Burden of noninfluenza respiratory viral infections in adults admitted to hospital: analysis of a multiyear Canadian surveillance cohort from 2 centres.

BACKGROUND: Data on the outcomes of noninfluenza respiratory virus (NIRV) infections among hospitalized adults are lacking. We aimed to study the burden, severity and outcomes of NIRV infections in this population. METHODS: We analyzed pooled patient data from 2 hospital-based respiratory virus surveillance cohorts in 2 regions of Canada during 3 consecutive seasons (2015/16, 2016/17, 2017/18; n = 2119). We included patients aged ≥ 18 years who developed influenza-like illness or pneumonia and were hospitalized for management. We included patients confirmed positive for ≥ 1 virus by multiplex polymerase chain reaction assays (respiratory syncytial virus [RSV], human rhinovirus/enterovirus (hRV), human coronavirus (hCoV), metapneumovirus, parainfluenza virus, adenovirus, influenza viruses). We compared patient characteristics, clinical severity conventional outcomes (e.g., hospital length-of stay, 30-day mortality) and ordinal outcomes (5 levels: discharged, receiving convalescent care, acute ward or intensive care unit [ICU] care and death) for patients with NIRV infections and those with influenza. RESULTS: Among 2119 adults who were admitted to hospital, 1156 patients (54.6%) had NIRV infections (hRV 14.9%, RSV 12.9%, hCoV 8.2%) and 963 patients (45.4%) had influenza (n = 963). Patients with NIRVs were younger (mean 66.4 [standard deviation 20.4] yr), and more commonly had immunocompromising conditions (30.3%) and delay in diagnosis (median 4.0 [interquartile range (IQR) 2.0-7.0] days). Overall, 14.6% (12.4%-19.5%) of NIRV infections were acquired in hospital. Admission to ICU (18.2%, median 6.0 [IQR 3.0-13.0] d), hospital length-of-stay (median 5.0 [IQR 2.0-10.0] d) and 30-day mortality (8.4%; RSV 9.5%, hRV 6.6%, hCoV 9.2%) and the ordinal outcomes were similar for patients with NIRV infection and those with influenza. Age > 60 years, immunocompromised state and hospital-acquired viral infection were associated with worse outcomes. The estimated median cost per acute care admission was $6000 (IQR $2000-$16 000). INTERPRETATION: The burden of NIRV infection is substantial in adults admitted to hospital and associated outcomes may be as severe as for influenza, suggesting a need to prioritize therapeutics and vaccines for at-risk people.

The effect of sucrose addition at dosage stage on the foam attributes of a bottle-fermented English sparkling wine.

BACKGROUND: Approximately two-thirds of wine produced in the UK is bottle-fermented sparkling wine. Effervescence and foamability are key features used to assess English sparkling wine (ESW) quality. A critical, yet understudied, area of research is the potential for dosage to influence foam behaviour via associated changes in wine viscosity. RESULTS: In this study, dosage treatments of five increasing levels of sucrose (from 0 to 31 g L-1 ) were added to an ESW. After storage, the foamability attributes of the wines were analysed via an adapted Mosalux method and a novel image analysis method combined with free pour of the wine. Results indicate that increasing sucrose concentration improved foam formation, but reduced foam stability, likely due to the sucrose added causing a modification in wine viscosity. CONCLUSIONS: These results highlight the impact that dosage treatments can have on the quality of foam produced upon pouring, and therefore have the potential to inform future sparkling winemaking practices. © 2017 Society of Chemical Industry.

Small-signal analysis of microring resonator modulators.

We derive the frequency-dependent modulation transfer functions for microring resonator modulators, using a small-signal analysis. Modulation efficiencies are obtained in terms of familiar optical cavity parameters, which provide an intuitive understanding of device performance. The results are in good agreement with experimental data, and are used to compare operating characteristics between resonance-modulated and coupling-modulated microresonators.

Epidemiology and outcome of pneumonia caused by methicillin-resistant Staphylococcus aureus (MRSA) in Canadian hospitals.

BACKGROUND: MRSA remains a leading cause of hospital-acquired (HAP) and healthcare-associated pneumonia (HCAP). We describe the epidemiology and outcome of MRSA pneumonia in Canadian hospitals, and identify factors contributing to mortality. METHODS: Prospective surveillance for MRSA pneumonia in adults was done for one year (2011) in 11 Canadian hospitals. Standard criteria for MRSA HAP, HCAP, ventilator-associated pneumonia (VAP), and community-acquired pneumonia (CAP) were used to identify cases. MRSA isolates underwent antimicrobial susceptibility testing, and were characterized by pulsed-field gel electrophoresis (PFGE) and Panton-Valentine leukocidin (PVL) gene detection. The primary outcome was all-cause mortality at 30 days. A multivariable analysis was done to examine the association between various host and microbial factors and mortality. RESULTS: A total of 161 patients with MRSA pneumonia were identified: 90 (56%) with HAP, 26 (16%) HCAP, and 45 (28%) CAP; 23 (14%) patients had VAP. The mean (± SD) incidence of MRSA HAP was 0.32 (± 0.26) per 10,000 patient-days, and of MRSA VAP was 0.30 (± 0.5) per 1,000 ventilator-days. The 30-day all-cause mortality was 28.0%. In multivariable analysis, variables associated with mortality were the presence of multiorgan failure (OR 8.1; 95% CI 2.5-26.0), and infection with an isolate with reduced susceptibility to vancomycin (OR 2.5, 95% CI 1.0-6.3). CONCLUSIONS: MRSA pneumonia is associated with significant mortality. Severity of disease at presentation, and infection caused by an isolate with elevated MIC to vancomcyin are associated with increased mortality. Additional studies are required to better understand the impact of host and microbial variables on outcome.

Barriers and bridges to infection prevention and control: results of a qualitative case study of a Netherlands' surgical unit.

OBJECTIVES: The objectives of the study are to observe the overall work environment including infection prevention and control (IP&C) practices on the target surgical unit; to analyse the policies and procedures in the hospital and unit environments; to analyse the barriers and bridges to IP&C that practitioners identify in visual narratives of their unit environment and to collect monthly specific IP&C-related anonymised data. DESIGN: In this qualitative case study analysis, a socio-ecological approach on health systems informed the research design and provided a framework to better understand the complexity of implementing effective IP&C. SETTING: The study was conducted on a surgical unit at a Netherlands' hospital that reported successful reductions in the prevalence of targeted multidrug-resistant organisms. METHODS: Research methods included unit observations (n=3), review of relevant policies and procedures, five practitioner-led photo walkabouts of the unit (n=7), three photo elicitation focus groups with practitioners (n=13) and the review of related IP&C data. RESULTS: The findings indicate some conditions and processes present that may influence the low prevalence of multidrug-resistant organisms, including the 'search and destroy' active surveillance strategy, low occupancy rates, a centralised bed cleaning system and the presence of an active grass roots Hygiene in Practice group, which engages practitioners in several ongoing activities to promote IP&C on the units. CONCLUSIONS: Further research on the benefits of practitioner-led community of practices on IP&C practices such as the Hygiene in Practice group is also recommended. Additional case studies to compare theses practices with other acute care hospital around the world would be a valuable way to better understand what IP&C programmes are most effective in which contexts and for what reasons. Further data are available by contacting the primary author directly.

A point prevalence survey of health care-associated infections in Canadian pediatric inpatients.

BACKGROUND: Health care-associated infections (HAIs) cause considerable morbidity and mortality to hospitalized patients. The objective of this point prevalence study was to assess the burden of HAIs in the Canadian pediatric population, updating results reported from a similar study conducted in 2002. METHODS: A point prevalence survey of pediatric inpatients was conducted in February 2009 in 30 pediatric or combined adult/pediatric hospitals. Data pertaining to one 24-hour period were collected, including information on HAIs, microorganisms isolated, antimicrobials prescribed, and use of additional (transmission based) precautions. The following prevalent infections were included: pneumonia, urinary tract infection, bloodstream infection, surgical site infection, viral respiratory infection, Clostridium difficile infection, viral gastroenteritis, and necrotizing enterocolitis. RESULTS: One hundred eighteen patients had 1 or more HAI, corresponding to a prevalence of 8.7% (n = 118 of 1353, 95% confidence interval: 7.2-10.2). Six patients had 2 infections. Bloodstream infections were the most frequent infection in neonates (3.0%), infants (3.1%), and children (3.5%). Among all patients surveyed, 16.3% were on additional precautions, and 40.1% were on antimicrobial agents, whereas 40.7% of patients with a HAI were on additional precautions, and 89.0% were on antimicrobial agents. CONCLUSION: Overall prevalence of HAI in 2009 has remained similar to the prevalence reported from 2002. The unchanged prevalence of these infections nonetheless warrants continued vigilance on their prevention and control.

Molecular characterization of moxifloxacin resistance from Canadian Clostridium difficile clinical isolates.

Fluoroquinolone resistance in Clostridium difficile has been implicated in recent outbreaks of C. difficile infection. The purpose of this report was to characterize the molecular mechanism conferring resistance to moxifloxacin among C. difficile clinical isolates. Eighty-four C. difficile clinical isolates (collected as part of the Canadian Nosocomial Infection Surveillance Program) were evaluated in the current study. Pulsed-field gel electrophoresis was used to type the isolates. Susceptibility testing was performed using Clinical and Laboratory Standards Institute agar dilution methods. The quinolone resistance-determining region of both gyrA and gyrB was amplified using polymerase chain reaction and sequenced for each isolate. The proportion of isolates studied by the North American pulsed-field (NAP) type was as follows: NAP1 (47.6%), NAP2 (20.2%), NAP3 (5.9%), NAP4 (4.8%), NAP5 (2.4%), NAP6 (3.6%), and other patterns (15.5%). All isolates were resistant to ciprofloxacin. Among moxifloxacin-susceptible isolates (MIC < or =2 microg/mL), no amino acid substitutions were detected in either GyrA or GyrB. Three distinct amino acid substitutions were observed among the 3 isolates that had a moxifloxacin MIC of 8 microg/mL (GyrA Asp71 to Val, GyrB Asp426 to Asn, or Glu466 to Val). Isolates with a moxifloxacin MIC of 16 or 32 microg/mL (moderate-level resistance) all had a single identical amino acid substitution in GyrA (Thr82 to Ile). For isolates with a moxifloxacin MIC of > or =64 microg/mL (high-level resistance), this Thr82 to Ile substitution in GyrA was accompanied by at least 1 other amino acid substitution in either GyrA (Asp71 to Glu, Pro116 to Ala, or Ala118 to Ser) or GyrB (Ser366 to Ala, Asp426 to Asn, Asp426 to Val, or Leu444 to Phe) in all but 1 case. Moderate-level moxifloxacin resistance was associated with a single substitution in GyrA. High-level moxifloxacin resistance was associated with this GyrA substitution plus at least 1 other substitution in GyrA or GyrB.

Hypervirulent Clostridium difficile strains in hospitalized patients, Canada.

To determine the incidence rate of infections with North American pulsed-field types 7 and 8 (NAP7/NAP8) strains of Clostrodium difficile, ribotype 078, and toxinotype V strains, we examined data collected for the Canadian Nosocomial Infections Surveillance Program (CNISP) CDI surveillance project during 2004-2008. Incidence of human infections increased from 0.5% in 2004/2005 to 1.6% in 2008.

Acinetobacter baumannii in casualties returning from Afghanistan.

Military personnel returning from Afghanistan and entering Canadian hospitals may be infected with multidrug resistant Acinetobacter baumannii. The Public Health Agency of Canada, in conjunction with the Canadian Forces, have developed an alert to inform hospitals of the potential for importation of Acinetobacter baumannii, and the appropriate precautionary measures that should be taken to prevent secondary spread within hospitals.

Ralstonia pickettii bacteremia associated with pediatric extracorporeal membrane oxygenation therapy in a Canadian hospital.

We describe 2 pediatric patients with Ralstonia pickettii bacteremia associated with extracorporeal membrane oxygenation (ECMO) therapy. Investigation revealed a common environmental source--the ECMO temperature-control units. We created guidelines for disinfecting these units that do not void the manufacturer's warranty and have prevented additional cases of bacteremia due to this organism.

A point prevalence survey of health care-associated infections in pediatric populations in major Canadian acute care hospitals.

OBJECTIVE: To estimate the prevalence of pediatric health care-associated infections (HAI) in Canadian acute care hospitals. METHODS: A point-prevalence study conducted in February 2002 in 25 hospitals across Canada. Information on HAI, utilization of antimicrobial agents and invasive devices, isolation precautions, and microbial etiology was collected. RESULTS: Nine hundred ninety-seven children were surveyed. Ninety-one HAI were detected in 80 patients for a prevalence of 91 per 1000 patients surveyed. Bloodstream infections were the most common HAI (3% of patients; 34% of all HAI). The prevalence of patients with HAI was 8%, ranging from 0% in trauma/bum units to 19% in the pediatric intensive care units, and 27% in transplant units. By multivariate logistic regression analysis, having a central venous catheter (OR, 2.54; 95% CI, 1.46-4.40) or endotracheal tube with mechanical ventilation (OR, 2.59; 95% CI, 1.16-5.76) were independently associated with an HAI, as were being in isolation (OR, 2.90; 95% CI, 1.54-5.45), and receiving antimicrobial agents (OR, 9.27; 95% CI, 4.71-18.52). CONCLUSION: In this first national point-prevalence study in Canada, the prevalence of HAI was similar to that reported in other industrialized countries. These data will also be useful to provide an estimate of the health burden of pediatric HAI in Canada.

Histoplasmosis cluster, golf course, Canada.

We report a cluster of 4 cases of acute histoplasmosis (1 culture proven and 3 with positive serology, of which 2 were symptomatic) associated with exposure to soil during a golf course renovation. Patients in western Canada with compatible symptoms should be tested for histoplasmosis, regardless of their travel or exposure history.

Pediatric poststernotomy mediastinitis.

BACKGROUND: Mediastinitis results in significant morbidity in pediatric cardiac patients. It is not clear whether delayed sternal closure is a risk factor for these infections. Management of mediastinitis remains controversial. METHODS: Cases of mediastinitis at the Stollery Children's Hospital from January 1, 1991, to June 30, 2004, were reviewed. RESULTS: There were 29 cases of mediastinitis in 2,675 open cardiac procedures for an overall incidence of 1.1%. Infection was diagnosed 5 to 27 days after the original surgical procedure (median, 10 days). The odds ratio for infection with delayed sternal closure versus primary sternal closure was 1.88 (95% confidence interval, 0.63 to 5.60). Signs at the onset of infection included fever (86%), incisional erythema (69%), purulent drainage from the incision or pacer wire sites (83%), and wound dehiscence (23%). Debridement was followed by primary sternal closure in all but three cases in which the sternum had not been closed before debridement and rotational muscle flaps were not used. Continuous irrigation systems were used only in the first 7 patients. One patient died of mediastinitis complicated by infective endocarditis, and 2 patients died of multiorgan failure. CONCLUSIONS: Delayed sternal closure was not a major risk factor for mediastinitis, especially if primary skin closure was used with delayed sternal closure. Excellent results were attained with debridement and primary closure of these infections.

Nitrogen composition in urban runoff--implications for stormwater management.

A study was conducted to characterise the composition of nitrogen in urban stormwater in Melbourne, Australia, during baseflows and storm events, and to compare the results with international data. Nitrogen in Melbourne stormwater was predominantly dissolved (approximately 80%), with ammonia the least-abundant form (approximately 11%). Concentrations of nitrogen species did not vary significantly between baseflow and storms, although the proportion of nitrogen in particulate form was higher during storm events (p = 0.04). Whilst the composition of nitrogen in Melbourne was broadly consistent with international data, the level of dissolved inorganic nitrogen was higher in Melbourne (mu = 48% during baseflows and 49% during storms) than in the international literature (mu = 29%). Limitations in the international dataset precluded comparison of total dissolved nitrogen. The results have implications for stormwater management. Whilst nitrogen species concentrations are variable, they are not strongly related to flow conditions, so treatment systems must be designed to cope with stochastic inflow concentrations at all times. To optimise their performance, stormwater treatments should be designed to improve dissolved nitrogen removal. Further research is needed to improve the ability of treatment systems to achieve this aim.