Background and purpose: Children with acute lymphoblastic leukemia are treated with intensive chemotherapy resulting in profound immuno suppression. Therefore treatment with trimethoprim-sulfamethoxazole (TMP-SMX) may be used for prophylaxis against infections both with bacteria and Pneumocystis carinii in some departments. The use of TMP-SMX for prophylaxis during the induction therapy is not uniform in the four departments of pediatric 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 January 1st 1992 and December 31st 1997, 210 children were diagnosed with ALL in Denmark. Based on 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 every 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%) v 60/76 (79%), p <0,01), and significantly fewer children who received TMP/SMX prophylaxis had positive blood cultures before 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 start of antibiotic treatment. In the non-prophylaxis group there was 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.
Conclusion: TMP/SMX prophylaxis during induction therapy for childhood ALL seems to reduce the risk of bacteremias and febrile illness.