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The annual incidence rate of community-associated Clostridioides difficile infections in Quebec, Canada, has increased by 33.3%, from 0.51 (2008) to 0.68 (2015) cases/100,000 population, while incidence of healthcare-associated cases remained relatively stable. Possible causes include increased disease severity, increased antimicrobial drug use, emergence of virulent strains, and heightened physician awareness.

Background Asymptomatic patients colonized with Clostridioides difficile are at risk of developing C. difficile infection (CDI), but the factors associated with disease onset are poorly understood. Our aims were to identify predictors of hospital-onset CDI (HO-CDI) among colonized patients and to explore the potential benefits of primary prophylaxis to prevent CDI. Methods We conducted a retrospective cohort study in a tertiary academic institution. Colonized patients were identified by detecting the tcdB gene by polymerase chain reaction on a rectal swab. Univariate and multivariate logistic regression analyses were used to identify predictors of HO-CDI. Results There were 19 112 patients screened, from which 960 (5%) colonized patients were identified: 513 met the inclusion criteria. Overall, 39 (7.6%) developed a HO-CDI, with a 30-day attributable mortality of 15%. An increasing length of stay (adjusted odds ratio [aOR] per day, 1.03; P = .006), exposure to multiple classes of antibiotics (aOR per class, 1.45; P = .02), use of opioids (aOR, 2.78; P = .007), and cirrhosis (aOR 5.49; P = .008) were independently associated with increased risks of HO-CDI, whereas the use of laxatives was associated with a lower risk of CDI (aOR 0.36; P = .01). Among the antimicrobials, B-lactam with B-lactamase inhibitors (OR 3.65; P < .001), first-generation cephalosporins (OR 2.38; P = .03), and carbapenems (OR 2.44; P = .03) correlated with the greatest risk of HO-CDI. By contrast, patient age, the use of proton pump inhibitors, and the use of primary prophylaxis were not significant predictors of HO-CDI. Conclusions This study identifies several factors that are associated with CDI among colonized patients. Whether modifying these variables could decrease the risk of CDI should be investigated.

To study the microvascular density of the macular and optic nerve head in healthy and glaucoma subjects using optical coherence tomography angiography.We performed a cross-sectional cohort study on healthy subjects and patients with glaucoma. The AngioVue Enhanced Microvascular Imaging System was used to capture the optic nerve head and macula images during one visit. En face segment images of the macular and optic disc were studied in layers. Microvascular density of the optic nerve head and macula were quantified by the number of pixels measured by a novel in-house developed software. Areas under the receiver operating characteristic curves (AUROC) were used to determine the accuracy of differentiating between glaucoma and healthy subjects.A total of 24 (32 eyes) glaucoma subjects (57.5±9.5-y old) and 29 (58 eyes) age-matched controls (51.17±13.5-y old) were recruited. Optic disc and macula scans were performed showing a greater mean vessel density (VD) in healthy compared with glaucoma subjects. The control group had higher VD than the glaucoma group at the en face segmented layers of the optic disc (optic nerve head: 0.209±0.05 vs. 0.110±0.048, P0.001; vitreoretinal interface: 0.086±0.045 vs. 0.052±0.034, P=0.001; radial peripapillary capillary: 0.146±0.040 vs. 0.053±0.036, P0.001; and choroid: 0.228±0.074 vs. 0.165±0.062, P0.001). Similarly, the VD at the macula was also greater in controls than glaucoma patients (superficial retina capillary plexus: 0.115±0.016 vs. 0.088±0.027, P0.001; deep retina capillary plexus: 0.233±0.027 vs. 0.136±0.073, P0.001; outer retinal capillary plexus: 0.190±0.057 vs. 0.136±0.105, P=0.036; and choriocapillaris: 0.225±0.053 vs. 0.153±0.068, P0.001. The AUROC was highest for optic disc radial peripapillary capillary (0.96), followed by nerve head (0.92) and optic disc choroid (0.76). At the macula, the AUROC was highest for deep retina (0.86), followed by choroid (0.84), superficial retina (0.81), and outer retina (0.72).Microvascular density of the optic disc and macula in glaucoma patients was reduced compared with healthy controls. VD of both optic disc and macula had a high diagnostic ability in differentiating healthy and glaucoma eyes.

Cell cytotoxicity neutralization assay (CCNA) is considered to be a gold standard to diagnose Clostridioides difficile infections. We performed CCNA on 77 consecutive admission screening rectal swabs from asymptomatic toxigenic C. difficile carriers. Thirty-nine percent of specimens from asymptomatic carriers were positive. Thus, CCNA specificity may be lower than previously thought.

Study Objective: To externally validate a risk-stratification tool—the Quick COVID-19 Severity Index (qCSI)—developed by Haimovich et al. to predict 24-hour respiratory decompensation in admitted patients with COVID-19. Methods: This was a retrospective observational cohort study of COVID-19 patients admitted from the emergency department between Feb 29, 2020 to Feb 1, 2021. The health care system is composed of a mix of 2 community and 4 academics EDs in a major metropolitan area. Patient demographics, vital signs, laboratory results were extracted from our institutional COVID-19 Data Warehouse. Following the convention of qCSI variables, respiratory rate (breaths/min), pulse oximetry (%), and oxygen flow rate (L/min) were used to calculate points between 0 to 12, with higher points associated with highly likelihood of respiratory decompensation within 24 hours. Results: 35,696 COVID-19 patients were admitted via the emergency department during the study period. The mean qCSI was 1.73 (SD 1.82) for non-ICU admissions (n=34,647). The mean qCSI was 2.83 (SD 2.53) for ICU admission (n=1,049). As of the time of submission, ED treat and release patients, as well as decompensation results are pending. Conclusions: In this validation study of qCSI using a large system cohort of COVID-19 patients, qCSI appears to correlate strongly with clinical triage for admission decision to regular floor vs. ICU level care. Further analysis is needed to identify 24-hour respiratory decompensation after regular floor admission.

Study Objectives: Among patients admitted with coronavirus, vital signs recorded at initial emergency department (ED) presentation may inform outcomes Our objective was to assess the impact of presenting vital signs on discharge after hospitalization, neurological sequelae, and hospital length of stay Methods: We conducted a retrospective investigation at Elmhurst Hospital (Queens, New York) recognized as “the epicenter of the epicenter” of the 2020 coronavirus pandemic Included were 2216 adult patients who tested positive for coronavirus We studied vital signs recorded upon initial ED presentation including oxygen saturation, respiratory rate, temperature, heart rate, and blood pressure We used multivariable logistic regression models to test for associations between presenting vital signs and discharge after hospitalization, neurological sequelae (cognitive/sensory/motor changes, new emotional instability, new onset seizures), and hospital length of stay Results: Upon abstract submission, data abstraction was still ongoing Preliminary analysis suggested an association between higher initial oxygen saturation and increased odds of discharge after hospitalization (OR 1 108, 95% CI 1 004-1 223) It also suggested an association between higher initial respiratory rate and increased odds of neurological sequelae (OR 1 156, 95% CI 1 008-1 327) No association was observed between presenting temperature, heart rate, blood pressure, and outcomes Conclusion: Among patients hospitalized with coronavirus, initial vital signs obtained at ED presentation provide useful prognostic information on short term outcomes

Clostridioides difficile is the leading cause of diarrhea in hospitalized U.S. patients and results in over 400,000 cases of C. difficile infection per year. C. difficile infections have mortality rates of 6 to 30% and significantly increase health care costs, because of increased length of stay and increased frequency of readmissions due to recurrences. Efforts to reduce the spread of C. difficile in hospitals have led to the development of rapid sensitive diagnostic methods., Clostridioides difficile is the leading cause of diarrhea in hospitalized U.S. patients and results in over 400,000 cases of C. difficile infection per year. C. difficile infections have mortality rates of 6 to 30% and significantly increase health care costs, because of increased length of stay and increased frequency of readmissions due to recurrences. Efforts to reduce the spread of C. difficile in hospitals have led to the development of rapid sensitive diagnostic methods. A multicenter study was performed to establish the performance characteristics of the Revogene C. difficile test (Meridian Bioscience, Cincinnati, OH, USA) for use in detection of the toxin B (tcdB) gene from toxigenic C. difficile. The Revogene instrument is a new molecular platform that uses real-time PCR to detect nucleic acids in up to 8 specimens at a time. A total of 2,461 specimens from symptomatic patients that had been submitted for C. difficile testing were enrolled at 7 sites throughout the United States and Canada for evaluation of the assay. Each stool specimen was tested for the presence of the tcdB gene using the Revogene C. difficile test, and results were compared with those of the reference method, a combination of direct and enriched culture methods. Overall, the Revogene C. difficile test demonstrated a sensitivity of 85.0% (95% confidence interval, 80% to 88%) and a specificity of 97.2% (95% confidence interval, 96% to 98%). The Revogene C. difficile test, using clinical stool specimens for detection of tcdB in C. difficile, demonstrated acceptable sensitivity and specificity, with a short turnaround time.

Background: Choosing Wisely Canada is a forum for health care professional societies to lead system change through identification and reduction of low-value practices. Microbiologic investigations are frequently overused and may contribute to unnecessary health care expenditures as well as patient harm. Methods: A Choosing Wisely Canada top five list in medical microbiology was developed by the Association of Medical Microbiology and Infectious Disease (AMMI) Canada through broad consultation of its members. Following an electronic survey of members, recommendations were developed and ranked by a working group, then further narrowed during a national open forum using the modified Delphi method. Feedback was solicited through an online forum prior to dissemination. Results: The top five declarative statements in medical microbiology are: ( 1 ) Don’t collect urine specimens for culture from adults who lack symptoms localizing to the urinary tract or fever, ( 2 ) Don’t routinely collect or process specimens for Clostridium difficile testing when stool is non-liquid or if the patient has had a prior nucleic acid amplification test result within the past 7 days, ( 3 ) Don’t obtain swabs from superficial ulcers for culture, ( 4 ) Don’t routinely order nucleic acid amplification testing on cerebrospinal fluid in patients without a compatible clinical syndrome, and ( 5 ) Don’t routinely obtain swabs during surgical procedures when fluid and/or tissue samples can be collected. Conclusions: This Choosing Wisely list represents a launching point to reduce low-value practices in microbiology. Strong implementation science around these statements will be needed to improve the value of microbiology testing in Canada.

A panel of experts was convened by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) to update the 2010 clinical practice guideline on Clostridium difficile infection (CDI) in adults. The update, which has incorporated recommendations for children (following the adult recommendations for epidemiology, diagnosis, and treatment), includes significant changes in the management of this infection and reflects the evolving controversy over best methods for diagnosis. Clostridium difficile remains the most important cause of healthcare-associated diarrhea and has become the most commonly identified cause of healthcare-associated infection in adults in the United States. Moreover, C. difficile has established itself as an important community pathogen. Although the prevalence of the epidemic and virulent ribotype 027 strain has declined markedly along with overall CDI rates in parts of Europe, it remains one of the most commonly identified strains in the United States where it causes a sizable minority of CDIs, especially healthcare-associated CDIs. This guideline updates recommendations regarding epidemiology, diagnosis, treatment, infection prevention, and environmental management.

Background: Emergency department clinicians often overlook asymptomatic hypertension (HTN). Clinical decision support can help improve adherence to the emergency nursing and emergency medicine clinical policy for asymptomatic HTN. While the policy indicates referral for all adults with two or more elevated blood pressures, less than 10% of patients are referred. We sought to determine the efficacy of an electronic health record clinical reminder on nursing (RN) reassessment of blood pressure (BP) for hypertensive patients. Methods: We conducted a 2-arm, pilot RCT, at an academic medical center in New York City. 107 RNs were randomized to the control group or to the intervention of a 'Best Practice Alert' (BPA) reminding him/her to recheck the BP in adult patients with an initial BP reading ≥140/90 mmHg. Descriptive statistics that included univariate and bivariate analyses were used to obtain adjusted measures of association between the intervention and control group. Results: RNs were more likely to repeat BP after receiving a BPA alert (56%) compared to RNs who did not receive an alert (44%) (OR=2.3, CI 2.1-2.5; p75 years (OR 1.47; CI 1.07-2.03; p=.02); had Stage II HTN (OR 3.48; CI 2.63-4.59, p=.0001) and an ED length of stay of 3-4 hours (OR 5.85; CI 4.43-7.73; p=.0001). Conclusion: The BPA alert was effective in increasing BP reassessment by ED nurses. The findings of this study will help us translate this evidence ED practices.

Background The isolation of asymptomatic Clostridium difficile (CD) carriers may decrease the incidence of hospital-associated C. difficile infections (CDI), but its impact on isolation precaution needs is unknown. Methods A time series analysis was conducted to investigate the impact of isolating CD carriers on the burden of isolation precautions from 2008 to 2016 in a Canadian hospital. To account for the changes in C. difficile infection control policies, the series was divided into 3 intervention periods: period 1 (2008-2011), isolation of patients with CDI until symptom resolution; period 2 (2011-2013), isolation of patients with CDI until discharge; and period 3 (2013-2016), isolation of patients with CDI and CD carriers until discharge. We compared the prevalence of isolation-days for C. difficile (ie, for either CDI or carriage) per 1000 patient-days between study periods. Changes in trend were analyzed by segmented regression analysis. Results A total of 806357 patient-days and 20455 isolation-days were included. Isolation-day prevalence during periods 1, 2, and 3 were 12.9, 26.2, and 37.8 isolation-days per 1000 patient-days, respectively (P < .001 between periods). Isolating CD carriers was associated with an increase in isolation-days' prevalence compared with period 2 (rate ratio [RR], 1.66; P < .001) followed by a significant decrease in trend (RR per 4-week period, 0.97; P < .001). The downward trend was mainly due to decreasing isolation needs for patients with CDI (RR per 4-week period, 0.94; P < .001) rather than for carriage (RR per 4-week period, 0.996; P = .21). Conclusions Isolating CD carriers led to an initial increase in isolation needs that was partially compensated by a decrease in isolation needs for CDI.

Background Several Clostridium difficile infection (CDI) surveillance programs do not specify laboratory strategies to use. We investigated the evolution in testing strategies used across Quebec, Canada, and its association with incidence rates. Methods Cross-sectional study of 95 hospitals by surveys conducted in 2010 and in 2013-2014. The association between testing strategies and institutional CDI incidence rates was analyzed via multivariate Poisson regressions. Results The most common assays in 2014 were toxin A/B enzyme immunoassays (EIAs) (61 institutions, 64%), glutamate dehydrogenase (GDH) EIAs (51 institutions, 53.7%), and nucleic acid amplification tests (NAATs) (34 institutions, 35.8%). The most frequent algorithm was a single-step NAAT (20 institutions, 21%). Between 2010 and 2014, 35 institutions (37%) modified their algorithm. Institutions detecting toxigenic C difficile instead of C difficile toxin increased from 14 to 37 ( P C difficile had higher CDI rates (7.9 vs 6.6 per 10,000 patient days; P = .01). Institutions using single-step NAATs, GDH plus toxigenic cultures, and GDH plus cytotoxicity assays had higher CDI rates than those using an EIA-based algorithm ( P Conclusions Laboratory detection of CDI has changed since 2010. There is an association between diagnostic algorithms and CDI incidence. Mitigation strategies are warranted.

Background Respiratory tract infections are frequent causes of hospitalization and initiation of empirical antimicrobial therapy. Testing for a broad panel of respiratory viruses has been advocated as a useful tool for antibiotic stewardship. We conducted a prospective observational study to assess the impact of rapid viral test results on antimicrobial prescriptions and clinical outcomes among hospitalized adults. Methods Eight hundred patients admitted with respiratory symptoms were tested by a 12-virus respiratory panel (RVP) during 3 consecutive winters in Montreal, Canada. The primary outcome measure was change in antimicrobial prescriptions (ie, de-escalation of empirical antimicrobial therapy or commencement of new antimicrobial therapy) after RVP results were available. Clinical outcomes were also assessed. Results Influenza virus was identified in 53% of individuals in the study population, and other viruses were identified in 10%. Influenza virus positivity was associated with shorter duration of hospitalization and appropriate antiviral management. Antibiotic management was most significantly correlated with radiographic suspicion of pneumonia and less so with results of the RVP. Positivity for viruses other than influenza virus was not correlated with significantly different outcomes. Conclusions Physicians respond to results of testing for influenza virus when managing hospitalized adult patients but respond less to test results for other viruses. These data can inform the design of stewardship interventions and the selection of viral testing panels for hospitalized patients.

Background Acute invasive fungal infections of the head and neck secondary to tyrosine kinase inhibitors are rare and potentially life-threatening events. Case presentation We report a case of mucormycosis of the thyroid gland in a patient known for chronic lymphocytic leukemia receiving ibrutinib who presented with a rapidly growing thyroid nodule and dysphonia. An acute invasive fungal infection was identified on a core needle biopsy; mucormycosis was confirmed on culture. The patient was successfully treated with surgical debridement and long-term antifungal therapy. Conclusion Patients on ibrutinib may be at risk of acute invasive fungal infections of the head and neck.

Background Numerous studies have identified comorbidities that are associated with Clostridioides difficile infection (CDI), but current CDC and CMS models for risk adjusting hospital CDI rates do not include patient comorbid conditions. Incorporating patient-level data could improve CDI risk adjustment, but comorbidities would need to be easily electronically available for widescale implementation. Ideally, they would also be causally related to CDI — i.e., true risk factors, not confounders — to facilitate more unbiased inter-hospital comparisons. The current study aimed to determine which comorbid conditions are causally related to CDI based upon expert consensus. Methods We used Delphi methodology to administer an iterative, two-round survey with an intervening teleconference, to eight infectious disease experts. Experts evaluated 40 comorbid conditions included in Charlson and Elixhauser comorbidity indices (and thus validated for electronic capture through administrative data), as well as other comorbidities commonly associated with CDI. Experts rated comorbid conditions from 1 (not at all related) to 5 (strongly related), based upon perceived relatedness with CDI. To assign causal relatedness, the following criteria had to be met at the end of round two: 1) majority (> 50%) of experts rating the condition at 3 (somewhat related) or higher; 2) inter-quartile range (IQR) < = 1; and 3) standard deviation (SD) < = 1. Results 8/40 (20%) comorbid conditions were ranked as causally related to CDI, including patient age, three malignancy comorbidities, two transplant-related comorbidities, HIV/AIDS, and inflammatory bowel disease. A further 18/40 (45%) qualified as indeterminately related, and 14/40 (35%) were ranked as not causally related to CDI (Table). Three of the eight causally related factors were not components of Elixhauser or Charlson indices. Table Conclusion We identified comorbid conditions that may be appropriate candidates to consider for inclusion in patient-level risk adjustment models. Some causal factors did not originate from established comorbidity indices. Thus, future work to validate electronic capture of these conditions could further reduce barriers to risk-adjustment implementation. Disclosures All Authors: No reported disclosures

Study Objective: New York City Health + Hospitals/Elmhurst located in Queens, New York, has one of the most diverse patient populations in the United States, and likely the world, and was deemed the “epicenter” of the Covid-19 pandemic in 2020 Given its unique population, high number of Covid-19 cases and growing concern that Covid-19 disproportionately affects minority patients, this study seeks to examine the correlation between ethnicity and time from symptoms onset to ED presentation to further understand this disparity Methods: This is a retrospective chart review of 2216 patients who tested positive for SARS-CoV-2 (COVID-19) with 2254 unique ED visits Preliminary analysis was conducted on 212 of these patients with data extracted from Epic through chart review for time from symptom onset to ED presentation and documented ethnicity, defined for this study as Hispanic or non-Hispanic Symptom onset to ED presentation was defined as one of seven categories: one through seven days or >1 week The data were analyzed using statistical analysis software to assess for correlation between ethnicity and time of symptom onset to ED presentation Results: Results demonstrated that 37 5% of Hispanics presented to the ED after one week of symptoms as compared to 34 9% of non-Hispanics (p>0 05) Of non-Hispanics, 22 2% presented after one day of symptoms While not, statistically significant, this demonstrates a trend toward Hispanics having a delay from symptom onset to ED presentation Further analysis of available data is pending Conclusion: Based on preliminary data, ethnicity does not seem to predict symptom onset to ED presentation This aids in determining causes of high mortality rates of COVID-19 minority populations Several media outlets have suggested that COVID-19 has disproportionately affected minorities and this paper sought to examine possible confounders to this statement Further research and analyses are underway and it is hypothesized that other social determinants of health care likely play a role in this disparity

Background Whole genome sequencing (WGS) studies can enhance our understanding of the role of patients with asymptomatic Clostridium difficile colonization in transmission. Methods Isolates obtained from patients with Clostridium difficile infection (CDI) and colonization identified in a study conducted during 2006 - 2007 at six Canadian hospitals underwent typing by pulsed-field gel electrophoresis, multilocus sequence typing, and WGS. Isolates from incident CDI cases not in the initial study were also sequenced where possible. Ward movement and typing data were combined to identify plausible donors for each CDI case, as defined by shared time and space within predefined limits. Proportions of plausible donors for CDI cases that were colonized, infected, or both were examined. Results Five hundred and fifty-four isolates were sequenced successfully, 353 from colonized and 201 from CDI cases. The NAP1/027/ST1 strain was the most common strain, found in 124 (62%) of infected and 92 (26%) of colonized patients. A donor with a plausible ward link was found for 81 CDI cases (40%) using WGS with a threshold of ≤2 single nucleotide variants to determine relatedness. Sixty-five (32%) CDI cases could be linked to both infected and colonized donors. Exclusive linkages to infected and colonized donors were found for 28 (14%) and 12 (6%) CDI cases, respectively. Conclusion Colonized patients contribute to transmission, but CDI cases are more likely linked to other infected patients than colonized patients in this cohort with high rates of NAP1/027/ST1 strain, highlighting the importance of local prevalence of virulent strains in determining transmission dynamics.

During 4 Clostridium difficile infection outbreaks, unit-wide screening of 114 patients led to detection and isolation of 15 (13%) C. difficile asymptomatic carriers. Carriage prevalence varied between outbreaks, from 0% to 29% (P = .004). Isolating carriers was not associated with significantly shorter outbreak durations, compared with historical controls.

SUMMARY Clostridium difficile is the main causative agent of antibiotic-associated and health care-associated infective diarrhea. Recently, there has been growing interest in alternative sources of C. difficile other than patients with Clostridium difficile infection (CDI) and the hospital environment. Notably, the role of C. difficile -colonized patients as a possible source of transmission has received attention. In this review, we present a comprehensive overview of the current understanding of C. difficile colonization. Findings from gut microbiota studies yield more insights into determinants that are important for acquiring or resisting colonization and progression to CDI. In discussions on the prevalence of C. difficile colonization among populations and its associated risk factors, colonized patients at hospital admission merit more attention, as findings from the literature have pointed to their role in both health care-associated transmission of C. difficile and a higher risk of progression to CDI once admitted. C. difficile colonization among patients at admission may have clinical implications, although further research is needed to identify if interventions are beneficial for preventing transmission or overcoming progression to CDI.

Background Clostridium difficile (CD) is the leading cause of health care–associated diarrhea and can result in asymptomatic carriage. Rates of asymptomatic CD colonization on hospital admission range from 1.4%-21%. The objective of this study was to evaluate host and bacterial factors associated with colonization on admission. Methods The Consortium de recherche quebecois sur le Clostridium difficile study provided data for analysis, including demographic information, known risk factors, and potential confounding factors, prospectively collected for 5,232 patients from 6 hospitals in Quebec and Ontario over 15 months from 2006-2007. Stool or rectal swabs were obtained for culture on admission. Pulsed-field gel electrophoresis was performed on the isolates. The presence of antibody against CD toxins A and B was measured. Results There were 212 (4.05%) patients colonized with CD on admission, and 5,020 patients were not colonized with CD. Multivariate logistic regression analysis showed that hospitalization within the last 12 months, use of corticosteroids, prior CD infection, and presence of antibody against toxin B were associated with colonization on admission. Of patients colonized on admission, 79.4% had non-NAP1, non-NAP2 strains. Conclusion There are identifiable risk factors among asymptomatic CD carriers that could serve in their detection and provide a basis for targeted screening.

The control of Clostridium difficile infection is paramount. C difficile spores are difficult to eradicate and can survive on surfaces for prolonged periods of time. Hand washing with either plain or antimicrobial soap is effective in removing C difficile spores from hands. Patients should be placed in private rooms and under contact precautions to prevent transmission to other patients. Regular hospital germicides are not sporicidal and hypochlorite solutions are required for surface disinfection. In outbreak situations, a multifaceted approach is required.

Hantaviruspulmonary syndrome (HPS) is a rare illness in eastern Canada. We present three cases of HPS among military personnel in Quebec. The three cases shared a common exposure to mouse excreta while engaged in military training in Alberta, a western province of Canada.

Clostridium difficile infection is the leading cause of health care-associated diarrhea, and the bacterium can also be carried asymptomatically. The objective of this study was to identify host and bacterial factors associated with health care-associated acquisition of C. difficile infection and colonization.We conducted a 15-month prospective study in six Canadian hospitals in Quebec and Ontario. Demographic information, known risk factors, potential confounding factors, and weekly stool samples or rectal swabs were collected. Pulsed-field gel electrophoresis (PFGE) was performed on C. difficile isolates to determine the genotype. Levels of serum antibodies against C. difficile toxins A and B were measured.A total of 4143 patients were included in the study; 117 (2.8%) and 123 (3.0%) had health care-associated C. difficile infection and colonization, respectively. Older age and use of antibiotics and proton-pump inhibitors were significantly associated with health care-associated C. difficile infection. Hospitalization in the previous 2 months; use of chemotherapy, proton-pump inhibitors, and H(2) blockers; and antibodies against toxin B were associated with health care-associated C. difficile colonization. Among patients with health care-associated C. difficile infection and those with colonization, 62.7% and 36.1%, respectively, had the North American PFGE type 1 (NAP1) strain.In this study, health care-associated C. difficile infection and colonization were differentially associated with defined host and pathogen variables. The NAP1 strain was predominant among patients with C. difficile infection, whereas asymptomatic patients were more likely to be colonized with other strains. (Funded by the Consortium de Recherche sur le Clostridium difficile.).

Background Patients who are colonized with C. difficile are at risk of developing C. difficile infections (CDI), but factors associated with disease onset are poorly understood. The objectives of this study were to identify predictors of hospital-onset CDI (HO-CDI) among asymptomatic C. difficile colonized patients and explore the potential benefit of primary prophylaxis to prevent CDI. Methods We performed a retrospective cross-sectional study of C. difficile colonized patients admitted to a tertiary academic institution in Quebec City between November 2013 and January 2017. Colonization status was determined upon hospital admission through a systematic screening program by detecting the TcdB gene by PCR on a rectal swab. Primary prophylaxis was defined as the preventive use of ≥1 dose of oral vancomycin or metronidazole in a patient without diarrhea. The choice and dosing of prophylaxis were left to the discretion of the treating physician. Univariate and multivariate logistic regression analyses were used to determine independent predictors of HO-CDI. Results Of 513 C. difficile colonized patients, 39 (7.6%) developed a HO-CDI, with a 30-day attributable mortality of 18%. We found that an increased length of hospital stay (adjusted odds ratio [aOR] per day, 1.03; P = 0.006), exposure to multiple classes of systemic antibiotics (aOR per class of antibiotic, 1.45; P = 0.03), the use of opioid analgesics (aOR, 2.70; P = 0.01) and cirrhosis (aOR, 5.57; P = 0.007), were independently associated with an increased risk of HO-CDI in multivariate analysis, whereas the use of laxatives was associated with a lower risk of CDI (aOR, 0.36; P = 0.01). Among the antimicrobials, B-lactam with B-lactamase inhibitors (OR, 3.65; P < 0.001), first-generation cephalosporins (OR, 2.38; P = 0.03), and carbapenems (OR, 2.44; P = 0.03) correlated with the greatest risk of HO-CDI. In contrast, patient age, exposure to proton pump inhibitors, and the use of prophylaxis were not significantly associated with occurrence of HO-CDI in this specific population. Conclusion This study identifies several variables that are specifically associated with the development of CDI among C. difficile colonized patients. Whether modifying these risk factors could help prevent CDI should be further investigated. Disclosures S. Trottier, CIHR: Grant Investigator, Research grant. V. Loo, Merck: Consultant and Scientific Advisor, Consulting fee. Y. Longtin, Merck: Grant Investigator, Research grant. Becton Dickinson: Grant Investigator, Grant recipient.

Since publication of the Society for Healthcare Epidemiology of America position paper onClostridium difficileinfection in 1995, significant changes have occurred in the epidemiology and treatment of this infection.C. difficileremains the most important cause of healthcare-associated diarrhea and is increasingly important as a community pathogen. A more virulent strain ofC. difficilehas been identified and has been responsible for more-severe cases of disease worldwide. Data reporting the decreased effectiveness of metronidazole in the treatment of severe disease have been published. Despite the increasing quantity of data available, areas of controversy still exist. This guideline updates recommendations regarding epidemiology, diagnosis, treatment, and infection control and environmental management.

Objective.To evaluate common hand hygiene methods for efficacy in removingClostridium difficik.Design.Randomized crossover comparison among 10 volunteers with hands experimentally contaminated by nontoxigenic C.difficile.Methods.Interventions included warm water with plain soap, cold water with plain soap, warm water with antibacterial soap, antiseptic hand wipes, alcohol-based handrub, and a control involving no Intervention. All interventions were evaluated for mean reduction in colony-forming units (CFUs) under 2 contamination protocols: “whole hand” and “palmar surface.” Results were analyzed according to a Bayesian approach, by using hierarchical models adjusted for multiple observations.Results.Under the whole-hand protocol, the greatest adjusted mean reductions were achieved by warm water with plain soap (2.14 log10CFU/mL [95% credible interval (Cri), 1.74-2.54 log10CFU/mL]), cold water with plain soap (1.88 log10CFU/mL [95% Cri, 1.48-2.28 log10CFU/mL), and warm water with antibacterial soap (1.51 log10CFU/mL [95% Cri, 1.12-1.91 logu, CFU/mL]), followed by antiseptic hand wipes (0.57 log10CFU/mL [95% Cri, 0.17-0.96 log10CFU/mL]). Alcohol-based handrub (0.06 log10CFU/mL [95% CrI, -0.34 to 0.45 log10CFU/mL]) was equivalent to no Intervention. Under the palmar surface protocol, warm water with plain soap, cold water with plain soap, and warm water with antibacterial soap again yielded the greatest mean reductions, followed by antiseptic hand wipes (26.6, 26.6, 26.6, and 21.9 CFUs per plate, respectively), when compared with alcohol-based handrub. Hypothenar (odds ratio, 10.98 [95% Cri, 1.96-37.65]) and thenar (odds ratio, 6.99 [95% Cri, 1.25-23.41]) surfaces were more likely than fingertips to remain heavily contaminated after handwashing.Conclusions.Handwashing with soap and water showed the greatest efficacy in removingC. difficileand should be performed preferentially over the use of alcohol-based handrubs when contact withC. difficileis suspected or likely.

Antimicrobial therapy plays a central role in the pathogenesis of Clostridium difficile infection (CDI), presumably through disruption of indigenous intestinal microflora, thereby allowing C. difficile to grow and produce toxin. Investigations involving animal models and studies performed in vitro suggest that inhibitory activity against C. difficile and differences in the propensity to stimulate toxin production may also influence the likelihood that particular drugs may cause CDI. Although nearly all antimicrobial classes have been associated with CDI, clindamycin, third-generation cephalosporins, and penicillins have traditionally been considered to harbor the greatest risk. Recent studies have also implicated fluoroquinolones as high-risk agents, a finding that is most likely to be related in part to increasing fluoroquinolone resistance among epidemic strains (i.e., restriction-endonuclease analysis group BI/North American PFGE type 1 strains) and some nonepidemic strains of C. difficile. Restrictions in the use of clindamycin and third-generation cephalosporins have been associated with reductions in CDI. Because use of any antimicrobial has the potential to induce the onset of CDI and disease caused by other health care-associated pathogens, antimicrobial stewardship programs that promote judicious use of antimicrobials are encouraged in concert with environmental and infection control-related efforts.

Objective:To evaluate the airborne viable bacterial concentrations generated during sputum induction and their reduction with exhaust ventilation, ultraviolet germicidal irradiation (UVGI), or both.Methods:Exhaust ventilation, upper air UVGI lights, and a portable UVGI unit were operated independently or in combination while and after sputum induction was performed for 58 patients suspected of having active tuberculosis. Viable airborne bacteria were sampled with volumetric air samplers, grown on blood agar, and identified with standard techniques.Results:During and immediately after sputum induction, concentrations of airborne bacteria, particularly respiratory tract or oropharyngeal organisms, increased rapidly, regardless of environmental conditions. The subsequent rate of reduction of airborne bacteria was most rapid with the portable UVGI unit, followed by upper air UVGI with air mixing. Exhaust ventilation achieved high air changes per hour, but efficacy in reducing airborne bacterial concentrations was low. However, the continuous entrainment of bacteria-laden air from the hallway outside may have resulted in underestimation. The efficacy of a wall-mounted upper air UVGI fixture was significantly less if there was no air mixing. The irradiation from this fixture was of adequate germicidal intensity only in a narrow horizontal plane 2.5 m above the floor.Conclusion:Sputum induction was associated with a rapid and substantial increase in airborne bacteria despite the use of exhaust ventilation providing more than 30 air changes per hour, and the adjunct use of UVGI. This emphasizes that health-care workers involved in similar cough-inducing procedures performed for patients with suspected tuberculosis must wear appropriate personal respirators (Infect Control Hosp Epidemiol2003;24:483-489)

Background: Nosocomial transmission of methicillin-resistant Staphylococcus aureus (MRSA) occurs primarily through the contaminated hands of health care workers who do not follow appropriate precautionary measures. This study investigates various factors associated with compliance with MRSA precautions during routine patient care. Methods: This observational study took place at a teaching hospital in Montreal, Canada. Nurses (184), physicians (41), occupational therapists and physical therapists (19), orderlies (102), housekeeping personnel (28), other health care workers (65), and visitors (49) were anonymously observed. Compliance with MRSA precautions was measured according to appropriate use of gowns and gloves as well as hand hygiene. Results: In 488 observations, the average compliance was 28%. In multivariate analysis, in comparison with nurses, compliance was lower among physicians (odds ratio [OR], 0.35; 95% confidence interval [CI], 0.14 to 0.86), orderlies (OR, 0.37; CI, 0.2-0.69), visitors (OR, 0.2; CI, 0.08-0.49), housekeeping personnel (OR, 0.06; CI, 0.01-0.47), and other types of health care workers (OR, 0.39; CI, 0.18-0.85), but was higher among occupational and physical therapists (OR, 11.7; CI, 2.55-53.8). Conclusions: Compliance with MRSA precautions is low. The only significant predictor of MRSA compliance was the professional category of the health care worker. (Am J Infect Control 2002;30:430-3.)

Background Patients with symptomatic Clostridium difficile infection (CDI) are thought to be responsible for most transmission events, but whole genome sequencing (WGS) studies have raised interest in asymptomatic carriers’ role in transmission. Methods Patients with CDI and colonization were identified using weekly screening in a study conducted during 2006–2007 at six Canadian hospitals. Isolates were typed using pulsed-field gel electrophoresis (PFGE), multi-locus sequence typing (MLST), and WGS. Toxigenic status was determined using cytotoxin testing and tcdB PCR. Incident CDI cases, not included in the initial study, were also sequenced where possible. Ward movement and typing data were combined to identify plausible donors for each CDI case, as defined by shared time and space on the same ward within predefined limits (infectious period Results A total of 554 samples were sequenced successfully, 348 from colonized, 201 from infected, and 5 from patients with unknown status. The NAP1/027/ST1 strain was most common among infected and colonized patients. Colonized patients predominantly carried toxigenic strains. Comparing samples from infected patients with all prior samples, a donor with a plausible ward link was found for 115 (57.2%) cases using PFGE, 127 (63.2%) using MLST, and 81 (40.3%) using WGS with a threshold of ≤2 single-nucleotide variants to determine relatedness. Examining data from the two hospitals with most complete data, across all typing methods, more cases could be linked to infected patients rather than to colonized patients. Using WGS, 26 (21.9%) cases were genetically linked to infected patients only, whereas 4 (3.4%) to colonized patients only, and 30 (25.2%) to both. Of those with a genetic link to an infected patient, 21 (17.7%) had a ward link, whereas this was found for only 1 (0.8%) case linked to a colonized patient. Conclusion Asymptomatic carriers contribute to transmission, but CDI cases are more likely linked to other infected patients than colonized patients in this cohort with high rates of NAP1/027/ST1 strain. Disclosures M. Wilcox, Merck & Co., Inc.: Consultant, Consulting fee. Cubist: Consultant, Grant Investigator and Speaker’s Bureau, Consulting fee, Grant recipient and Speaker honorarium. Alere, Actelion Pharma, Astellas, Optimer, Sanofi pasteur, Summit Pharma, bioMerieux, Da Volterra, Qiagen, Cerexa, Abbott, AstraZeneca, Pfizer, Durata Therapeutics, Seres Therapeutics, Valneva, Nabriva Therapeutics, Roche, The Medicines Company, Basilea P: Consultant, Consulting fee. Alere, Actelion Pharmaceuticals, Pharmaceuticals, Astellas, Optimer Pharmaceuticals, Sanofi pasteur, Summit Pharmaceuticals, bioMerieux, Da Volterra, Qiagen, Cerexa, and Abbott: Grant Investigator, Grant recipient.

Previously published guidelines are available that provide comprehensive recommendations for detecting and preventing healthcare-associated infections (HAIs). The intent of this document is to highlight practical recommendations in a concise format designed to assist acute care hospitals in implementing and prioritizing theirClostridium difficileinfection (CDI) prevention efforts. This document updates “Strategies to PreventClostridium difficileInfections in Acute Care Hospitals,” published in 2008. This expert guidance document is sponsored by the Society for Healthcare Epidemiology of America (SHEA) and is the product of a collaborative effort led by SHEA, the Infectious Diseases Society of America (IDSA), the American Hospital Association (AHA), the Association for Professionals in Infection Control and Epidemiology (APIC), and The Joint Commission, with major contributions from representatives of a number of organizations and societies with content expertise. The list of endorsing and supporting organizations is presented in the introduction to the 2014 updates.

OBJECTIVE: Helicobacter pylori (H. pylori) is a recognized pathogen, but it may also have a protective effect for gastroesophageal reflux disease (GERD). We compared the prevalence of potential virulence factors (cagA, cagE, vacA genotypes) in GERD to other upper gastrointestinal diseases and controls. METHODS: A total of 405 patients underwent gastroscopy with H. pylori isolation and serum testing. Patient diagnostic subgroups were prospectively defined. Genotypes were determined by amplification using polymerase chain reaction. CagA antibodies were determined by western blot, enzyme-linked immunosorbent, and flow microsphere immunofluorescent assays. RESULTS: Patients were grouped as follows: nonulcer dyspepsia (26%), GERD (20%), gastric ulcer (17%), duodenal ulcer (12%), gastric cancer (6%), or controls (19%). The cagA gene was present in 94–97% of subjects in all categories, but the cagA antibody was less prevalent in nonulcer dyspepsia (69%, 95% CI: 48–86%, p = 0.02) and GERD (69%, CI: 39–91%, p CONCLUSIONS: The cagE and vacA S1 genotypes are more prevalent in patients with peptic ulcer or gastric cancer, suggesting a potential function in virulence for these genes. However, the vacA S1 genotype was also more prevalent in controls than GERD, suggesting a potential protective effect against GERD.

Clostridium difficile isolates from a 2004 outbreak in Québec, Canada, were all found to be susceptible to metronidazole, vancomycin, rifampin, and meropenem but resistant to bacitracin, cefotaxime, ciprofloxacin, and levofloxacin, and most (>80%) were resistant to ceftriaxone, clarithromycin, gatifloxacin, and moxifloxacin. The predominant NAP1 isolates were susceptible to clindamycin, while the NAP2 isolates were resistant.

Background. Gold standard methods of detection of Helicobacter pylori are expensive, difficult to perform, or not widely available. The purpose of this study was to assess hematoxylin and eosin staining of antral tissue, a relatively inexpensive and widely available method of H. pylori detection. Materials and Methods. The hematoxylin and eosin stain was assessed as a method of H. pylori detection, with 2 × 2 table analysis using culture as the gold standard in 133 gastric biopsy specimens obtained from patients both before and following attempted eradication. Results. Performance of the stain was good among untreated patients as well as among patients having previously undergone an eradication treatment, with an overall accuracy of 92% (95% confidence intervals: 86–96), sensitivity of 93% (87–97), and specificity of 87% (69–96). Conclusion. The hematoxylin and eosin stain is an inexpensive method of H. pylori detection but with test performance characteristics inferior to Giemsa, Genta, or silver stains.

Objective: To determine the incidence of aspergillosis in patients with leukemia or bone marrow transplants during a construction-associated outbreak, and the effect of an environmental control program for Aspergillus.Design: Clinical, microbiological, and pathological records were reviewed retrospectively once the outbreak was appreciated, and prospectively thereafter, to determine the presence or absence of aspergillosis and duration of neutropenia.Setting: A university tertiary-care center with a single designated hematology-oncology unit.Patients: From January 1988 to September 1993, there were 141 patients with leukemia or bone marrow transplants identified as being neutropenic during 231 admissions to this specialized unit.Interventions: Installation of wall-mounted portable high-efficiency particulate air (HEPA)-filter air purifiers, application of copper-8-quinolinolate–formulated paint, replacement of perforated ceiling tiles with nonperforated type, sealing of all windows, replacement of horizontal, dust-accumulating blinds with vinyl, opaque, roller shades, and systematic and regular cleaning of surfaces.Results: Thirty-six cases of nosocomial aspergillosis were diagnosed during this period. The incidence density (ID) in the preconstruction period was 3.18 per 1,000 days at risk. During construction activity—before the implementation of a control strategy—the ID increased dramatically to 9.88 per 1,000 days at risk. With infection control measures implemented and continued construction work, the ID decreased to 2.91 per 1,000 days at risk, comparable to the preconstruction baseline rate.Conclusions: An environmental control strategy incorporating widely available technology may have played an important role in controlling this outbreak of construction-associated invasive aspergillosis.

To explore the use of the Risk Assessment and Predictor Tool (RAPT) as a pre-operative tool to predict postoperative discharge destination and length of stay for patients undergoing total knee replacement (TKR) in Singapore.A cohort of 569 patients undergoing primary TKR at the Singapore General Hospital were recruited prospectively from November 2009 to June 2010.All patients completed a modified RAPT questionnaire pre-operatively, and underwent standard clinical pathway guidelines for TKR throughout the study.Actual discharge destination (ADDest) and length of stay (LOS).Total RAPT score and preferred discharge destination (PDD) were recorded pre-operatively, while ADDest and LOS were obtained immediately after discharge. Multivariable logistic regression and multivariable regression analysis were used to determine whether the RAPT items and score could predict the discharge outcomes.Total RAPT score was a significant predictor of LOS for patients following TKR (R=0.24, P0.001); the higher the RAPT score, the longer the LOS. Total RAPT score was also a significant predictor of actual discharge to home [odds ratio (OR) 2.32, 95% confidence interval (CI) 1.11 to 4.85]. PDD was a significant predictor for LOS (R=0.22, P0.001) and ADDest (R=0.33, P0.001). Patients who chose to be discharged home were more likely to be directly discharged home (OR 9.79, 95% CI 5.07 to 18.89, P0.001).Total RAPT score and PDD were significant predictors of ADDest and LOS for patients following TKR in Singapore. The ability to predict discharge outcomes following TKR could assist caregivers, healthcare professionals and administrators in optimising care and resource allocations for patients.

Organisms expressing Klebsiella pneumoniae carbapenemase (KPC) are found in several regions worldwide but are rarely detected in Canada. The first outbreak of KPC-expressing strains of Enterobacteriaceae clinical isolates in a university-affiliated hospital intensive care unit (ICU) in Canada is described.Enterobacteriaceae isolates that were flagged by the Vitek 2 (bioMérieux, France) system as possible carbapenemase producers were subjected to the modified Hodge test. Modified Hodge test-positive organisms were analyzed by pulsed-field gel electrophoresis, tested for KPC and other beta-lactamase genes by polymerase chain reaction analysis and underwent subsequent nucleic acid sequencing. Antimicrobial susceptibility profiles were determined by Vitek 2 and Etest (bioMérieux, France). A chart review was conducted to establish epidemiological links.During the study period, 10 unique Enterobacteriaceae isolates expressing KPC were detected from nine ICU patients. Five patients had infections (three pneumonias, one surgical site infection, one urinary tract infection). Isolates included Escherichia coli (5), Klebsiella oxytoca (2), Serratia marcescens (2) and Citrobacter freundii (1). Polymerase chain reaction analysis and sequencing confirmed the presence of KPC-3 in all isolates; four also carried TEM, two CTX-M and one CMY-2. The imipenem minimum inhibitory concentrations as determined by Etest ranged from 0.75 μg/mL to ≥32 μg/mL. Pulsed field gel electrophoresis clonal patterns and patient location in the ICU revealed presumptive horizontal transmission events.In the present study, Enterobacteriaceae isolates with KPC are emerging and can result in serious infections. The KPC gene can spread via plasmids to different genera of the Enterobacteriaceae family. The dissemination of KPC in Enterobacteriaceae and the consequences for treatment and infection control measures warrant a high degree of vigilance among clinicians and microbiologists.On trouve des organismes producteurs de carbapénèmases de typeLes chercheurs ont soumis au test de Hodge modifié les isolats d’entérobactéries que le système Vitek 2 (bioMérieux, France) signalait comme de possibles producteurs de carbapénèmases. Les chercheurs ont analysé les organismes positifs au test de Hodge par électrophorèse sur gel en champ pulsé, ont vérifié la présence de KPC et d’autres gènes de bêta-lactamase par analyse de la réaction en chaîne de la polymérase et ont ensuite effectué un séquençage de l’acide nucléique. Ils ont déterminé les profils de susceptibilité antimicrobienne par le système Vitek 2 et le test E (bioMérieux, France), puis procédé à une analyse des dossiers pour établir des liens épidémiologiques.Pendant la période de l’étude, les chercheurs ont décelé dix isolats uniques d’entérobactéries productrices de KPC chez neuf patients de l’USI. Cinq patients avaient une infection (trois pneumonies, une infection au foyer d’une opération, une infection urinaire). Les isolats incluaient l’Dans la présente étude, les isolats d’entérobactéries productrices de KPC sont émergents et peuvent donner lieu à de graves infections. Le gène de KPC peut se propager par les plasmides à divers genres de la famille des entérobactéries. La dissémination du KPC dans les entérobactéries et les conséquences pour les traitements et les mesures de contrôle des infections justifient un degré élevé de vigilance chez les cliniciens et les microbiologistes.

Patients in intensive care units (ICUs) often acquire infections, which impose a heavy human and financial burden. The use of private rooms may reduce the acquisition of certain pathogens, but the limited evidence on this topic is inconsistent.We compared the rates of acquisition of infectious organisms in an ICU before and after a change from multibed to single rooms. As a control, we used acquisition rates in the ICU of a nearby university teaching hospital, which contained both multibed and single rooms, during the study period. We used a statistical model to adjust for background time trends common to both hospitals.The adjusted rate of acquisition of Clostridium difficile, vancomycin-resistant Enterococcus species, and methicillin-resistant Staphylococcus aureus combined decreased by 54% (95% confidence interval [CI], 29%-70%) following the intervention. The methicillin-resistant S aureus acquisition rate fell by 47% (95% CI,1%-71%), the C difficile acquisition rate fell by 43% (95% CI, 7%-65%), and the yeast acquisition rate fell by 51% (95% CI, 34%-64%). Twelve common and likely exogenous organisms and exogenous/endogenous organisms had a reduction in acquisition rates after the intervention; for 6 of them, this reduction was statistically significant. No effect was observed on the acquisition rate of coagulase-negative Staphylococcus species, the most common endogenous organism, for which no change would be expected. The adjusted rate ratio of the average length of stay in the ICU was 10% (95% CI, 0%-19%) lower after the intervention.Conversion to single rooms can substantially reduce the rate at which patients acquire infectious organisms while in the ICU.

Bimodality in the frequency distribution of plasma glucose 2 h after a 75-g oral glucose challenge has been demonstrated in only a few population groups, and the generalizability of the phenomenon remains unclear. Therefore, we have studied the distribution of 2-h glucose in 1813 Micronesians, aged 20 years and over, from an urbanized community of the Pacific Ocean Republic of Kiribati. The 2-h plasma glucose distributions were consistent with a mixture model comprising two lognormal components for age groups 30–39, 40–49 and 50 + years. The parameters of the mixture distribution were estimated by the method of maximum likelihood. The prevalence of non-insulin-dependent diabetes mellitus was 7.3% as defined by World Health Organization diagnostic criteria, and 4.7% when defined according to age-specific optimal cut-off values based on the minimization of the total number of misclassified individuals. Assuming that the fitted mixture distribution for each age group was the true plasma glucose distribution, the sensitivity and specificity of the World Health Organization diagnostic criteria and the age-specific optimal cut-off values were determined. Higher sensitivity with relatively little impairment of specificity resulted with the use of the former criteria. The prevalence of non-insulin-dependent diabetes mellitus increased with age as did the mean and standard deviation of the lower lognormal glucose component (“nondiabetics”). However, the mean and standard deviation of the “diabetic” upper component remained relatively constant and varied little with age. Considered together with results from other studies, our findings suggest that bimodality of 2-h plasma glucose distributions is probably present in most populations, but the ability to demonstrate it is a function of the number of subjects for whom data are available, the proportion of subjects in the upper component of the distribution, and the method of assessing its presence.

In the world of infectious diseases, the confidence of the 1960s and 1970s has given way to a stark realization that our mastery of the microbial world is not absolute — as the emergence of SARS and of avian influenza has illustrated. The current outbreak of Clostridium difficile associated

Susceptibility testing was performed at seven Canadian microbiology laboratories and the Helicobacter Reference Laboratory, Halifax, Nova Scotia, Canada, to assess susceptibility testing proficiency and the reproducibility of the results for clarithromycin and metronidazole and to compare the Epsilometer test (E test) method to the agar dilution reference method. Control strain Helicobacter pylori ATCC 43504 (American Type Culture Collection) and 13 clinical isolates (plus duplicates of four of these strains including ATCC 43504) were tested blindly. The National Committee for Clinical Laboratory Standards (NCCLS) guidelines for agar dilution testing were followed, and the same suspension of organisms was used for agar dilution and E test. Antimicrobials and E test strips were provided to the investigators. Methods were provided on a website ( www.Helicobactercanada.org ). Each center reported MICs within the stated range for strain ATCC 43504. Compared to the average MICs, interlaboratory agreements within 2 log 2 dilutions were 90% (range, 69 to 100%) for clarithromycin by agar dilution, with seven very major errors [VMEs], and 85% (range, 65 to 100%) by E test, with three VMEs. Interlaboratory agreements within 2 log 2 dilutions were 83% (range, 50 to 100%) for metronidazole by agar dilution, with six VMEs and eight major errors (MEs), and 75% (range, 50 to 94%) by E test, with four VMEs and four MEs. At lower and higher concentrations of antibiotic, E test MICs were slightly different from agar dilution MICs, but these differences did not result in errors. When a standardized protocol based on NCCLS guidelines was used, most participants in this study correctly identified clarithromycin- and metronidazole-susceptible and -resistant strains of H. pylori 93% of the time by either the agar dilution or E test method, and the numbers of errors were relatively equivalent by both methods.

In the province of Quebec, Canada, from 1996 to 1998, 3,650 invasive Streptococcus pneumoniae infections were reported. A total of 1,354 isolates were serotyped and tested for antimicrobial susceptibility. The distribution of serotypes remained stable over the 3 years, with serotypes 14, 6B, 4, 9V, 23F, and 19F accounting for 61% of the isolates. Overall, 90% of isolates were included in the current 23-valent vaccine and 67% were included in the 7-valent conjugate vaccine. We were able to determine that resistance to penicillin and to other antibiotics is increasing.

OBJECTIVES: A recent report has suggested an association between Helicobacter pylori eradication and the development of gastroesophageal reflux disease (GERD). We therefore assessed the incidence of GERD among comparable patients having undergone successful versus failed H. pylori eradication in a controlled trial. We also compared the H. pylori strains in the subjects that developed GERD to those that did not. METHODS: Patients with a history of proven duodenal ulcer and H. pylori infection were randomised into a H. pylori eradication study. Patients subsequently underwent gastroscopy with gastric biopsies every 3 months for 1 yr. At each visit, the presence of GERD symptoms and endoscopic esophagitis were noted, and the incidence of these variables among patients in whom H. pylori eradication was successful was compared to those in whom it was not. In a subgroup, the presence of the cagA, cagE, and vacA genotypes and of cagA antibodies were determined. RESULTS: Of 98 patients randomized into this study, 11 dropped out before determination of H. pylori eradication, leaving 87 patients with analyzable results. H. pylori eradication was successful in 63 (72%). By the end of the follow-up period, patients with GERD symptoms or endoscopic esophagitis were more prevalent in the successful than in the failed eradication group (37% [95% CI: 25–50%] vs 13% [95% CI: 3–32%], p = 0.04, 95% CI for the difference: 6–42%), as were patients with GERD symptoms alone (29% [95% CI: 18–41%] vs 8% [95% CI: 1–27%], p = 0.04, 95% CI for the difference: 4–36%) or esophagitis alone (21% [95% CI: 12–33%] vs 4% [95% CI: 0–21%], p = 0.10, 95% CI for the difference: 4–29%, respectively). Multivariate analysis revealed no significant association between the incidence of symptoms or esophagitis and age, gender, Quetelet index, caffeine or alcohol intake, smoking, weight change, or the presence of a hiatus hernia. There were also no differences in the prevalence of H. pylori genotypes from patients who developed GERD as compared to those who did not. CONCLUSIONS: In this patient population, the incidence of new GERD-type symptoms or endoscopic esophagitis was greater in patients in whom successful eradication was achieved. This difference does not appear to be attributable to weight gain, habits, or specific H. pylori strains.