Bloodstream infections in adults: Importance of healthcare-associated infections

Summary Objective The objective of this study was to evaluate the characteristics of bloodstream infections occurring among outpatients having recent contact with the health care system compared to hospital and community-acquired infections. Methods Prospective observational cohort study of adult patients with bloodstream infections at three teaching hospitals. Bloodstream infection was defined as hospital-acquired if the first positive blood culture was performed more than 48 h after admission. Other bloodstream infections were classified as healthcare-associated or community-acquired. Results A total of 1157 episodes of bloodstream infections were studied; 581 (50.2%) were community-acquired, 295 (25.5%) were hospital-acquired, and 281 (24.3%) were health care-associated. Of the 281 health care-associated bloodstream infections, 68 (24%) occurred in patients residing in a nursing home, 104 (37%) in patients receiving intravenous therapy, health care at home, chemotherapy or attending dialysis, and 169 (60%) in patients hospitalized during the 90 days before their bloodstream infection (some patients belonged to more than one risk category). The highest prevalence rate of MRSA infections occurred in healthcare-associated infections (5%) ( p < 0.001). A significantly higher mortality rate was seen in the group with healthcare-associated infections (27.5%) than in community-acquired infections (10.4%) ( p < 0.001). Conclusions Our results confirm that healthcare-associated bloodstream infections show important differences from community-acquired bloodstream infections and suggest that empirical antibiotic therapy should be similar to hospital-acquired bloodstream infections, taking into account the epidemiologic characteristics of each region.