Introduction: Children with acute lymphoblastic leukaemia (ALL) are treated with intensive chemotherapy, which results in profound immunosuppression. Treatment with trimethoprim/sulphamethoxazole (TMP-SMX) is therefore used in some departments as prophylaxis against infections with both bacteria and Pneumocystis carinii. The use of TMP/SMX for prophylaxis during the induction therapy is not uniform in the four departments of paediatric oncology in Denmark. This gave us the opportunity to describe the effect of TMP/SMX on bacterial infections in children with ALL during the induction therapy.
Material and methods: Between 1 January 1992 and 31 December 1997, 210 children were diagnosed with ALL in Denmark. From a retrospective review of the medical charts, the number of children with fever (> 38 degrees C), the number of febrile days, days of antibiotic treatment, and the number of positive blood cultures were registered for each febrile episode.
Results: One hundred and fourteen children received TMP/SMX prophylaxis (10-30 mg/SMX/kg/day) and 76 did not. Children who received TMP/SMX prophylaxis had significantly fewer episodes of fever (66/114 (58%) vs. 60/76 (79%), p < 0.01) and significantly fewer children who received the prophylaxis had positive blood cultures before the start of antibiotic treatment compared with children who did not receive prophylaxis (23/114 (20%) vs 37/76 (49%), p < 0.001)). Nineteen different species were isolated from the blood stream before the start of antibiotic treatment. In the non-prophylaxis group there were a preponderance of isolates with Staph. aureus, Str. pneumoniae, E. coli, and P. aeruginosa. There was no difference in the mortality between the two groups (p = 0.44). There were no cases of P. carinii pneumonia in the period of induction therapy.
Discussion: TMP/SMX prophylaxis during induction therapy for childhood ALL seems to reduce the risk of bacteraemias and febrile illness.