Epidemiology, pathogenesis, microbiology, and diagnosis of hospital-acquired and ventilator-associated pneumonia in adults
- Thomas M File, Jr, MD
Thomas M File, Jr, MD
- Section Editor — Pulmonary Infections
- Professor of Medicine
- Northeast Ohio Medical University
Hospital-acquired (or nosocomial) pneumonia (HAP) and ventilator-associated pneumonia (VAP) are important causes of morbidity and mortality despite improved antimicrobial therapy, supportive care, and prevention.
The epidemiology, pathogenesis, and microbiology of HAP and VAP will be reviewed here. The diagnosis, risk factors, prevention, and treatment of HAP and VAP are discussed separately. (See "Clinical presentation and diagnosis of ventilator-associated pneumonia" and "Risk factors and prevention of hospital-acquired and ventilator-associated pneumonia in adults" and "Treatment of hospital-acquired and ventilator-associated pneumonia in adults".)
Pneumonia types — The 2016 Infectious Diseases Society of America/American Thoracic Society (IDSA/ATS) guidelines on the management of adults with hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) used the following definitions  (see 'Society guideline links' below):
●HAP (or nosocomial pneumonia) is pneumonia that occurs 48 hours or more after admission and did not appear to be incubating at the time of admission.
●VAP is a type of pneumonia that develops more than 48 to 72 hours after endotracheal intubation.
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