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.HAP 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.HAP 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/μlIn 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.
Treatment
Patients with HCAP are more likely than those with community-acquired pneumonia to receive inappropriate antibiotics that do not target the bacteria causing their disease.In 2002, an expert panel made recommendations about the evaluation and treatment of probable nursing home-acquired pneumonia. They defined probably pneumonia, emphasized expedite antibiotic treatment (which is known to improve survival) and drafted criteria for the hospitalization of willing patients. For initial treatment in the nursing home, a fluoroquinolone antibiotic suitable for respiratory infections (moxifloxacin, for example), or amoxicillin with clavulanic acid plus a macrolide has been suggested. In a hospital setting, injected (parenteral) fluoroquinolones or a second- or third-generation cephalosporin plus a macrolide could be used. Other factors that need to be taken into account are recent antibiotic therapy (because of possible resistance caused by recent exposure), known carrier state or risk factors for resistant organisms (for example, known carrier of MRSA or presence of bronchiectasis predisposing to Pseudomonas aeruginosa), or suspicion of possible Legionella pneumophila infection (legionnaires disease).In 2005, the American Thoracic Society and Infectious Diseases Society of America have published guidelines suggesting antibiotics specifically for HCAP. The guidelines recommend combination therapy with an agent from each of the following groups to cover for both Pseudomonas aeruginosa and MRSA. This is based on studies using sputum samples and intensive care patients, in whom these bacteria were commonly found.