High Incidence of Invasive Group A Streptococcus Disease Caused by Strains of Uncommon emm Types in Thunder Bay, Ontario, Canada.

An outbreak of type emm59 invasive group A Streptococcus (iGAS) disease was declared in 2008 in Thunder Bay District, Northwestern Ontario, 2 years after a countrywide emm59 epidemic was recognized in Canada. Despite a declining number of emm59 infections since 2010, numerous cases of iGAS disease continue to be reported in the area. We collected clinical information on all iGAS cases recorded in Thunder Bay District from 2008 to 2013. We also emm typed and sequenced the genomes of all available strains isolated from 2011 to 2013 from iGAS infections and from severe cases of soft tissue infections. We used whole-genome sequencing data to investigate the population structure of GAS strains of the most frequently isolated emm types. We report an increased incidence of iGAS in Thunder Bay compared to the metropolitan area of Toronto/Peel and the province of Ontario. Illicit drug use, alcohol abuse, homelessness, and hepatitis C infection were underlying diseases or conditions that might have predisposed patients to iGAS disease. Most cases were caused by clonal strains of skin or generalist emm types (i.e., emm82, emm87, emm101, emm4, emm83, and emm114) uncommonly seen in other areas of the province. We observed rapid waxing and waning of emm types causing disease and their replacement by other emm types associated with the same tissue tropisms. Thus, iGAS disease in Thunder Bay District predominantly affects a select population of disadvantaged persons and is caused by clonally related strains of a few skin and generalist emm types less commonly associated with iGAS in other areas of Ontario.

Prevalence and factors affecting breastfeeding among Aboriginal women in Northwestern Ontario.

OBJECTIVE: To evaluate breastfeeding outcomes among Aboriginal women and to determine variables affecting breastfeeding in the early postpartum period. DESIGN: Prospective cohort study. SETTING: Two sites in Northwestern Ontario, Canada: a tertiary care center and a rural hospital. PARTICIPANTS: One hundred thirty breastfeeding Aboriginal women agreed to participate in the study. METHODS: All women completed a baseline survey in hospital that included questions regarding demographic, prenatal, breastfeeding, obstetric, postpartum, and neonatal characteristics. Women were then telephoned at 4 and 8 weeks postpartum to complete additional questionnaires regarding infant feeding. RESULTS: Low rates of breastfeeding initiation (69%) and exclusive breastfeeding were identified at 4 (37.5%) and 8 (35.3%) weeks postpartum. Among those who initiated breastfeeding, duration rates at 4 (86%) and 8 weeks (78%) postpartum are comparable to other studies. Variables associated with any and exclusive breastfeeding at 8 weeks included the following: (a) household income, (b) intended breastfeeding duration, (c) plan to exclusively breastfeed, (d) perception of meeting their planned duration goal, and (e) higher breastfeeding self-efficacy. Partner support was associated with any breastfeeding at 8 weeks but not exclusivity. Women who were breastfeeding exclusively in hospital (prevalence ratio [PR] = .48, 95% confidence interval [CI] [0.27, 0.86]), did not smoke (PR = 2.5, 95% CI [1.4, 4.3]) and/or use substances during pregnancy (PR = 4.5, 95% CI [1.5, 14]) were more likely to be breastfeeding exclusively at 8 weeks. CONCLUSION: Many of the variables may be considered modifiable and amenable to intervention. Targeted interventions should be directed toward improving breastfeeding outcomes among Aboriginal women.

Epidemic of group A Streptococcus M/emm59 causing invasive disease in Canada.

BACKGROUND: The incidence of invasive group A Streptococcus (GAS) disease can vary over time and geographic region, possibly reflecting the population's susceptibility to particular strains but also variation in the predominant M/emm types. Canadian surveillance documented an epidemic of an uncommon M/emm59 type from 2006 to 2009. METHODS: Invasive GAS isolates are submitted by Public Health Laboratories in Canada to the National Centre for Streptococcus for M/emm typing. Patient age, sex, geographic location, and the anatomical source of isolate are provided with the isolate. When it was recognized that M/emm59 strains were increasing in prevalence, clinical information was collected on M/emm59 cases captured in Alberta and compared with cases of other M/emm types occurring in this province. RESULTS: From January 2006 through December 2009, 539 (13.0%) of 4150 invasive GAS cases were identified as M/emm59: 164 from British Columbia, 146 from Alberta, 62 from Saskatchewan, 82 from Manitoba, 68 from Ontario, 14 from Quebec, 1 from New Brunswick, 1 from Newfoundland, 1 from Yukon, and 1 from Nunavut. The predominant clinical presentation was bacteremia (45.0%) followed by cellulitis (41.4%). Compared with concurrent cases of invasive GAS disease caused by all other M/emm types, identified risk factors for M/emm59 disease were alcohol abuse (odds ratio [OR], 2.3; 95% confidence interval [CI], 1.4-3.8), homelessness (OR, 2.0; 95% CI, 1.2-3.4), hepatitis C virus infection (OR, 2.0; 95% CI, 1.1-3.5), and illicit drug use (OR, 1.7; 95% CI, 1.0-3.0). CONCLUSIONS: Western Canada has witnessed the rapid emergence of a rare GAS strain causing invasive disease predominately in a select population of disadvantaged persons.

Cancer risk associated with pulp and paper mills: a review of occupational and community epidemiology.

Pulp and paper mills use a variety of chemical substances potentially hazardous to human health. Compounds of both short- and long-term toxicological significance are found in workplaces, air emissions, and water effluent. In this paper we evaluate the body of published literature on cancer associated with working in pulp and paper mills as well as in surrounding communities. Multiple comparisons, questionable statistical power, and the absence of individual exposure assessments have resulted in non-corroborative findings over the years. However, a new generation of study sophistication, international in scale and coordinated by the International Agency for Research on Cancer (IARC), has catalogued tens of thousands of exposure measurements made at a large number of work stations within the pulp and paper industry, allowing for greatly improved individual-level exposure assessments. This approach reduces non-differential misclassification of exposure, increasing the power of these studies to detect exposure disease relationships, especially for rarer cancers. While the ability to associate specific chemical exposures with cancer outcomes in the large IARC multinational cohort may yet help to resolve the status of some of the many chemicals not currently classifiable as to their carcinogenicity by IARC, this effort has, to date, not added significantly to knowledge. Of the three studies they have published to date, one involved a well-established carcinogen (asbestos) and another involved a mixture containing probable carcinogens (volatile organochlorines). While the asbestos study is somewhat unremarkable for finding an association with pleural cancer in the expected direction, the volatile organochlorine study may be most notable for failing to find an association between volatile organochlorine exposure and liver cancer, non-Hodgkin's lymphoma, or esophageal cancer, as some previous studies had found. Nonetheless, given the known hazards and the potential for both environmental and human exposure by any of a number of pathways, vigilance on the part of governments for regulation and for ongoing workplace and environmental monitoring remains a health imperative.

Omega-3 fatty acids as treatments for mental illness: which disorder and which fatty acid?

BACKGROUND: A growing number of observational and epidemiological studies have suggested that mental illness, in particular mood disorders, is associated with reduced dietary intake and/or cellular abundance of omega-3 polyunsaturated fatty acids (PUFA). This has prompted researchers to test the efficacy of omega-3 PUFA in a range of different psychiatric disorders. We have critically reviewed the double blind placebo controlled clinical trials published prior to April 2007 to determine whether omega-3 PUFA are likely to be efficacious in these disorders. RESULTS: Most trials involved a small number of participants but were largely well designed. Omega-3 PUFA were well tolerated by both children and adults with mild gastrointestinal effects being the only consistently reported adverse event. For schizophrenia and borderline personality disorder we found little evidence of a robust clinically relevant effect. In the case of attention deficit hyperactivity disorder and related disorders, most trials showed at most small benefits over placebo. A limited meta-analysis of these trials suggested that benefits of omega-3 PUFA supplementation may be greater in a classroom setting than at home. Some evidence indicates that omega-3 PUFA may reduce symptoms of anxiety although the data is preliminary and inconclusive. The most convincing evidence for beneficial effects of omega-3 PUFA is to be found in mood disorders. A meta-analysis of trials involving patients with major depressive disorder and bipolar disorder provided evidence that omega-3 PUFA supplementation reduces symptoms of depression. Furthermore, meta-regression analysis suggests that supplementation with eicosapentaenoic acid may be more beneficial in mood disorders than with docosahexaenoic acid, although several confounding factors prevented a definitive conclusion being made regarding which species of omega-3 PUFA is most beneficial. The mechanisms underlying the apparent efficacy of omega-3 PUFA in mood disorders compared to schizophrenia are discussed as is a rational for the possibly greater efficacy of EPA compared to DHA. CONCLUSION: While it is not currently possible to recommend omega-3 PUFA as either a mono- or adjunctive-therapy in any mental illness, the available evidence is strong enough to justify continued study, especially with regard to attentional, anxiety and mood disorders.

Relationship between Crohn's disease, infection with Mycobacterium avium subspecies paratuberculosis and SLC11A1 gene polymorphisms in Sardinian patients.

AIM: To study the association between Crohn's disease (CD), Mycobacterium avium subspecies paratuberculosis (MAP), and genetic factors by examining the role of natural resistance-associated macrophage protein 1 (NRAMP1) gene polymorphisms (now SLC11A1) in Sardinian patients with CD and controls. METHODS: Thirty-seven CD patients and 34 controls with no inflammatory bowel disease (IBD) were recruited at the University of Sassari after giving written consent. Six SCL11A1 polymorphisms previously reported to be the most significantly associated with IBD were searched. M. paratuberculosis was identified by IS900 PCR and sequencing. Logistic regression was used to calculate odds ratios (OR) for the associations among CD, presence of MAP, and 6 loci described above. RESULTS: For the first time, a strong association was observed between polymorphisms at NRAMP1 locus 823C/T and CD. While CD was strongly associated with both NRAMP1 and MAP, NRAMP1 polymorphisms and MAP themselves were not correlated. CONCLUSION: Combined with previous work on the NOD2/CARD15 gene, it is clear that the interplay of genetic, infectious, and immunologic factors in the etiology of CD is complex.

Implementing ethics in the professions: examples from environmental epidemiology.

The need to integrate ethics into professional life, from the grassroots up, has been recognized, and a comprehensive ethics program has been proposed as a model. The model includes the four dimensions of: consensus building, ethics guidelines development and review, education, and implementation. The activities of the International Society for Environmental Epidemiology (ISEE) are presented as examples and compared with the proposed model. Several innovative activities are described and incentives for ethical professional conduct are highlighted. The examples are provided for emulation by other professional organizations in the hope that, thereby, greater protection of the public interest will be achieved.