Abstract
In a double-blind trial 45 children aged 6 months to 14 years with Escherichia coli infections of the urinary tract were given co-trimoxazole for two weeks and then allotted at random to one of two treatment groups for the remainder of six months; one continued with the active drug and the other with dummy tablets of identical appearance. Of the 24 children who took co-trimoxazole for two weeks and the 21 who took it for six months, 11 and 10, respectively, remained without further infections for at least a year. Over 90% of the reinfections occurred within five months of stopping the antibiotics, and the longer treatment did not cause any delay in their appearance. Thus probably a six-month course of treatment is no more likely to achieve a cure than a two-week course; nevertheless, no infection occurred during treatment, and there may be an advantage in continuing with antibiotics in small dosage.