The risk of infection for cystic fibrosis patients from Burkholderia cepacia complex pathogens is of increasing concern to doctors and scientists. This paper reports on how these patients perceive and manage the risk of cepacia infection using Douglas and Calvez's (1990) typology of four cultures of the community (the central community, dissenting enclaves, isolates, and individualists) and Douglas' works on pollution, risk, and culture. We attempt to develop Douglas's cultural theory in the light of the data, which were drawn from in-depth interviews with 31 adults with cystic fibrosis attending a specialist treatment centre in the UK. We found that our respondents' group membership depended on their health state and contact with the hospital. The central community of adults was found to be dispersing to form a series of isolates, perceiving others who may potentially have infection as individualists. Due to the nature of cepacia infection, no dissenting enclave was identified for this group. Medical and lay uncertainty in testing for infection and managing the risk of its spread was expressed by the majority of adults, many of whom admitted that they limited hospital attendance as a part of managing such risk.