POSITIVE SEROLOGY TO LEGIONELLA-LONGBEACHAE IN PATIENTS WITH ADULT-RESPIRATORY-DISTRESS-SYNDROME

In an observational study we measured the Legionella longbeachae antib ody titre rise in patients mechanically ventilated for more than eight days during a two-month period. The patients were divided into two gr oups on the basis of the presence or absence of the adult respiratory distress syndrome (ARDS). In nine patients with ARDS all showed an ant ibody rise consistent with recent infection with Legionella longbeacha e with a rise in titre (six patients) or a high titre after eight to t en days of ventilation (three patients). Three patients without ARDS d id not show a rise in titre. Culture of the environment, ventilator ci rcuits, humidifiers and humidification water did not reveal an environ mental source of Legionella longbeachae in the Intensive Care Unit. Le gionella longbeachae may be implicated as a pathogenic organism in ARD S, or as a secondary nosocomial infection. Alternatively the antibody titre rise may represent an epiphenomenon and may not be related to Le gionella longbeachae infection.