Unusual Legionnaires' outbreak in cool, dry Western Canada: an investigation using genomic epidemiology.

An outbreak of Legionnaires' disease occurred in an inner city district in Calgary, Canada. This outbreak spanned a 3-week period in November-December 2012, and a total of eight cases were identified. Four of these cases were critically ill requiring intensive care admission but there was no associated mortality. All cases tested positive for Legionella pneumophila serogroup 1 (LP1) by urinary antigen testing. Five of the eight patients were culture positive for LP1 from respiratory specimens. These isolates were further identified as Knoxville monoclonal subtype and sequence subtype ST222. Whole-genome sequencing revealed that the isolates differed by no more than a single vertically acquired single nucleotide variant, supporting a single point-source outbreak. Hypothesis-based environmental investigation and sampling was conducted; however, a definitive source was not identified. Geomapping of case movements within the affected urban sector revealed a 1·0 km common area of potential exposure, which coincided with multiple active construction sites that used water spray to minimize transient dust. This community point-source Legionnaires' disease outbreak is unique due to its ST222 subtype and occurrence in a relatively dry and cold weather setting in Western Canada. This report suggests community outbreaks of Legionella should not be overlooked as a possibility during late autumn and winter months in the Northern Hemisphere.

Decline in Decreased Cephalosporin Susceptibility and Increase in Azithromycin Resistance in Neisseria gonorrhoeae, Canada.

Antimicrobial resistance profiles were determined for Neisseria gonorrhoeae strains isolated in Canada during 2010-2014. The proportion of isolates with decreased susceptibility to cephalosporins declined significantly between 2011 and 2014, whereas azithromycin resistance increased significantly during that period. Continued surveillance of antimicrobial drug susceptibilities is imperative to inform treatment guidelines.

Comparison of Two Different Programmes of Ovulation Synchronization in the Treatment of Ovarian Cysts in Dairy Cows.

It was the aim of this field study to evaluate two different protocols of ovulation synchronization for the treatment of ovarian cysts and their effect on reproductive performance in dairy cows. In addition, factors with a possible influence on treatment success and pregnancy outcome as well as costs per pregnancy were analysed. The study was performed with 130 German Holsteins with ovarian cysts diagnosed on days 55 to 60 postpartum. Cows belonging to group 1 (n = 65) received a modified ovsynch protocol [day 0: 0.15 mg cloprostenol (PGF) + 0.02 mg buserelin acetate (GnRH); day 14: PGF; day 16: GnRH]. Group 2 (n = 65) was treated with the conventional ovsynch protocol (day 0: GnRH; day 7: PGF; day 9: GnRH). Timed artificial insemination was performed 20 to 24 h later. Cows without ovarian cysts served as controls. Treatment success (disappearance of the ovarian cyst) after the first ovsynch cycle was higher in group 1 (66.2%) than in group 2 (23.1%, p < 0.05). Reproductive measures in group 1 were comparable with those of the control group and, compared with group 2, were conspicuously better (66.2%, 76.9%, 83.1%, 59.5% vs. 40.0%, 50.7%, 60.0%, 27.5% for cumulative pregnancy rate after treatment cycle 1 to 3 and second service conception rate, respectively, p < 0.05). Overconditioned cows and cows with larger ovarian cysts showed a diminished treatment and pregnancy success. In group 1, costs per pregnancy were only slightly higher than in the control group (group 1: €352.44, group 2: €484.59, control group: €333.77). In conclusion, our results suggest that ovsynch protocols can be used in the treatment of ovarian cysts. The modified ovsynch protocol led to a better cure rate as well as a better reproductive performance, and was economically beneficial compared with a conventional ovsynch protocol.

Dielectric constant and low-frequency infrared spectra for liquid water and ice Ih within the E3B model.

Two intrinsic difficulties in modeling condensed-phase water with conventional rigid non-polarizable water models are: reproducing the static dielectric constants for liquid water and ice Ih, and generating the peak at about 200 cm(-1) in the low-frequency infrared spectrum for liquid water. The primary physical reason for these failures is believed to be the missing polarization effect in these models, and consequently various sophisticated polarizable water models have been developed. However, in this work we pursue a different strategy and propose a simple empirical scheme to include the polarization effect only on the dipole surface (without modifying a model's intermolecular interaction potential). We implement this strategy for our explicit three-body (E3B) model. Our calculated static dielectric constants and low-frequency infrared spectra are in good agreement with experiment for both liquid water and ice Ih over wide temperature ranges, albeit with one fitting parameter for each phase. The success of our modeling also suggests that thermal fluctuations about local minima and the energy differences between different proton-disordered configurations play minor roles in the static dielectric constant of ice Ih. Our analysis shows that the polarization effect is important in resolving the two difficulties mentioned above and sheds some light on the origin of several features in the low-frequency infrared spectra for liquid water and ice Ih.

Prevalence of Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) in food samples associated with foodborne illness in Alberta, Canada from 2007 to 2010.

Consumption of foods containing Staphylococcus aureus can cause severe gastro-intestinal illness. Given the fact that over the past decade, Canada has seen increasing rates of methicillin-resistant S. aureus (MRSA) carriage and infection, the objective of this study was to investigate the impact of methicillin-susceptible S. aureus (MSSA) and MRSA on foodborne illness in Alberta, Canada. Between January 2007 and December 2010, there were 693 food samples associated with foodborne investigations submitted to the Alberta Provincial Laboratory for Public Health (ProvLab). These foods were screened for: Bacillus cereus, Clostridium perfringens, S. aureus, Aeromonas spp., Campylobacter spp., Escherichia coli O157:H7, Salmonella, Shigella spp., and Yersinia spp. S. aureus was identified in 10.5% (73/693) of samples, and of these, 59% (43/73) were co-contaminated with at least one other organism on the screening panel. The S. aureus positive samples included 29 meat, 20 prepared foods containing meat, 11 prepared foods not containing meat, 10 dairy, and three produce. Methicillin-resistance was not detected in any isolates tested. These findings indicate that the presence of S. aureus in food associated with foodborne investigations is a cause for concern, and although MRSA was not found, the potential for outbreaks exists, and ongoing surveillance should be sustained.

Novel duplex real-time PCR assay detects Bordetella holmesii in specimens from patients with Pertussis-like symptoms in Ontario, Canada.

Bordetella holmesii is a human pathogen found mainly in immunocompromised patients. A specific real-time PCR assay was developed and successfully used to identify specimens from which B. holmesii was misidentified as Bordetella pertussis and to establish the prevalence of B. holmesii in Ontario patients with pertussis-like symptoms.

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.

Influenza increases invasive meningococcal disease risk in temperate countries.

OBJECTIVES: Invasive meningococcal disease (IMD) is a severe bacterial infection that displays wintertime seasonality in temperate countries. Mechanisms driving seasonality are poorly understood and may include environmental conditions and/or respiratory virus infections. We evaluated the contribution of influenza and environmental conditions to IMD risk, using standardized methodology, across multiple geographical regions. METHODS: We evaluated 3276 IMD cases occurring between January 1999 and December 2011 in 11 jurisdictions in Australia, Canada, France and the United States. Effects of environmental exposures and normalized weekly influenza activity on IMD risk were evaluated using a case-crossover design. Meta-analytic methods were used to evaluate homogeneity of effects and to identify sources of between-region heterogeneity. RESULTS: After adjustment for environmental factors, elevated influenza activity at a 2-week lag was associated with increased IMD risk (adjusted odds ratio (OR) per standard deviation increase 1.29; 95% confidence interval, 1.04-1.59). This increase was homogeneous across the jurisdictions studied. By contrast, although associations between environmental exposures and IMD were identified in individual jurisdictions, none was generalizable. CONCLUSIONS: Using a self-matched design that adjusts for both coseasonality and case characteristics, we found that surges in influenza activity result in an acute increase in population-level IMD risk. This effect is seen across diverse geographic regions in North America, France and Australia. The impact of influenza infection on downstream meningococcal risk should be considered a potential benefit of influenza immunization programmes.

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.

Differential patterns of amantadine-resistance in influenza A (H3N2) and (H1N1) isolates in Toronto, Canada.

BACKGROUND: Molecular methods were used to characterize influenza A (H1N1) and (H3N2) strains and to identify amantadine-resistance. OBJECTIVES: To compare proportions of amantadine-resistant influenza A (H1N1) and (H3N2) isolates in the Greater Toronto Area. STUDY DESIGN: Isolates of influenza A (H1N1) and (H3N2) were strain typed using molecular methods. Pyrosequencing for point mutations in the transmembrane domain of the M2 proton channel was undertaken. Proportions of amantadine-resistant and susceptible isolates were compared using the The Fisher's exact test. RESULTS: 96% of the 49 influenza A (H3N2) isolates and none of the influenza A (H1N1) tested carried a point mutation in the M gene coding for the M2 protein. Influenza A (H3N2) isolates were more likely to carry an amantadine-resistance associated mutation than influenza A (H1N1) isolates (Fishers's exact test, P<0.0001). CONCLUSIONS: : Characterization of amantadine-resistance in influenza A (H1N1) isolates should utilize a variety of different methods including sub-typing, strain typing, and direct sequencing for point mutations associated with amantadine-resistance.

Relationship between enteric pathogens and acute gastroenteritis disease severity: a prospective cohort study.

OBJECTIVES: To evaluate the relationship between individual bacterial and viral pathogens and disease severity. METHODS: Children <18 years with three or more episodes of vomiting and/or diarrhoea were enrolled in two Canadian paediatric emergency departments between December 2014 and August 2016. Specimens were analysed employing molecular panels, and outcome data were collected 14 days after enrolment. The primary outcome was severe disease over the entire illness (symptom onset until 14-day follow-up), quantified employing the Modified Vesikari Scale (MVS) score. The score was additionally analysed in two other time periods: index (symptom onset until enrolment) and follow-up (enrolment until 14-day follow-up). RESULTS: Median participant age was 20.7 (IQR: 11.3, 44.2) months; 47.4% (518/1093) and 73.4% (802/1093) of participants had index and total MVS scores ≥11, respectively. The most commonly identified pathogens were rotavirus (289/1093; 26.4%) and norovirus (258/1093; 23.6%). In multivariable analysis, severe disease over the entire illness was associated with rotavirus (OR = 9.60; 95%CI: 5.69, 16.19), Salmonella (OR = 6.61; 95%CI: 1.50, 29.17), adenovirus (OR = 2.53; 95%CI: 1.62, 3.97), and norovirus (OR = 1.43; 95%CI: 1.01, 2.01). Pathogens associated with severe disease at the index visit were: rotavirus only (OR = 6.13; 95%CI: 4.29, 8.75), Salmonella (OR = 4.59; 95%CI: 1.71, 12.29), adenovirus only (OR = 2.06; 95%CI: 1.41, 3.00), rotavirus plus adenovirus (OR = 3.15; 95%CI: 1.35, 7.37), and norovirus (OR = 0.68; 95%CI: 0.49, 0.94). During the follow-up period, rotavirus (OR = 2.21; 95%CI: 1.50, 3.25) and adenovirus (OR = 2.10; 95%CI: 1.39, 3.18) were associated with severe disease. CONCLUSIONS: In children presenting for emergency department care with acute gastroenteritis, pathogens identified were predominantly viruses, and several of which were associated with severe disease. Salmonella was the sole bacterium independently associated with severe disease.

Use of Bordetella pertussis BP3385 to establish a cutoff value for an IS481-targeted real-time PCR assay.

This study utilized the Bordetella pertussis single-copy PCR target BP3385 as a means of confirming IS481 PCR-positive reactions with cycle threshold (C(T)) values of >35. IS481 PCRs with C(T) values of >35 cycles may represent PCR conditions where there is <1 CFU of B. pertussis per PCR.

Surveillance summary of hospitalized pediatric enterovirus D68 cases in Canada, September 2014.

BACKGROUND: Enterovirus D68 (EV-D68) has been detected infrequently and has not been associated with severe disease in Canada. In the early fall of 2014, following an unusual case increase in the United States, clusters of EV-D68 among children and some adults manifesting severe symptoms were reported in Canada. OBJECTIVE: To provide an initial epidemiological summary of pediatric cases hospitalized with EV-D68 in Canada. METHODS: A time-limited surveillance pilot was conducted collecting information on pediatric cases (less than 18 years of age) hospitalized with EV-D68 between September 1 and 30, 2014. RESULTS: In total, 268 cases were reported from Ontario (n=210), Alberta (n=45), and British Columbia (n=13). Of the 268 reported cases, 64.9% (n=174) were male; the sex difference was statistically significant (p<0.01). Age was reported for 255 cases, with a mean age for males of 5.4 years and for females of 5.3 years. For cases with data available, 6.8% (18/266) were admitted to an intensive care unit. Of those where clinical illness was recorded, respiratory illness alone was present in 98.3% (227/231), neurologic illness alone was present in 0.4% (n=1), and both illnesses were present in 0.9% of cases (n=2); cases with neither respiratory nor neurologic illness were rare (n=1). Of the 90 cases with additional clinical information available, 43.3% were reported as having asthma. No deaths were reported among the 268 cases. CONCLUSION: The EV-D68 outbreak in Canada in September 2014 represents the beginning of a novel outbreak associated with severe illness in children. These findings provide the first epidemiological summary of severe cases of EV-D68 as an emergent respiratory pathogen in Canada. The continued investigation of this pathogen is necessary to build on these results and capture the full spectrum of associated illness.

A protein kinase inhibitor as an antimycobacterial agent.

The protein kinase inhibitor 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H7) was found to inhibit the growth of two different mycobacterial strains, the slow-growing Mycobacterium bovis Bacille Calmette Guerin (BCG) and the fast-growing saprophyte Mycobacterium smegmatis mc2 155, in a dose-dependent manner. While screening for the effect of kinase inhibitors on mycobacterial growth, millimolar concentrations of H7 induced a 40% decrease in the growth of M. bovis BCG when measured as a function of oxidative phosphorylation. This H7-induced decrease in growth was shown to involve a 2-log fold decrease in the viable counts of M. smegmatis within a 48-h period and a 50% reduction in the number of BCG viable counts within a 10-day period. Micromolar concentrations of H7 compound induced a significant decrease in the activity of the Mycobacterium tuberculosis protein serine/threonine kinase (PSTK) PknB. The inhibition of mycobacterial growth as well as the inhibition of a representative M. tuberculosis protein serine/threonine kinase PknB suggests that conventional PSTK inhibitors can be used to study the role that the mycobacterial PSTK family plays in controlling bacterial growth.

Surveillance and molecular characterization of non-tuberculous mycobacteria in a hospital water distribution system over a three-year period.

A three-year surveillance of non-tuberculous mycobacteria (NTM) in a hospital water distribution system was conducted at a facility located in southern Alberta. NTM was not present in any intake water samples, but was found in 106/183 (58%) of endpoint samples across 15 sites over the study period. Two different species of NTM were identified, Mycobacterium gordonae (88/183) and Mycobacterium avium (34/183); with only one strain of each M. gordonae and M. avium found. Given the sensitive nature of a healthcare facility, attention should be paid to minimize potential impact of NTM from potable water sources on patient health.

Evaluation of multiple commercial molecular and conventional diagnostic assays for the detection of respiratory viruses in children.

This study compares the performance of four commercial multiplex PCR assays (Resplex II Panel v2.0, Seeplex RV15, xTAG RVP and xTAG RVP Fast) and direct fluorescent antibody (DFA) staining and viral isolation. Seven hundred and fifty nasopharyngeal swabs were tested for 17 viral agents. In each assay, the sensitivity and specificity for each target were determined against a composite reference standard. Two hundred and eighty-eight out of 750 (38.4%) specimens were positive by DFA or viral isolation, while an additional 214 (28.5%) were positive by multiplex PCR, for a total positivity rate of 66.9%. Of 502 positive specimens, one virus was detected in 420 specimens (83.7%), two in 77 (15.3%), three in four (0.8%) and four in one case (0.2%). Compared with a composite reference standard, the inter-assay accuracy of the multiplex PCR assays varied, but all were superior to conventional diagnostic methods in detecting a broad range of respiratory viral agents in children. In addition, the sensitivity of two commercial assays, Resplex II Plus PRE and Seeplex Influenza A/B Subtyping, was determined relative to the Astra influenza Screen & Type assay for detection of influenza A viruses, including seasonal influenzas and pandemic H1N1 2009 influenza A virus. Using 75 positive and 55 negative nasopharyngeal swabs for influenza A by the Astra assay, the sensitivity of Seeplex and Resplex was 95.9% and 91.8%, respectively, with a specificity of 100% for both.

Surveillance of autopsy cases for D222G substitutions in haemagglutinin of the pandemic (H1N1) 2009 virus in Alberta, Canada.

Pandemic (H1N1) 2009 virus-positive specimens were collected from autopsy patients and matched to pandemic (H1N1) 2009 virus-positive nasopharyngeal specimens from community control patients and pandemic (H1N1) 2009 virus-positive specimens from intensive-care unit (ICU) patients. Specimens were analysed for polymorphisms at amino acid 222 of the haemagglutinin (HA) glycoprotein. Whereas some specimens from autopsy patients were positive for D222N, none was positive for D222G. All control patient specimens were wild-type D222. D222G polymorphisms were also identified in a subset of ICU patients with admixtures of D222G and D222 and of D222N, D222G and D222 present. The relevance of D222N and D222G to influenza pathogenesis and transmissibility currently remains unclear.