Bacteraemia post-autologous haematopoietic stem cell transplantation in the absence of antibacterial prophylaxis: a decade's experience from Lebanon.

PURPOSE: In this study, we assessed the incidence, contributing factors and outcome of prolonged neutropenia above 7 days and of bacteraemia in patients with lymphoma and multiple myeloma who underwent autologous haematopoietic stem cell transplantation (AHSCT) without antibacterial prophylaxis. METHODS: This is a retrospective chart review of 190 adult patients who underwent AHSCT between 2005 and 2015 at a Lebanese hospital. RESULTS: Neutropenia of 7 days duration and longer was documented in 66% of the patient population. Through univariate analysis, patients with lymphoma were significantly more likely to have prolonged neutropenia (≥ 7 days) compared to those with myeloma. Mucositis above grade 3, diarrhoea and fever were more likely to occur in patients with prolonged neutropenia. Bacteraemia was documented in 12.6% of the patients. Total mortality rate was 3.7%, and that attributed to bacteraemia was 12.5% in the bacteraemia subgroup. Among bacterial isolates recovered from clinical specimens (89 isolates), 70% were Gram-negative, of which 57% were fluoroquinolone susceptible. Ninety-five percent of the Gram-negative bacteria causing bacteraemia were susceptible to fluoroquinolones. CONCLUSION: Bacterial pathogens causing bacteraemia were still highly susceptible to fluoroquinolones, despite the high prevalence of fluoroquinolone-resistant strains in the general bacterial ecology. Accordingly, the pertinence of fluoroquinolone prophylaxis in the AHSCT setting warrants further investigation. Moreover, continuous surveillance of local antibiograms in this patient population has become a must in an era of preponderant antibiotic resistance.

Epidemiology of bacteremia after autologous hematopoietic stem cell transplantation in the absence of antibiotic prophylaxis.

INTRODUCTION: Bacterial infections are frequent complications occurring after autologous hematopoietic stem-cell transplantation (AHSCT). Herein, we identified the bacterial ecology and its antibiogram in AHSCT patients. We assessed the incidence, contributing factors and outcome of prolonged neutropenia and bacteremia post-AHSCT in the absence of antibacterial prophylaxis. METHODOLOGY: This is a retrospective chart review of 190 adult patients who underwent AHSCT for lymphoma and multiple myeloma, between 2005 and 2015 at a Lebanese hospital. RESULTS: Most of the isolated bacteria originated from urine (49%) followed by blood (30%) and were mainly Gram-negative (70%). Fluoroquinolone susceptibility was 57% among Gram-negative and Gram-positive isolates. Bacteremia was documented in 12.6% of the patients, with a predominant gram-negative etiology having 95% susceptibility to fluoroquinolones. The duration of neutropenia, < or > 7 days, did not affect the incidence of bacteremia (11% vs. 14% respectively, p = 0.17). Patients with lymphoma were more likely to have prolonged neutropenia compared to those with myeloma (p < 0.0001). The use of a central line and the development of central-line infections were significantly higher in Gram-positive bacteremia (p = 0.03, p = 0.008 respectively). Mucositis occurred more in Gram-negative bacteremia (p = 0.02). Total mortality rate was 3.7% in the whole population and that attributed to bacteremia was 12.5% in the bacteremia subgroup. Bacteremia was a predictor for mechanical ventilation (p = 0.003), septic shock and mortality (p = 0.025). CONCLUSION: Since organisms causing bacteremia were still highly susceptible to fluoroquinolones and that the duration of neutropenia post-AHSCT didn't affect bacteremia, we concluded that fluoroquinolone prophylaxis is still valid yet, with close monitoring of resistance.