Incidence of invasive aspergillosis following remission-induction chemotherapy for acute leukemia: a retrospective cohort study in a single Canadian tertiary care centre.

Abstract

The decision to use universal primary antimould prophylaxis to prevent invasive aspergillosis in patients with acute leukemia depends on the incidence of infection at individual centres. We determined our institution's incidence of invasive aspergillosis among patients who received remission-induction chemotherapy for acute leukemia to evaluate the potential benefits of primary antimould prophylaxis. We conducted this retrospective cohort study at a Canadian tertiary care centre. From the central pharmacy registries, we retrieved records for all adult patients for whom remission-induction chemotherapy for acute leukemia was prescribed between 2008 and 2010. We retrieved clinical, microbiologic, pathologic and radiologic data from the patients' medical charts. The primary outcome was a diagnosis of probable or proven invasive aspergillosis up to 180 days after resolution of aplasia. We retrieved records for 123patients with acute leukemia. Twenty-two of these patients did not receive the prescribed chemotherapy and were excluded from the analysis. Of the 101patients included, 77 (76.2%) had acute myeloid leukemia. Overall, 136courses of chemotherapy were administered, with more than 1 course administered to 26 (25.7%) of the 101patients. In 9 of the patients (8.9%; 95%confidence interval 4.2%-16.2%), invasive aspergillosis was diagnosed (3proven and 6probable cases) a median of 19 (range 11-34) days after initiation of chemotherapy. In 7 (78%) of these 9patients, invasive aspergillosis occurred during the first course of chemotherapy. Three patients died within the first year after diagnosis of invasive aspergillosis. We found a high incidence (8.9%) of invasive aspergillosis at our centre. This finding triggered the introduction of targeted antimould prophylaxis for patients with acute leukemia who were undergoing remission-induction chemotherapy.