Cadham Provincial Laboratory

Winnipeg, Canada

Cadham Provincial Laboratory

Winnipeg, Canada
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Fanella S.,University of Manitoba | Kadkhoda K.,Cadham Provincial Laboratory | Shuel M.,National Microbiology Laboratory | Tsang R.,National Microbiology Laboratory
Emerging Infectious Diseases | Year: 2012

Endemic (nonvenereal) syphilis is relatively common in nonindustrialized regions of the world. We describe a case of local transmission in Canada and review tools available for confirming a diagnosis. Improved molecular tools and global clinical awareness are needed to recognize cases of endemic syphilis imported to areas where it is not normally seen.

Andonov A.,Public Health Agency of Canada | Kadkhoda K.,Cadham Provincial Laboratory | Osiowy C.,Public Health Agency of Canada | Kaita K.,University of Manitoba
Canadian Journal of Gastroenterology | Year: 2013

BACKGROUND: Traditional therapy with pegylated interferon and ribavirin combined with the new protease inhibitors boceprevir or telaprevir has demonstrated improved outcomes in hepatitis C virus (HCV)-infected patients. Prevalence data regarding pre-existing drug-resistant variants to these two new virus inhibitors in the Canadian population are not available. OBJECTIVE: To detect pre-existing mutations conferring resistance to boceprevir and/or telaprevir in Canadian patients infected with HCV genotype 1a. METHODS: Resistance-associated mutations (RAMs) were evaluated in 85 patients infected with HCV genotype 1a who had not yet received antiviral therapy. The NS3 protease gene was sequenced and common RAMs were identified based on a recently published list. RESULTS: The overall prevalence of pre-existing RAMs to boceprevir and telaprevir was higher compared with other similar studies. All of the observed RAMs were associated with a low level of resistance. A surprisingly high proportion of patients had the V55A RAM (10.6%). None of the mutations associated with a high level of resistance were observed. The simultaneous presence of two low-level resistance mutations (V36L and V55A) was observed in only one patient. Three other patients had both T54S RAM and V55I mutations, which may require a higher concentration of the protease drugs. The prevalence of various mutations in Aboriginal Canadian patients was higher (37.5%) compared with Caucasians (16.39%) (P=0.038). CONCLUSIONS: The present study was the first to investigate preexisting drug resistance to boceprevir/telaprevir in Canadian HCV-infected patients. A relatively high proportion of untreated HCV genotype 1a patients in Manitoba harbour low-level RAMs, especially patients of Aboriginal descent, which may contribute to an increased risk of treatment failure. ©2013 Pulsus Group Inc. All rights reserved.

Wylie J.L.,Cadham Provincial Laboratory | Van Caeseele P.,Cadham Provincial Laboratory | Gilmour M.W.,Public Health Agency of Canada | Sitter D.,Cadham Provincial Laboratory | And 2 more authors.
Journal of Clinical Microbiology | Year: 2013

This study assesses the detection performance of CHROMagar STEC medium relative to a reference cytotoxin assay and describes the current relative prevalence of O157 and non-O157 Shiga toxin-producing Escherichia coli (STEC) serotypes within the province of Manitoba, Canada. Over a 10-month period, 205 nonfrozen routine stool submissions to Cadham Provincial Laboratory (CPL) were used to assess the performance of CHROMagar STEC. Of the 205 stools, 14 were identified as true positives by a cytotoxin assay, with resultant CHROMagar STEC sensitivity, specificity, and positive predictive and negative predictive values of 85.7%, 95.8%, 60.0%, and 98.9%, respectively. Using a separate panel of 111 STEC strains, CHROMagar STEC was shown to support the growth of 96 (86.5%) isolates. To assess relative prevalence, attempts were made to isolate by any means all STEC strains identified at CPL over a 17-month period. Of 49 isolates (representing 86.0% of all STEC infections detected), only 28.6% were O157 STEC strains. Of the 35 non-O157 STEC strains, 29 were subjected to further molecular analysis. In contrast to earlier results from our area, carriage of stx2 appears to have increased. Overall, although CHROMagar STEC is not recommended as a primary screen, our results indicate that it is an effective supplemental medium for the isolation of probable STEC strains. Increased isolation of these serotypes is warranted to better understand their prevalence, clinical characteristics, and epidemiology and aid in the development or enhancement of food safety control programs targeting all STEC serotypes. Copyright © 2013, American Society for Microbiology.

Wylie J.L.,University of Manitoba | Wylie J.L.,Cadham Provincial Laboratory | Jolly A.M.,Public Health Agency of Canada
BMC Medical Research Methodology | Year: 2013

Background: Respondent driven sampling (RDS) was designed for sampling "hidden" populations and intended as a means of generating unbiased population estimates. Its widespread use has been accompanied by increasing scrutiny as researchers attempt to understand the extent to which the population estimates produced by RDS are, in fact, generalizable to the actual population of interest. In this study we compare two different methods of seed selection to determine whether this may influence recruitment and RDS measures. Methods. Two seed groups were established. One group was selected as per a standard RDS approach of study staff purposefully selecting a small number of individuals to initiate recruitment chains. The second group consisted of individuals self-presenting to study staff during the time of data collection. Recruitment was allowed to unfold from each group and RDS estimates were compared between the groups. A comparison of variables associated with HIV was also completed. Results: Three analytic groups were used for the majority of the analyses-RDS recruits originating from study staff-selected seeds (n = 196); self-presenting seeds (n = 118); and recruits of self-presenting seeds (n = 264). Multinomial logistic regression demonstrated significant differences between the three groups across six of ten sociodemographic and risk behaviours examined. Examination of homophily values also revealed differences in recruitment from the two seed groups (e.g. in one arm of the study sex workers and solvent users tended not to recruit others like themselves, while the opposite was true in the second arm of the study). RDS estimates of population proportions were also different between the two recruitment arms; in some cases corresponding confidence intervals between the two recruitment arms did not overlap. Further differences were revealed when comparisons of HIV prevalence were carried out. Conclusions: RDS is a cost-effective tool for data collection, however, seed selection has the potential to influence which subgroups within a population are accessed. Our findings indicate that using multiple methods for seed selection may improve access to hidden populations. Our results further highlight the need for a greater understanding of RDS to ensure appropriate, accurate and representative estimates of a population can be obtained from an RDS sample. © 2013 Wylie and Jolly; licensee BioMed Central Ltd.

Zubach V.,Public Health Agency of Canada | Smart G.,Cadham Provincial Laboratory | Ratnam S.,Public Health Agency of Canada | Ratnam S.,Memorial University of Newfoundland | And 2 more authors.
Journal of Clinical Microbiology | Year: 2012

We have developed a novel microsphere-based genotyping method for 46 mucosal human papillomavirus (HPV) types. HPV DNA was amplified by PCR using general primers and typed by hybridization to HPV type-specific probes coupled to sortable microspheres based on the Luminex xMAP technology. Hybridization to each probe was specific for each HPV type without cross-hybridization and sensitive enough to allow typing of HPV contained in clinical specimens. The method was validated with direct sequencing and the Roche Linear Array genotyping method. Copyright © 2012, American Society for Microbiology. All Rights Reserved.

Loeb M.,McMaster University | Russell M.L.,University of Calgary | Moss L.,McMaster University | Fonseca K.,University of Calgary | And 10 more authors.
JAMA - Journal of the American Medical Association | Year: 2010

Context: Children and adolescents appear to play an important role in the transmission of influenza. Selectively vaccinating youngsters against influenza may interrupt virus transmission and protect those not immunized. Objective: To assess whether vaccinating children and adolescents with inactivated influenza vaccine could prevent influenza in other community members. Design, Setting, and Participants: A cluster randomized trial involving 947 Canadian children and adolescents aged 36 months to 15 years who received study vaccine and 2326 community members who did not receive the study vaccine in 49 Hutterite colonies in Alberta, Saskatchewan, and Manitoba. Follow-up began December 28, 2008, and ended June 23, 2009. Intervention: Children were randomly assigned according to community and in a blinded manner to receive standard dosing of either inactivated trivalent influenza vaccine or hepatitis A vaccine, which was used as a control. Main Outcome Measures: Confirmed influenza A and B infection using a realtime reverse transcriptase polymerase chain reaction (RT-PCR) assay and by measuring serum hemagglutination inhibition titers. Results: The mean rate of study vaccine coverage among eligible participants was 83% (range, 53%-100%) for the influenza vaccine colonies and 79% (range, 50%-100%) for the hepatitis A vaccine colonies. Among nonrecipients, 39 of 1271 (3.1%) in the influenza vaccine colonies and 80 of 1055 (7.6%) in the hepatitis A vaccine colonies had influenza illness confirmed by RT-PCR, for a protective effectiveness of 61% (95% confidence interval [CI], 8%-83%; P=.03). Among all study participants (those who were and those who were not vaccinated), 80 of 1773 (4.5%) in the influenza vaccine colonies and 159 of 1500 (10.6%) in the hepatitis A vaccine colonies had influenza illness confirmed by RT-PCR for an overall protective effectiveness of 59% (95% CI, 5%-82%; P=.04). No serious vaccine adverse events were observed. Conclusion: Immunizing children and adolescents with inactivated influenza vaccine significantly protected unimmunized residents of rural communities against influenza. Trial Registration: Identifier: NCT00877396. ©2010 American Medical Association. All rights reserved.

Wylie J.L.,Cadham Provincial Laboratory | Van Caeseele P.,Cadham Provincial Laboratory
Sexually Transmitted Infections | Year: 2016

Objectives Increases in case numbers for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) have been noted on a global level. This study analysed 13 years of testing data to better understand case detection trends over time. Methods Data consisted of all nucleic acid probe and nucleic acid amplification diagnostic testing for CT and NG for the population of Manitoba, Canada (1.2 million); January 2000 to December 2012. Logistic regression models were used to analyse ORs associated with positive CT and NG tests by year. Included in the model as predictor variables were test type, specimen type, patient age and residence location. Results For both male and female CT results, unadjusted OR by year mimicked absolute case counts, reflecting a general increase over time in case counts. Adjustment for laboratory-related variables altered this relationship such that a general decline in the odds of identifying a CT case over time was evident. For both male and female NG results, adjustment for laboratory and demographic variables altered the OR associated with each year, but to a lesser extent than for CT. Conclusions Temporal trends associated with CT case numbers should be interpreted after controlling, at a minimum, for the influence of laboratory-related variables. Interpretation of NG trends is feasible using only the number of reported NG cases.

Kadkhoda K.,Cadham Provincial Laboratory | Kadkhoda K.,University of Manitoba | Smart G.,Cadham Provincial Laboratory
Clinical Laboratory | Year: 2014

Background: In North America, diagnosis of active hepatitis C virus (HCV) infection is currently performed using RNA testing which is highly sensitive and specific but is associated with three major limitations: lability of RNA molecules, higher costs, and longer turn-around time as compared with commercially-available HCV core antigen testing. In the current study, a new HCV core antigen assay product was evaluated for the diagnosis of HCV infection and its cost reducing potential. Methods: Ninety plasma specimens positive for HCV RNA along with 25 negative HCV specimens were used for HCV antigen assay. Twenty-four specimens positive for a panel of agents were used for possible cross-reactivity. Sixty-four HCV antibody-positive specimens with negative HCV RNA and indeterminate HCV immunoblot results were also employed. Results: In the first group, 78/90 (86.6%) tested positive for HCV antigen with regression analysis showing no significant deviation from linearity. None of the prenatal specimens tested positive for HCV antigen. Non-specific reactions were not observed. In the HCV antibody-indeterminate group, only 2/64 (3.1%) were antigen positive. In the last group, none of the HCV antibody very-low-positive specimens tested positive for HCV antigen. Both interand intra-run reproducibility of 100% were noted. The cost analysis showed a minimum of 52.13% reduction in costs associated with qualitative RNA testing. Conclusions: Considering the complexity of HCV infection diagnosis and the significant cost and turn-around time burden it imposes on clinical laboratories, HCV antigen testing seems an attractive adjunct to the current battery of laboratory diagnosis that demands more attention.

Alharbi S.,University of Umm Al - Qura | Van Caeseele P.,University of Manitoba | Van Caeseele P.,Cadham Provincial Laboratory | Consunji-Araneta R.,University of Manitoba | And 4 more authors.
BMC Infectious Diseases | Year: 2012

Background: Most pediatric adenovirus respiratory infections are mild and indistinguishable from other viral causes. However, in a few children, the disease can be severe and result in substantial morbidity. We describe the epidemiologic, clinical, radiologic features and outcome of adenovirus lower respiratory tract infections (LRTI) in Aboriginal and Non-Aboriginal children in Manitoba, Canada during the years 1991 and 2005.Methods: This was a retrospective study of 193 children who presented to the department of pediatrics at Winnipeg Children's Hospital, Manitoba, Canada with LRTI and had a positive respiratory culture for adenovirus. Patients' demographics, clinical and radiologic features and outcomes were collected. Adenovirus serotype distributions and temporal associations were described. Approximate incidence comparisons (detection rates) of adenovirus LRTI among Aboriginal and Non-Aboriginal children were estimated with 95% confidence intervals.Results: Adenovirus infections occurred throughout the year with clusters in the fall and winter. Serotypes 1 to 3 were the predominant isolates (two thirds of the cases). The infection was more frequent among Canadian Aboriginals, as illustrated in 2004, where its incidence in children 0-4 years old was 5.6 fold higher in Aboriginals (13.51 vs. 2.39 per 10,000, p < 0.000). There were no significant differences in length of hospitalization and use of ventilator assistance between the two groups (p > 0.185 and p > 0.624, respectively) nor across serotypes (p > 0.10 and p > 0.05, respectively). The disease primarily affected infants (median age, 9.5 months). Most children presented with bronchiolitis or pneumonia, with multi-lobar consolidations on the chest x-ray. Chronic (residual) changes were documented in 16 patients, with eight patients showing bronchiectasis on the chest computerized tomography scan.Conclusions: Adenovirus infection is associated with significant respiratory morbidities, especially in young infants. The infection appears to be more frequent in Aboriginal children. These results justify a careful follow-up for children with adenovirus LRTI. © 2012 Alharbi et al; licensee BioMed Central Ltd.

Wylie J.L.,Cadham Provincial Laboratory
Sexually transmitted infections | Year: 2010

Diez Roux has used the concept of complex systems to describe approaches for the incorporation of social factors into health research. These systems consist of heterogeneous interdependent units that also exhibit emergent properties. The latter embodies the concept that the interdependent units interact with and affect each other such that the resulting properties are not simple aggregates of the individual-level properties. This paper reviews research from Manitoba with a view towards conceptualising and phrasing the observed patterns within a complex system framework. A review of the temporal and spatial patterns seen within two large sexual network databases from Manitoba was undertaken and framed against the overlying patterns of sexually transmitted infection (STI) transmission within Manitoba. The review includes a summation of STI epidemiological patterns in Manitoba over a 5-year time frame, a comparison of temporal sexual network patterns, and an analysis of network patterns in relation to disparity in STI rates. Hypotheses are generated that focus on how individual-level behaviours and interactions create the observed complex system (network) patterns.

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