Population-based risk factors for community-onset bloodstream infections.

Although a number of comorbidities have been associated with development of bloodstream infection, actual risk factors have not been well defined and quantified in nonselected populations. We sought to quantify population-based risk factors for development of community-onset bloodstream infection (COBSI). Surveillance was conducted among all residents of the Western Interior of British Columbia, Canada, during 2011-2018. Risks were expressed as incidence rate ratios (IRR) with 95% confidence intervals (CI). The annual incidence was 147.1 per 100,000 and older individuals, and males were at overall higher risk. The median Charlson score was 2 (IQR, 0-3), and this was higher among those with healthcare-associated (2; IQR, 1-4) as compared to community-associated (1; IQR, 0-2; P < 0.0001) COBSI. Risk factors for development of COBSI included (IRR; 95% CI): HIV infection (8.89; 5.17-14.27), cancer (6.80; 6.13-7.54), congestive heart failure (4.68; 4.00-5.46), dementia (3.31; 2.82-3.87), diabetes mellitus (3.10; 2.80-3.42), cerebrovascular accident (2.79; 2.34-3.31), renal dysfunction (2.75; 2.33-3.22), chronic lung disease (2.03; 1.79-2.28), peripheral vascular disease (1.68; 1.39-2.01), and rheumatic disease (1.44; 1.14-1.79). Patients with multiple comorbid illnesses were older, more likely to be male, and have healthcare-associated BSI, higher rates of antimicrobial resistance, and different clinical foci of infection. A number of demographic and comorbid conditions significantly increase the risk for development of COBSI.