RISK OF CROSS-COLONIZATION AND INFECTION BY PSEUDOMONAS-AERUGINOSA INA HOLIDAY CAMP FOR CYSTIC-FIBROSIS PATIENTS

The risk of cross-colonization and subsequent infection by Pseudomonas aeruginosa in holiday camps for cystic fibrosis patients was studied in 91 children by culturing sputum at their arrival, at their departur e, 2 months later, and at regular intervals thereafter. The isolated s trains were subjected to serotyping, phage typing, pyocin typing, and genotyping by random amplified polymorphic DNA fingerprinting-PCR. It was concluded from random amplified polymorphic DNA fingerprinting-PCR typing that the Pseudomonas flora was not constant in most children. Some children harbored one genotype, whereas some harbored two or more different genotypes simultaneously. Most culture-positive children ea sily acquired a strain of another genotype which replaced the former o ne or coexisted with the original one. The incidence of sputum convers ion was 7.7% in previously negative children; the incidence of permane nt colonization and infection was 1.9%. This risk was comparable with that observed in the community. We conclude that the risk of cross-inf ection is trivial compared with the obvious joy and social benefit der ived from a holiday camp.