Cumulative antimicrobial susceptibility data for a tertiary-level paediatric oncology unit in Johannesburg, South Africa

Abstract

Background: There is global concern regarding the spread of antimicrobial resistance in bacteria and fungi. Oncology patients are at particular risk of infections with multidrug resistant organisms. These patients require urgent initiation of empiric antimicrobial therapy when presenting with neutropenic fever. Currently, piperacillin-tazobactam and amikacin with or without vancomycin is the treatment of choice in the unit.

Aim: The purpose of this study was to develop a cumulative antibiogram for the paediatric oncology unit at Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) to guide empiric treatment recommendations for patients presenting with suspected bacterial or fungal infection.

Setting: Tertiary-level paediatric oncology unit.

Methods: A retrospective observational analysis was performed of bacterial and fungal antimicrobial susceptibility data extracted from the microbiology laboratory information system for clinical specimens submitted from the paediatric oncology unit at CMJAH. Data was analysed for the period January 2015 to May 2018. In addition, analysis and comparison of two 17-month time periods was performed in order to elicit any changes over time.

Results: Klebsiella pneumoniae and Escherichia coli were the most common gram-negative organisms isolated. Twenty-one percent of Enterobacteriaceae showed resistance to third generation cephalosporins and 9% to carbapenems. Rates of carbapenem-resistant isolates decreased significantly over time. Adding amikacin to piperacillin-tazobactam significantly increased bacterial coverage. Coagulase-negative staphylococci and Candida parapsilosis were the most common gram-positive and fungal isolates recovered during the study.

Conclusion: The results support the continued use of piperacillin-tazobactam and amikacin for paediatric oncology patients presenting with neutropenic fever in this unit. Antibiograms are an important component of antimicrobial stewardship in conjunction with efficient infection prevention and control measures.