Detection and quantitation of the etiologic agents of ventilator-associated pneumonia in endotracheal tube aspirates from patients in Iran.

TO THE EDITOR—Pneumonia is the second most common nosocomial infection, accounting for approximately 18% of such infections. The mortality rate associated with nosocomial pneumonia can be decreased from 91.6% to approximately 30.5% if appropriate treatment is instituted. Critically ill patients who require mechanical ventilation support are at especially high risk of developing ventilator-associated pneumonia (VAP), which has an estimated annual incidence of l%-25% among hospitalized patients. Longer hospital stay, mortality, and morbidity are negative outcomes associated with VAP. The risk of pneumonia has been reported to be 6.5% among patients who receive ventilatory support for 10 days; this rate increases to 28% among patients who receive ventilatory support for 30 days." The most common noninvasive sampling technique for the diagnosis of VAP is endotracheal aspiration. Two invasive sampling methods are also common: protected-specimen brush sampling and bronchoalveolar lavage. Endotracheal aspiration is less expensive, compared with bronchoalveolar lavage or protected-specimen brush sampling. The threshold currently used for the diagnosis of pneumonia is 10 to 10 colony-forming units (cfu) of a pathogen per milliliter. This study sought to determine the different types and prevalences of organisms responsible for nosocomial VAP at our hospital in Iran, quantify the number of organisms isolated from endotracheal aspiration samples, and clarify the isolates' susceptibility patterns to common antibiotics.