Showing papers by "Saskatchewan Health published in 2005"

Community-associated Methicillin-resistant Staphylococcus aureus, Canada

Abstract: A total of 184 methicillin-resistant Staphylococcus aureus (MRSA) strains were collected from patients who sought treatment primarily for skin and soft tissue infections from January 1, 1999, to March 31, 2002, in east-central Saskatchewan, Canada. Molecular subtyping analysis using pulsed-field gel electrophoresis showed 2 major clusters. Cluster A (n = 55) was composed of a multidrug-resistant MRSA strain associated with a long-term care facility and was similar to the previously reported nosocomial Canadian epidemic strain labeled CMRSA-2. Cluster B (n = 125) was associated with cases identified at community health centers and was indistinguishable from a community-associated (CA)-MRSA strain identified previously in the United States (USA400). Cluster B remained susceptible to a number of classes of antimicrobial agents and harbored the lukF-PV and lukS-PV toxin genes. Over 50% of both clonal groups displayed high-level resistance to mupirocin. This is the first report of the USA400 strain harboring the lukF-PV and lukS-PV toxin genes in Canada.

Development of a Triplex Real-Time PCR Assay for Detection of Panton-Valentine Leukocidin Toxin Genes in Clinical Isolates of Methicillin-Resistant Staphylococcus aureus

Abstract: Community-associated methicillin-resistant Staphylococcus aureus harboring Panton-Valentine leukocidin (PVL) genes is an emerging pathogen. A novel real-time PCR assay for identification of MRSA isolates containing PVL was developed. The PVL assay was used in a triplex format allowing simultaneous amplification of mecA, nuc, and PVL genes in 614 clinical isolates. This assay facilitates the rapid identification of PVL-positive isolates of MRSA.

Use of Immunoglobulin G Avidity Assays for Differentiation of Primary from Previous Infections with West Nile Virus

Abstract: Since its introduction in 1999, West Nile virus (WNV) infections have spread rapidly across the North American continent. Diagnosis of acute WNV infection by detection of WNV-specific immunoglobulin M (IgM) is complicated by the persistence of detectable IgM for more than 1 year in some patients. IgG antibody avidity testing was assessed as a supplemental assay in the diagnosis of current infections. Three groups of serum samples were assayed in parallel by two different IgG avidity test systems (indirect immunofluorescence test [IIFT] and prototype enzyme-linked immunosorbent assay [ELISA]; EUROIMMUN, Luebeck, Germany). Group I (40 sera taken between 2 and 9 days after the onset of influenza-like symptoms) and group II (40 sera taken between 10 and 43 days after onset) were acute and convalescent specimens from patients with a positive anti-WNV IgM test (ELISA; Focus Diagnostics, Cypress, CA). Group III consisted of 43 patient sera collected between 6 and 12 months after infection. IgG antibodies specific for WNV were detected in 38% (ELISA) and 50% (IIFT) of group I sera, in 90% (ELISA and IIFT) of group II sera, and in 100% (ELISA and IIFT) of group III sera. Low-avidity IgG antibodies were demonstrated in 86% (ELISA) and 95% (IIFT) of IgG-positive patient samples taken between 2 and 43 days after the onset of symptoms (groups I and II). High-avidity IgG antibodies were detected in 100% of group III sera obtained 6 months or more after the onset of symptoms (ELISA and IIFT). IgG avidity tests for WNV infections are rapid and simple to perform. The determination of IgG avidity provides additional diagnostic certainty in differentiating between recently acquired and previous infections with WNV.

Rapid Genotyping of Hepatitis C Virus by Primer-Specific Extension Analysis

Abstract: Infection by hepatitis C virus (HCV) is the leading cause of chronic liver disease worldwide (19). The overall prevalence of HCV infection in the United States is 1.8%, with most of the patients unaware of their infection and at risk for developing cirrhosis and hepatocellular carcinoma (15, 21). HCV is a positive-sense, single-stranded RNA virus that displays extensive genetic heterogeneity (1). At least six major HCV genotypes comprising numerous, more closely related subtypes have been identified (26). HCV genotypes display significant differences in their global distribution and prevalence, making genotyping a useful method for determining the source of HCV transmission in an infected localized population (11). Furthermore, in addition to viral load and liver histology, the genotype of the infecting HCV strain appears to be an important determinant of the severity and aggressiveness of liver infection, as well as patient response to antiviral therapy (26). Consequently, several methods for genotyping HCV have been developed, including direct DNA sequencing (2, 5, 6), type-specific PCR (17), restriction fragment length polymorphism (16), line probe assays (22, 23), primer-specific and mispair extension analysis (7, 8), heteroduplex mobility analysis by temperature gradient capillary electrophoresis (14), and denaturing high-performance liquid chromatography (13). The majority of the HCV genotyping assays in use today were designed to identify only the dominant HCV genotype in a sample and consequently are unable or limited in their ability to identify multiple genotypes in patients infected with more than one strain of HCV. Hu et al. (7) have found that of the HCV infections determined to contain mixed genotypes by DNA sequencing, only 36%, 17%, and 14% were accurately identified as mixtures by type-specific PCR, line probe, and restriction fragment length polymorphism analyses, respectively. Furthermore, DNA sequencing itself was unable to detect 40% of the mixed-genotype infections and could not reliably detect genotypes that were present in mixtures at levels below 25% (7). Consequently, most currently available genotyping methods are unable to assess the prevalence of mixed-genotype infections, which may have a significant impact on the interpretation of clinical studies addressing genotype-specific responses to interferon and interferon combination therapies. As injection drug use is the major risk factor for HCV infection in Canada, accounting for 71% of the cases (3), the occurrence of mixed-genotype infections may be more common than previously reported, as this route of transmission may result in multiple exposures to different HCV strains in habitual users. Moreover, individuals infected with HCV via repeated blood transfusions are also potential carriers of multiple HCV genotypes. We have developed a novel genotyping method to identify the most prevalent genotypes among HCV-infected Canadians, which is based on primer-specific extension analysis (PSEA) of HCV PCR amplicons, called PSEA-HCV. That is, primers specific for genotypes 1, 2, 3, and 4 and subtypes 1a, 1b, 2a/c, and 2b were designed to bind to variable regions within the amplified 5′ untranslated region (UTR) of the HCV genome. The PSEA-HCV assay, utilizing the inefficiency of Taq DNA polymerase to extend a mismatch at the 3′ end of a primer, has demonstrated predicted products against known HCV genotypes. Another primer targeted for a conserved region among all genotypes was designed for use as an internal control (IC). We report here on the PSEA strategy and its performance against known HCV genotypes typed by INNO-LiPA HCV II (23). Simulated mixed infections were also assayed by PSEA-HCV, and this work demonstrates the ability of this novel method to identify multiple genotypes and in ratios of up to 31:1.

To what extent does poor health precede welfare

Abstract: It is well known that individuals receiving social assistance have more health problems than those with higher incomes. In this paper, we estimate the proportion of social assistance recipients who were on welfare following a drop in health status. The study population consisted of Saskatchewan adults who had been continuously off social assistance for 12 consecutive months followed by 6 months on social assistance. Health status was measured by the use of physician services. We examined changes in physician service rates during the 18-month period. Forty-nine percent of individuals in the study population had increases in the number of physician services over the 18-month period. For these individuals, 53% of the increase in service use occurred during the 12 months prior to receiving social assistance. Deteriorating health, as measured by increased physician service use, seems to be one factor that precedes many people’s receipt of welfare. A focus on improving health status may be one way to keep people off welfare.

Multilocus sequence typing of Escherichia coli O26:H11 isolates carrying stx in canada does not identify genetic diversity.

Abstract: Multilocus sequence typing of 31 stx-carrying Escherichia coli O26:H11 strains isolated in Canada between 1999 and 2003 revealed a high degree of genetic relatedness at 10 loci, suggesting either that this is a clonal serotype (similar to O157:H7) or that additional genetic loci need to be examined.

Extreme Makeover: Can We Achieve Rapid Improvement in Canada's Healthcare System?

Abstract: Building upon some key discussion points in the Brown et al. paper, we explore the key elements driving performance measurement and quality improvement strategies in the Veterans Affairs healthcare system in the United States and the national primary-care trusts in England, both of which offer important insights into understanding the factors that affect rapid, large-scale change. In the context of these "extreme makeover" examples, our commentary discusses the currently evolving performance measurement culture in the Canadian primary healthcare reform setting. We specifically highlight the experiences in Saskatchewan, a province that has been acknowledged recently by CIHI as a leader in primary healthcare evaluation. Although Saskatchewan has attempted to overcome the methodological and conceptual challenges in evaluation that Brown et al. outline in their paper, a stable performance measurement culture has yet to emerge and systematically utilize performance measurement reports for purposes of facilitating change. Although there is a growing recognition that measures by themselves will not be able to spur improvement, it is yet to be seen to what extent these performance reports can speak compellingly to policymakers, primary healthcare providers and managers to serve as catalysts to a major leap forward in overall quality improvement.