Potentially pathogenic microorganisms in the oral cavity during febrile episodes in immunocompromised patients with haematologic malignancies.

The purpose of the study was to describe the occurrence of potentially pathogenic microorganisms during febrile episodes in haematologic patients, who had been treated with anti-neoplastic drugs within the previous 4 weeks. During a 9-month period 78 consecutive febrile episodes occurred in 46 patients who were examined daily. On day 1, before antibiotic treatment was started, members of the normal flora were found in 83%, Candida spp. in 72%, Enterobacteriaceae in 29%, Pseudomonas aeruginosa in 8%, Staphylococcus aureus in 14%, coagulase-negative staphylococci in 26% and enterococci in 17% of the febrile episodes. During the subsequent antibiotic treatment, the prevalence of members of the normal oral flora was markedly reduced from day 1 (83%) to day 7 (6%), and the normal flora was replaced by potentially pathogenic microorganisms. A rise was found in the prevalences of Candida spp. (from 72 to 92%) and coagulase-negative staphylococci (from 26 to 49%) from day 1 to day 4. The prevalences of Enterobacteriaceae and P. aeruginosa showed no day-to-day changes, and were not different in patients hospitalized for more or less than 24 h prior to inclusion into the study, suggesting that their detection was not due to acquisition during hospitalization or antibiotic treatment. The oral occurrence of species of microorganisms regularly found in septicaemia, suggests that the oral cavity may play a role as a port of entry of septicaemia in patients with haematologic malignancies.