Impact of multidrug resistant bloodstream infection burden, prophylactic levofloxacin and rectal swab practice on children with high-risk leukemias.

OBJECTIVE

Aim: To determine the prevalence of multidrug-resistant rectal colonization and bloodstream infection in children with high-risk leukemia receiving levofloxacin prophylaxis, to assess changes in fluoroquinolone susceptibility across chemotherapy cycles, and to examine concordance between rectal surveillance cultures and bloodstream infection.

PATIENTS AND

METHODS

Materials and

Methods

This retrospective cohort included 82 children aged 18 years or younger with acute myeloid leukemia or relapsed acute lymphoblastic leukemia treated with intensive chemotherapy and levofloxacin prophylaxis. Rectal swabs were obtained during febrile neutropenia when available, blood cultures were obtained for all febrile neutropenia episodes, and empirical meropenem was modified according to culture results. Multidrug resistance was classified according to published consensus criteria.

RESULTS

Results

Median age was 10 years, 67.1% were male, and 82.9% had acute myeloid leukemia. Febrile neutropenia occurred in 89.3% of chemotherapy cycles. Rectal colonization was dominated by multidrug-resistant Klebsiella species and multidrug-resistant Escherichia coli. Bloodstream infection was dominated by multidrug-resistant Klebsiella pneumoniae and multidrug-resistant Escherichia coli. Fluoroquinolone susceptibility was low in both rectal isolates (16%) and bloodstream isolates (11.8%) and decreased further across successive cycles. Mortality was associated with multidrug-resistant Klebsiella pneumoniae bloodstream infection and fluoroquinolone resistance in bloodstream isolates.

CONCLUSION

Conclusions

In this resistance setting, routine levofloxacin prophylaxis appears to offer limited benefit and may promote rapid expansion of resistant gramnegative flora. Rectal surveillance together with culture-directed therapy may better support antimicrobial stewardship and early risk-adapted treatment.