Pseudomonas cepacia in cystic fibrosis.

Pseudomonas cepacia, a Gram negative bacillus first described as a cause of soft rot in onions, is now recognised as an important opportunistic pathogen in altered hosts.' A distant relation of Pseudomonas aeruginosa, it is ubiquitous in the environment and frequently found in association with soil, water, and plants. It is a hardy organism, able to multiply in distilled water and survive in many medical disinfectants. Although virtually non-pathogenic in healthy individuals, those with altered defences have experienced infections of endocardium, blood, peritoneum, bone, joint, meninges, and lung.' The organism is inherently resistant to many antimicrobial drugs, making effective treatment difficult. The first report of Ps cepacia infection in patients with cystic fibrosis came from Philadelphia, USA in 1977;2 at this early stage an association with an adverse outcome for some of those infected was noted. A report of the isolation of Ps cepacia from patients with cystic fibrosis on the west coast of the USA was published in 1979.3 By 1982 carriage rates of45% were reported from one Canadian clinic,4 and in 1983 the same centre recognised a rapidly fatal outcome in a proportion of those who harboured the organism.5 Further work in this centre in 1985 confirmed the increased risk of death following acquisition of Ps cepacia in a case-control format.6 In the same year workers in Cleveland, Ohio described a range of responses to this infection no change in clinical status, an increased rate of decline of lung function, or rapid progression to death the latter being seen in 40% of their patients.7 The first report of the death of a patient with cystic fibrosis thought to be attributable to Ps cepacia infection in the UK appeared from Scotland in 1986.8 Four years later the first sizeable series was published from Leeds.9 Workers at this centre noted an increase in the prevalence of Ps cepacia infection from 1% to 8% over a six year period (1984-9) with a peak prevalence of 10% amongst 139 patients in 1988; they also commented on an adverse outcome for a proportion of those infected. In 1988 a lower prevalence of 4-1-5 9% was found in an adult cystic fibrosis clinic in London,'0 and in 1991 a 7% prevalence of Ps cepacia infection was reported from a paediatric centre in Manchester." In the USA attempts to investigate the epidemiology of this new pathogen in the cystic fibrosis field had focused on the possibility of patient-to-patient transmission, spurred on by the observation of a relatively high concordance for Ps cepacia infection amongst siblings.67 Attention was initially concentrated on the hospital environ-