PS1281 EFFICACY OF ACTIVE SURVEILLANCE IN REDUCING MORTALITY DUE TO MULTIDRUG RESISTANT BACTERIA IN ACUTE LEUKEMIA

Background: We have observed a high incidence of BLEE and carbapenemase Gram negative strains in our center (18 and 40% respectively), leading to high morbidity and mortality in acute myeloid leukemia patients (AML). The effect of routine screening for gastrointestinal colonization in AML patients is unclear. However, potential benefits include limiting the spread of Gram negative multiresistant bacteria (GNMRB) and guiding the empirical therapy for febrile episodes. Aims: To analyze the effect of routine surveillance cultures (RSC) along with intensified infection control measures (active surveillance program, ASP) in the prevention of GNMRB infectious episodes and mortality of AML patients receiving intensive chemotherapy. Methods: This was a prospective observational study including all consecutive adult patients with an AML diagnosis, treated with intensive chemotherapy at Hospital Universitario Central de Asturias (HUCA) from January 2015 to January 2019. The cohort of patients in whom RSC were performed (cohort 2) was compared to a cohort of AML patients in whom RS was not done (cohort 1). All patients received fluoroquinolone prophylaxis. Data are presented as mean ± standard deviation or as median (range). Univariate comparisons were done using the chi‐square test (categorical variables) or Fisheŕs exact test (for contingency tables with frequencies below 5). Results: 103 patients were included, 36 in cohort 1 and 67 in cohort 2. Median age of the whole population was 57 years (47–64), being female 46%. According to European Leukemia Net (ELN 2016) criteria, 43 patients (42%) belong to the low risk category, 27 (26%) to the intermediate and 33 (32%) to higher risk. There were no significant differences in demographic and prognostic characteristics between cohorts. A total of 230 chemotherapy cycles were administered. Thirty‐one patients received and allogeneic stem cell transplant (SCT). The proportion of colonized patients with a GNMRB in each cycle was as follow: induction‐1: 34% (23 of 44 patients) induction‐2: 67% (8 of 12), consolidation 1: 58% (22 of 38), consolidation 2: 31% (5 of 11), consolidation 3: 45% (5 of 11). The proportion of febrile episodes caused by GNMRB in each cycle and cohort (c) was induction‐1 (18% c‐1, 27% c‐2; P = 0.58) induction‐2 (0% c‐1, 36% c‐2; P = 0.2), consolidation 1 (38% c‐1, 35% c‐2 P = 1), consolidation 2 (9% c‐1, 11% c‐2; P = 0.8), consolidation 3 (0 c‐1, 27% c‐2 P = 1). A significant reduction in GNMRB infections was observed during the second year after the initiation of the ASP (30 vs 10% of, P = 0.04). When patients were censored at SCT, the infection free survival was significantly better in cohort 2, Log Rank P < 0.0001, being infection the main cause of dead in cohort 1, as opposed to cohort 2 in which the leading cause of death was relapse or progression, P = 0.059. Summary/Conclusion: Routine surveillance cultures and intensified infection control measures are effective in preventing both transmission and reducing mortality related to GNMR in AML patients.