Bloodstream infections in cancer patients with febrile neutropenia.

Bloodstream infections (bacteraemia) account for approximately 25-30% of febrile episodes in patients with febrile neutropenia (FN). In developed countries, Gram-positive pathogens predominate. Mortality is higher in Gram-negative bacteraemia. A recent study involving 2142 patients with FN was reviewed, including 168 patients with Gram-negative bacteraemia (mortality 18%), 283 patients with Gram-positive bacteraemia (mortality 5%) and 48 patients with polymicrobial bacteraemia (mortality 13%). Among patients who received prophylactic antibiotics, Gram-positive bacteraemia was far more common than Gram-negative bacteraemia (75% vs. 25%), compared with approximately 50% of each in patients without prophylactic antibiotics. Patients with a Multinational Association for Supportive Care in Cancer (MASCC) score <15 had a 36% mortality compared with 3% if the MASCC score was >21. The MASCC score may help risk stratification of patients with FN and bacteraemia, although these data require confirmation. In two series of patients from developing countries (Lebanon and Malaysia), Gram-negative bacteraemia was more common and mortality was higher. In developing countries, Gram-negative bacteraemia may be more frequent due to less use of prophylactic antibiotics and central lines. Laboratory markers may have predictive and prognostic value for bacteraemia in patients at the onset of FN, including mannose-binding lectin, interleukin (IL)-6, IL-8 and procalcitonin, but further studies are required before they can be recommended. New therapies are required to lower the mortality in patients with FN with a high risk for bacteraemia.