Nosocomial Outbreak of Pseudomonas cepacia Associated with Contamination of Reusable Electronic Ventilator Temperature Probes

Abstract

Objective: The investigation and control of an outbreak of nosocomial Pseudomonas cepacia respiratory tract colonization and infection. Design: Epidemiologic investigation based on infection control surveillance data, including definition and characterization of case patients, environmental cultures based on epidemiologic information, and institution of control measures based on study results. Setting: A 1, 171-bed, university-affiliated tertiary care hospital. Results: Between January 1, 1988, and June 30, 1989, 127 patients were culture-positive for P cepacia, 117 (92%) of whom were culture-positive from sputum and were treated in the intensive care unit. Review of respiratory care procedures revealed that when mechanical ventilators were serviced between patients, the electronic temperature probes used with servo-controlled humidifiers were wiped with the same odor-counteractant cleaning solution used on ventilator cabinets. P cepacia was isolated from nine of 12 in-use temperature probe tips, three of which were from patients with negative sputum cultures for P cepacia, one of whom subsequently developed culture positivity for P cepacia. P cepacia also was isolated from the diluted odor-counteractant solution. Following the institution of a disinfection procedure for temperature probe tips, the incidence of P cepacia sputum culture positivity in ICU patients fell significantly compared to the outbreak period (138 of 5,225 discharges versus 52 of 3,678 discharges, P<0.01). Conclusions: This investigation identified contamination of reusable electronic temperature probes as a source of nosocomial respiratory infection due to P cepacia and emphasizes the need to carefully evaluate disinfection practices for reusable patient care equipment.