Nosocomial pneumonia: epidemiology and infection control.

Elderly, debilitated, or critically ill patients are at high risk for hospital acquired or nosocomial respiratory tract infection. Gram-negative bacilli, Staphyloccoccus aureus, and anaerobes colonizing the oropharynx are the most frequent etiologic agents. Colonization of the oropharynx may be related to the patient's age, underlying disease, nutritional status, prior exposure to antibiotics, supine position, and gastric colonization. Nosocomial pathogens may also be acquired from the hands of hospital personnel, contaminated equipment or fluids. The absence of sensitive and specific methods for accurate diagnosis remain a concern. Despite treatment with appropriate antimicrobial therapy, there is a high mortality and morbidity. Measures for the prevention of nosocomial pneumonia should include compliance with infection control principles, appropriate use of antibiotics, proper patient position, and removal of potential sources of cross colonization.