Survey of blood cultures from five community hospitals in south-western Sydney, Australia, 1993-1994

Background: Blood culture results have profound implications for patients. Comprehensive overviews of blood cultures have been uncommon, and focused on tertiary referral hospitals. Aim: To present a review of blood culture results from a laboratory servicing community hospitals in Sydney, Australia. Methods: Retrospective chart review of patients with positive blood cultures from 1 June 1993 to 31 May 1994. Results: During the survey period there were 107,382 hospital admissions; 12,109 blood culture sets from 9292 patients were processed. Of these 1197 sets were positive, representing 974 febrile episodes in 923 patients. There were 476 episodes of contamination. Of the episodes of true bacteraemia, Escherichia coli was isolated in 139, Staphylococcus aureus in 91 (22 methicillin-resistant), other enterobacteriaceae in 60, and Streptococcus pneumoniae in 51. The diagnoses attributable to bacteraemia included intravenous catheter-related sepsis (122 episodes), urinary tract infection (88), bacteraemia from unknown source (79), intra-abdominal and biliary sepsis (91), pneumonia (35), and meningitis (21). Sixty-eight patients died directly due to bacteraemia. Multivariate analysis showed underlying disease (OR 3.97) or shock (OR 28.1) predicted death. Blood cultures confirmed clinical diagnoses in 258 episodes, but made a de novo diagnosis in 205 episodes. Conclusions: This study describes the clinical and laboratory features of bacteraemias occurring in smaller public hospitals, as distinct from tertiary referral centres. It demonstrated that intravenous catheter-related sepsis was very common in smaller hospitals. The clinical diagnosis was frequently confirmed, and a de novo diagnosis was often established by a positive blood culture. Unfortunately nearly half the positive blood cultures represented contamination.