AN OUTBREAK OF BURKHOLDERIA (FORMERLY PSEUDOMONAS) CEPACIA RESPIRATORY-TRACT COLONIZATION AND INFECTION ASSOCIATED WITH NEBULIZED ALBUTEROLTHERAPY

Objective: To investigate an outbreak of Burkholderia (formerly Pseudo monas) cepacia respiratory tract colonization and infection in mechani cally ventilated patients. Design: A retrospective case-control and ba cteriologic study, Setting: Veterans Affairs medical center. Patients: 42 mechanically ventilated patients who developed respiratory tract c olonization or infection with B. cepacia and 135 ventilator-dependent controls who were not colonized and did not develop infections. Measur ements: Clinical and demographic data; benzalkonium chloride concentra tions and pH levels in albuterol sulfate solutions; repetitive-element polymerase chain reaction (PCR)-mediated molecular fingerprinting on eight patient isolates and three environmental B. cepacia isolates tha t were available for study. Results: 42 patients had B. cepacia respir atory tract colonization or infection. Observation of intensive care u nit and respiratory care personnel showed faulty infection control pro cedures (for example, the same multiple-dose bottle of albuterol was u sed for many mechanically ventilated patients). More case patients (39 [92.9%]) than controls (95 [70.4%]; P = 0.006) received nebulized alb uterol, and case patients (67.5 treatments) received more treatments t han controls (18 treatments; P < 0.001). In-use albuterol solutions ha d pH values that were unstable, and benzalkonium chloride concentratio ns declined over time to levels capable of supporting bacterial growth . Medication nebulizers and in-use bottles of albuterol harbored B. ce pacia. Molecular fingerprints of patient isolates and environmental B. cepacia isolates were identical using repetitive-element PCR. No furt her isolates of B. cepacia were identified after institution of approp riate infection control procedures. Conclusions: Multiple-dose medicat ions and reliance on benzalkonium chloride as a medication preservativ e provide a mechanism for nosocomial spread of microorganisms, particu larly if infection control procedures are not carefully followed. Repe titive-element PCR is a useful fingerprinting technique for molecular epidemiologic studies of B. cepacia.