The changing microbial epidemiology in cystic fibrosis

Abstract

Infection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.

FIG. 1.

(A) Distribution of Burkholderia species among U.S. CF patients. The proportions of CF patients infected with various Burkholderia species are shown. The data are based on 2,024 CF patients who were infected with Burkholderia species and whose isolates were referred to the Burkholderia cepacia Research Laboratory and Repository (University of Michigan) between 1997 and 2007. “Other Bcc species” indicates patients infected with B. cepacia complex species other than those specified in the chart. “Indeterminate” refers to patients infected with strains that phylogenetically are members of the B. cepacia complex species but that cannot be definitively placed into one of the 17 defined species in this group. (B) Incidence of B. cenocepacia and B. multivorans infection in U.S. CF patients. The proportions of B. cepacia complex-infected CF patients who were first infected with either B. cenocepacia (red line) or B. multivorans (blue line) in the years indicated are shown.

FIG. 2.

Median predicted survival age for U.S. CF patients born in the years indicated. (Based on data derived from reference .)

FIG. 3.

Taxonomic changes in CF-relevant species. Solid arrows indicate changes in genus names. Dashed arrows indicate the identification of novel species based on a taxonomic assessment of “atypical” isolates within the species indicated.