What is hospital-acquired pneumonia (HAP)?

Updated: Apr 15, 2021
  • Author: Kartika Shetty, MD, FACP; Chief Editor: John L Brusch, MD, FACP  more...
  • Print


Pneumonia is defined as "new lung infiltrates plus clinical evidence that the infiltrate is of an infectious origin, which include the new onset of fever, purulent sputum, leukocytosis, and decline in oxygenation." [1]

Hospital-acquired pneumonia (HAP), or nosocomial pneumonia, is a lower respiratory infection that was not incubating at the time of hospital admission and that presents clinically 2 or more days after hospitalization. Pneumonia that presents sooner should be regarded as community­ acquired pneumonia. VAP refers to nosocomial pneumonia that develops among patients on ventilators. [2, 1]  Ventilator-associated pneumonia (VAP) is defined as pneumonia that presents more than 48 hours after endotracheal intubation.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!