Clinical Manifestations and Outcomes of Hospitalized Patients with Blastomycosis: A provincial cohort study

Abstract Background Blastomycosis is a rare but potentially life-threatening infection caused by Blastomyces spp. that is endemic in the Canadian provinces of Manitoba and Northwestern Ontario. Given evolving epidemiology of endemic mycoses, we sought to evaluate the provincial experience managing inpatients with blastomycosis over time. The objectives were to describe the risk factors, predictors of poor outcomes among patients hospitalized with blastomycosis throughout Manitoba. Methods We performed a provincial retrospective cohort study by identifying all culture-positive clinical specimens yielding Blastomyces spp. within Manitoba, using the Provincial Lab Information System. We included all adult patients who required admission to hospital for infectious manifestations of microbiologically confirmed blastomycosis since 2006. We used a multivariate regression model to predict associations with mortality. Results Of 317 patients with culture positive Blastomyces spp., we included 141 hospitalized patients across 7 hospitals. Overall, in-hospital mortality was 24%. The presence of chest pain at presentation to hospital (odds ratio (OR) 3.24, 95% confidence interval (CI) 1.26-8.83) was associated with mortality. Hospital admissions, ICU admissions and mortality have a positive temporal trend over the study period. Conclusions Blastomycosis is associated with significant morbidity and mortality, both of which is increased over time. Further studies are needed to evaluate effective diagnostic and treatment strategies to improve outcomes.