence of infection-related mortality, relapsing infection, resistant bacteria or superinfection for patients with nosocomial pneumonia.

Comparison of mortality between nosocomial and community-acquired febrile neutropenia patients treated initially with cefazolin plus tobramycin: retrospective chart review.

Cefazolin plus tobramycin have been determined to be effective for community-acquired FN, but have not been evaluated in the treatment of nosocomial FN. This study compared the incidence of mortality from 2002 to 2004 with 2008 to 2009 in patients with nosocomial FN treated with cefazolin plus tobramycin and compared characteristics of patients with nosocomially acquired FN to community acquired FN. A retrospective chart review of 45 nosocomial FN episodes from 2008 to 2009, and 54 episodes from 2002 to 2004 treated with cefazolin plus tobramycin was conducted. Data on the community acquired FN episodes was obtained from our previous research. Nosocomial FN mortality increased from 4% in 2002-2004 to 13% in 2008-2009 (p = 0.08). The nosocomial cohort was at higher risk of medical complications and mortality than the community-acquired cohort based on several variables (neutrophil nadir, duration of neutropenia and fever, hematological malignancy, MASCC and Talcott score; p < 0.05). As a result, the nosocomial cohort was treated with longer courses of antibiotic therapy (14 days vs 7 days; p < 0.0001) and were more likely to require broader spectrum antibiotics (64 out of 99 vs 34 out of 96; p < 0.0001). There was an observed increased risk of mortality from 2002 to 2004 compared with 2008 to 2009 in patients treated with cefazolin plus tobramycin for nosocomial FN, this was notable despite not attaining statistical significance. Therefore, this regimen is not appropriate for nosocomial FN.

Evaluation of a new chromogenic medium (StrepB select) for detection of group B Streptococcus from vaginal-rectal specimens.

We compared StrepB Select medium (Select) after enrichment with conventional culture for the detection of Group B Streptococcus (GBS). Postenrichment sensitivities of Select and conventional culture were 98.8% and 92.2%, respectively (P<0.05). Select was superior for detection of GBS from vaginal-rectal specimens. Growth of non-GBS colonies required additional work to exclude the presence of GBS, especially after 48 h of incubation. Incubation of Select beyond 24 h did not significantly increase the yield of GBS.

Epidemiology of influenza-associated hospitalization in adults, Toronto, 2007/8.

The purpose of this investigation was to identify when diagnostic testing and empirical antiviral therapy should be considered for adult patients requiring hospitalization during influenza seasons. During the 2007/8 influenza season, six acute care hospitals in the Greater Toronto Area participated in active surveillance for laboratory-confirmed influenza requiring hospitalization. Nasopharyngeal (NP) swabs were obtained from patients presenting with acute respiratory or cardiac illness, or with febrile illness without clear non-respiratory etiology. Predictors of influenza were analyzed by multivariable logistic regression analysis and likelihoods of influenza infection in various patient groups were calculated. Two hundred and eighty of 3,917 patients were found to have influenza. Thirty-five percent of patients with influenza presented with a triage temperature >or=38.0 degrees C, 80% had respiratory symptoms in the emergency department, and 76% were >or=65 years old. Multivariable analysis revealed a triage temperature >or=38.0 degrees C (odds ratio [OR] 3.1; 95% confidence interval [CI] 2.3-4.1), the presence of respiratory symptoms (OR 1.7; 95% CI 1.2-2.4), admission diagnosis of respiratory infection (OR 1.8; 95% CI 1.3-2.4), admission diagnosis of exacerbation of chronic obstructive pulmonary disease (COPD)/asthma or respiratory failure (OR 2.3; 95% CI 1.6-3.4), and admission in peak influenza weeks (OR 4.2; 95% CI 3.1-5.7) as independent predictors of influenza. The likelihood of influenza exceeded 15% in patients with respiratory infection or exacerbation of COPD/asthma if the triage temperature was >or=38.0 degrees C or if they were admitted in the peak weeks during the influenza season. During influenza season, diagnostic testing and empiric antiviral therapy should be considered in patients requiring hospitalization if respiratory infection or exacerbation of COPD/asthma are suspected and if either the triage temperature is >or=38.0 degrees C or admission is during the weeks of peak influenza activity.

Variation in mortality rates among long-term care facilities for residents with lower respiratory tract infection.

OBJECTIVE: To identify variables contributing to interfacility differences in mortality among residents of long-term care facilities who have lower respiratory tract infection. DESIGN: Multicenter, prospective, 1-year observational study. SETTING: Twenty-one long-term care facilities in 4 geographic areas of Canada. PARTICIPANTS: Residents of long-term care facilities prescribed antimicrobials for treatment of lower respiratory tract infection. METHODS: Mortality rates were calculated for 3 definitions of lower respiratory tract infection: episodes with a clinical or radiographic diagnosis and treated with antimicrobials (definition 1); episodes with a physician diagnosis of pneumonia (definition 2); and episodes with chest radiography findings consistent with pneumonia (definition 3). Multilevel modeling was used to evaluate variables describing premorbid resident status, clinical presentation, management, and facility characteristics. Multivariable models were developed to identify independent predictors of mortality and determine whether facility-level variables remained independently associated with mortality rate after incorporation of individual-level variables. RESULTS: Facility mortality rates varied from 0% to 17.8% for definition 1, from 0% to 47.1% for definition 2, and from 0% to 37.5% for definition 3. There were significant differences in mortality rate depending on which definition was used; for definitions 1 and 2, there were significant differences in mortality rate across facilities. Poorer premorbid resident status and a more severe presentation remained independent predictors of mortality in the multivariable analysis. There were also significantly increased mortality rates for episodes in which a fluoroquinolone was prescribed for initial treatment. For definitions 1 and 3, facility-level variables remained independently associated with mortality rate in the final multivariable model. CONCLUSIONS: Rates of mortality due to lower respiratory tract infection varied among long-term care facilities and differed within a facility, depending on the definition applied. Variables describing premorbid resident status, severity of presentation, and management did not fully explain the variation in mortality rate. Some facility-level variables remained independent predictors of mortality.

Factors associated with critical-care healthcare workers' adherence to recommended barrier precautions during the Toronto severe acute respiratory syndrome outbreak.

OBJECTIVE: To assess factors associated with adherence to recommended barrier precautions among healthcare workers (HCWs) providing care to critically ill patients with severe acute respiratory syndrome (SARS). SETTING: Fifteen acute care hospitals in Ontario, Canada. DESIGN: Retrospective cohort study. PATIENTS: All patients with SARS who required intubation during the Toronto SARS outbreak in 2003. PARTICIPANTS: HCWs who provided care to or entered the room of a SARS patient during the period from 24 hours before intubation until 4 hours after intubation. METHODS: Standardized interviews were conducted with eligible HCWs to assess their interactions with the SARS patient, their use of barrier precautions, their practices for removing personal protective equipment, and the infection control training they received. RESULTS: Of 879 eligible HCWs, 795 (90%) participated. In multivariate analysis, the following predictors of consistent adherence to recommended barrier precautions were identified: recognition of the patient as a SARS case (odds ratio [OR], 2.5 [95% confidence interval {CI}, 1.5-4.5); recent infection control training (OR for interactive training, 2.7 [95% CI, 1.7-4.4]; OR for passive training, 1.7 [95% CI, 1.0-3.0]), and working in a SARS unit (OR, 4.0 [95% CI, 1.8-8.9]) or intensive care unit (OR, 4.3 [95% CI, 2.0-9.0]). Two factors were associated with significantly lower rates of consistent adherence: the provision of care for patients with higher Acute Physiology and Chronic Health Evaluation (APACHE) II scores (OR for score APACHE II of 20 or greater, 0.4 [95% CI, 0.28-0.68]) and work on shifts that required more frequent room entry (OR for 6 or more entries per shift, 0.5 [95% CI, 0.32-0.86]). CONCLUSIONS: There were significant deficits in knowledge about self-protection that were partially corrected by education programs during the SARS outbreak. HCWs' adherence to self-protection guidelines was most closely associated with whether they provided care to patients who had received a definite diagnosis of SARS.

Detection of severe acute respiratory syndrome coronavirus in stool specimens by commercially available real-time reverse transcriptase PCR assays.

Three commercially available real-time reverse transcriptase PCR assays (the Artus RealArt HPA coronavirus LightCycler, the Artus RealArt HPA coronavirus Rotor-Gene, and the EraGen severe acute respiratory syndrome coronavirus POL assay) and three RNA extraction methodologies were evaluated for the detection of severe acute respiratory syndrome coronavirus RNA from 91 stool specimens. The assays' sensitivities were highest (58% to 75%) for specimens obtained 8 to 21 days after symptom onset. The assays were less sensitive when specimens were obtained less than 8 days or more than 21 days after the onset of symptoms. All assays were 100% specific.

Hospital-acquired invasive group a streptococcal infections in Ontario, Canada, 1992-2000.

BACKGROUND: A significant proportion of invasive group A streptococcal infections are hospital acquired. No large, prospective studies have characterized this subgroup of cases and evaluated the risk of transmission in hospitals. METHODS: We conducted prospective, population-based surveillance of invasive group A streptococcal infections in Ontario, Canada, from 1992 to 2000. Epidemiologic and microbiologic investigations were conducted to identify cross-transmission. RESULTS: We identified 291 hospital-acquired cases (12.4%) among 2351 cases of invasive group A streptococcal disease. Hospital-acquired invasive group A streptococcal infections are heterogeneous, including surgical site (96 cases), postpartum (86 cases), and nonsurgical, nonobstetrical infections (109 cases). Surgical site infections affected 1 of 100,000 surgical procedures and involved all organ systems. Postpartum infections occurred at a rate of 0.7 cases per 10,000 live births and exhibited an excellent prognosis. Nonsurgical, nonobstetrical infections encompassed a broad range of infectious syndromes (case-fatality rate, 37%). Nine percent of cases were associated with in-hospital transmission. Transmission occurred from 3 of 142 patients with community-acquired cases of necrotizing fasciitis requiring intensive care unit (ICU) admission, compared with 1 of 367 patients with community-acquired cases without necrotizing fasciitis admitted to the ICU and 1 of 1551 patients with other cases (P<.001). Fifteen outbreaks were identified; 9 (60%) involved only 2 cases. Hospital staff were infected in 1 of 15 outbreaks, but colonized staff were identified in 6 (60%) of 10 investigations in which staff were screened. CONCLUSIONS: Presentation of hospital-associated invasive group A streptococcal infections is diverse. Cross-transmission is common; illness occurs in patients but rarely in staff. Isolation of new cases of necrotizing fasciitis and intervention after a single nosocomial case may also prevent transmission.