Rectal Colonization Study and its Impact on Blood Stream Infection in Hospitalized Pediatric Oncology Patients

Abstract Background Colonization with multidrug resistant organisms (MDRO) is associated with bacterial translocation, which can result in subsequent endogenous blood stream infection (BSI) with high morbidity and mortality. Surveillance rectal swabs can aid in the choice of empiric antimicrobial during episodes of neutropenic fever. Aim To compare types of organisms and prevalence of MDRO obtained from both surveillance rectal swabs and blood cultures among leukemia patients with BSI. Methodology we conducted a 6 month-cross-sectional observational study that included 45 patients with acute leukemia during hospital admission at the pediatric hematology/oncology inpatient ward, Ain Shams University, with review of any antimicrobial intake or hospital admission in the last 3 months before initial presentation. Surveillance rectal swab were done upon 1st admission before start of antimicrobials. Repeat surveillance swabs with any subsequent admission, complete blood counts (CBC) and blood culture were withdrawn with the 1st febrile episode, antimicrobial susceptibility were assessed by disc diffusion. Results The mean (±SD) age of the studied cohort was 6.84 (±3.16) years, 60.0% were B-ALL, 31.1% AML and 8.6% T-ALL. Nine patients (n = 20.0%) received antibiotic prior to admission. Seventeen patients (37.7%); including n = 3 (18.7%) with prior antibiotic intake; had initial positive rectal swab with 94.1% with gram negative resistant strains (GN R), 56.2% of them were extended spectrum beta lactamase (ESBL), 25% MDRO Carbapenem sensitive and 18.7% carbapenem resistant. With development of febrile episode, 48.8% developed bacteremia with 45.4% showed growth of GN R, among which 13.6% demonstrated same type of organism and pattern of resistance of surveillance swab. As for follow up surveillance swabs only 11.6% had positive swabs, with only 1 patient (5.8%) was persistently positive for the same GN R organism as the initial swab. Conclusion Rectal colonization are present in high frequency in children with cancer at diagnosis, many of them were gram negative resistant strains. The same types of organism in rectal swab and BSI are encountered in the majority of neutropenic patients, which needs to be identified for proper empiric antimicrobial selection during febrile episodes.