hospital-acquired pneumonia hospital-acquired pneumonia hospital-acquired pneumonia (hap) or nosocomial pneumonia refers to any pneumonia contracted by a patient in a hospital at least 48–72 hours after being admitted. it is thus distinguished from community-acquired pneumonia. it is usually caused by a bacterial infection, rather than a virus. pneumonia as seen on chest x-ray. a: normal chest x-ray. b: abnormal chest x-ray with shadowing from pneumonia in the right lung (left side of image). hospital acquired pneumonia is the second most common nosocomial infection (after urinary tract infections) and accounts for 15–20% of the total. it is the most common cause of death among nosocomial infections and is the primary cause of death in intensive care units. it is also one of the most common infections acquired at the hospital in children around the world. hospital acquired pneumonia typically lengthens a hospital stay by 1–2 weeks. signs and symptoms new or progressive infiltrate on the chest x-ray with one of the following: fever > 37.8 °c (100 °f) purulent sputum leukocytosis > 10,000 cells/μl in an elderly person, the first sign of hospital-acquired pneumonia may be mental changes or confusion. other symptoms may include: a cough with greenish or pus-like phlegm (sputum) fever and chills general discomfort, uneasiness, or ill feeling (malaise) loss of appetite nausea and vomiting sharp chest pain that gets worse with deep breathing or coughing shortness of breath decreased blood pressure and fast heart rate types bacterial pneumonia: the majority of cases related to various rod shaped gram-negative organisms (52%) and staphylococcus aureus (19%), usually of the mrsa type. others are haemophilus spp. (5%). in the icu results were s. aureus (17.4%), pseudomonas aeruginosa (17.4%), klebsiella pneumoniae and enterobacter spp. (18.1%), and haemophilus influenzae (4.9%). viral pneumonia: influenza and respiratory syncytial virus and, in the immunocompromised host, cytomegalovirus – cause 10–20% of infections. ventilator-associated pneumonia