Endemicity and inter-city spread of Burkholderia cepacia genomovar III in cystic fibrosis

Objectives: We sought to determine whether the same Burkholderia cepacia complex strain has persisted as the dominant clonal lineage among patients in a large cystic fibrosis (CF) treatment center during the past 2 decades. Study design: The inter-city spread of B cepacia through transfer of a colonized patient and the impact of infection control measures in containing interpatient transmission were investigated. We analyzed all available B cepacia complex isolates recovered from 1981 to 1987 and from 1996 to 2000 at one large CF treatment center (Center A) and from 1997 to 2000 at another center (Center B). Incidence of B cepacia complex infection and infection control measures in both centers were assessed. Results: Seventeen (81%) of 21 Center A patients from whom B cepacia. complex bacteria were recovered between 1981 and 1987 and 40 (97%) of 41 patients culture-positive between 1996 and 2000 were infected with the same genomovar III strain. Transfer of a colonized patient from Center A to Center B was associated with an increase in B cepacia complex infection in Center B, all of which was with the Center A dominant strain. This strain, designated PHDC, lacks both B cepacia epidemic strain and cblA markers. Conclusions: B cepacia complex strains may remain endemic in CF treatment centers for many years. Responsible bacterial and host factors and optimal infection control measures to prevent inter-patient spread remain to be identified.