Prospective multicentric study of the etiology of 1051 bacteremic episodes in 782 cancer patients. CEMIC (French-Belgian Study Club of Infectious Diseases in Cancer)

Abstract

A total of 1051 bacteremic episodes (782 patients) were prospectively recorded in 10 cancer centers (9 French, 1 Belgian), with: patient's age (mean 53, range 1-89 years), underlying cancer, neutropenia (< 1000 neutrophils/microliters; 233), signs and symptoms, type of i.v. line (percutaneous central: 534; peripheral: 228; central implanted: 304), treatment, blood culture system, number of positive blood culture bottles/total obtained, time to growth. Of all episodes, 23.2% occurred within 48 h of admission. The patients were receiving systemic antibiotics at sampling (on AB) in 34.6% of cases. The 1147 pathogens isolated (86 polymicrobial) were: E. coli (10.7%), Klebsiella-Enterobacter-Serratia (6.1%), other enterobacteriaceae (2.2%), Pseudomonas aeruginosa (4.8%), other nonfermenters (4.7%), coagulase-negative staphylococci (CNS, 40.8%), Staphylococcus aureus (9.9%), streptococci (5.4%), enterococci (2.2%), anaerobes (3.4%), yeasts (3.5%), and other bacteria (6.9%). The CDC (Centers for Disease Control) criteria (1988) were used to assess significance: group 1: pathogenic species (616 episodes; 59%); group 2: clinical signs and isolation of a "contaminant" species (47; 4.5%); group 3: as in group 2 with an i.v. line and empiric antibiotic treatment (181 episodes including 176 CNS; 17%); group 4: non-significant (207 episodes including 203 CNS; 20%). Groups 1-3, in which the episodes were considered to be significant (844 episodes; 80%) were compared with non-significant episodes (Fisher). Significant differences (P < or = 0.05) were seen in time to growth (median growth within 24 h vs 48 h), fever (86% vs 54%), chills (40% vs 3%), hypotension (10% vs 2%), septic shock (9% vs 1%), polymicrobial etiology (10% vs 0.5%), and initiation of empiric antibiotic treatment (71% vs 4%). Bacteremic episodes of CDC groups 1, 3 and 4 were further studied in episodes with a single isolate as a doubtful clinical significance (482 episodes) and episodes with > or = 2 bottles positive of probable clinical significance (569 episodes; 54%). In group 1 (218 doubtful, 398 probably significant episodes) significant differences were seen in chills (36% vs 52%), shock (7% vs 13%), polymicrobial (8% vs 17%), initiation of empiric antibiotic treatment (60% vs 72%); in group 3 (87 doubtful, 94 probably significant) in time to growth delay; in group 4 (177 doubtful, 30 probably significant) in proportion with implanted catheter (26% vs 52%), fever (62% vs 10%), and time to growth. This study confirms the predominant role of Gram-positive cocci in bacteremia occurring in cancer patients.