Invasive CA-MRSA in northwestern Ontario: a 2-year prospective study.

Introduction: Northwestern Ontario has a documented high rate of skin and soft-tissue infections due to community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA). Recently, invasive illness from this common pathogen has become a serious clinical problem in the region. We sought to better understand this trend of invasive CA-MRSA.

Methods: We prospectively studied cases of positive CA-MRSA bacteremia in 2012 and 2013. We examined genetic typing, comorbidities and outcomes.

Results: Twenty-three cases of CA-MRSA bacteremia were treated during the 2-year study period. Intravenous drug use accounted for only 17% of cases. One death and 2 cases of endocarditis occurred.

Conclusion: High rates of CA-MRSA in skin and soft-tissue infections, combined with poor living conditions and poor access to potable water, may account for most of these cases of CA-MRSA bacteremia. Social determinants of health are relevant when common resistant bacterial isolates become associated with life-threatening illness.