Microbial colonization in a new intensive care burn unit. A prospective cohort study.

Renovation of an existing intensive care burn facility required closure for ten months. An interim eight-bed open intensive care ward (B) was established in a burn convalescence ward. The renovated unit (A) contained nine single-bed intensive care rooms and seven intermediate-level care beds in four rooms. Patients admitted to unit A were treated as a cohort. The first 25 admissions to unit A and the last 25 admissions to ward B meeting the inclusion criteria were compared. Microbial colonization was monitored by a fixed protocol of admission and multiple weekly sputum, wound, stool, and urine cultures. During intensive care, both cohorts exhibited the same incidence of gram-negative wound, sputum, and urine colonization. Occurrence of antibiotic-resistant organisms was the same. No evidence of bacterial cross-contamination was observed between A and B. A continuation of Providencia stuartii and Pseudomonas aeruginosa (type 15) endemics occurred in B. The collected data demonstrate that the A cohort was colonized with new, similar but distinct gram-negative organisms and indicate that cohort separation may be a practical way of eliminating endemic resistant gram-negative organisms from burn units.