[Long-term follow-up of children with urinary tract infection: bacterial spectrum, E. coli-serotypes 0, relapse, and reinfection (author's transl)].

Within 4 years 1400 children were investigated for urinary-tract infection in a long-term study. Children with manifest infection were treated and followed-up. In 59 children with chronic pyelonephritis 159 recurrences were observed: 146 were reinfections (change of organism) and 13 relapses (organism unchanged). Serotyping of 0-antigens showed differences between children with chronic pyelonephritis and children with a single exacerbation within the observation period. Reinfection with resistant bacteria mainly occurred shortly after cessation of therapy.