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.

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. Group A Streptococcus (GAS) causes a wide variety of diseases ranging in severity from uncomplicated pharyngitis to lifethreatening necrotizing fasciitis and streptococcal toxic shock syndrome (1). More than 240 GAS emm types are recognized based on the sequence of the hypervariable 5= end of gene emm, encoding M protein, a major GAS virulence factor with antiphagocytic properties (2-4). Beginning in 2006, Canada experienced an epidemic of invasive GAS (iGAS) infections caused by strains of the previously rare emm59 type (5). A hypervirulent clone, which later disseminated to several areas of the United States, was shown to be responsible for hundreds of cases countrywide (6-10). Invasive type emm59 strains were frequently isolated from soft tissue infections and were recovered in higher percentages from patients with distinctive risk factors, including alcohol abuse, homelessness, hepatitis C virus (HCV) infection, and intravenous drug use (IVDU) (5, 6). In the province of Ontario, most emm59 iGAS infections occurred in Thunder Bay, the most populous municipality in the Northwestern area of the province (population, approximately 110,000), and the regional center of the Thunder Bay District (TBD), which extends over an area of 103,720 square kilometers.The number of emm59 iGAS cases in Canada, particularly in Ontario, has been in continuous decline since 2010 (8). However, TBD public health authorities continue to observe ra...