Bacteraemia in a paediatric oncology unit in South Africa

To identify the morbidity and mortality due to infections in a South African paediatric oncology unit, and to identify risk factors associated with first bacteraemic episodes in this unit.

A retrospective cohort study was done in a large regional referral paediatric cancer centre from 1991-1995, of all consecutive patients with culture proven bacteraemia. Eighty-three oncology patients were studied (median age 4.0 years) in whom a total of 200 episodes of bacteraemia were recorded, of which 83 first bacteraemic episodes.

Of the 200 episodes 70% were caused by Gram-positive organisms, 20% by Gram- negative organisms and 10% by fungal organisms. Organisms associated with high mortality were Gram-negative organisms (Acinetobacter spp., Pseudomonas aeruginosa, Klebsiella species), and fungal organisms, (Candida parapsilosis). Seventeen out of 200 episodes ended in death of the patient. In 59% of patients Hickman catheters were in situ. The mean incidence of catheter related bacteraemia's was 3.3 episodes per 1000 catheter days. Seventy percent of first bacteraemic episodes occurred within 50 days after placement of the catheter. The generalized estimation equations model revealed that more Gram-negative infections occurred in the presence of a Hickman catheter (odds ratio 2.2, 95% CI 1.0-5.0). The presence of neutropenia and the use of parenteral nutrition were not associated with specific bacteraemic patterns.

Including all bacteraemic episodes in this cohort study a high incidence of fungal infections occurred of which 64% occurred with a Hickman catheter in situ. Candida parapsilosis had a higher incidence than reported in other centres. Secondly looking at first bacteraemic episodes a high incidence of Gram-negative infections was observed especially in the presence of a Hickman catheter.