Version May 2024
| Term | Definition |
| Classification by site of acquisition | |
| Community-acquired pneumonia (CAP) | An acute infection of the pulmonary parenchyma acquired outside of health care settings |
| Nosocomial pneumonia | An acute infection of the pulmonary parenchyma acquired in hospital settings, which encompasses hospital-acquired pneumonia and ventilator-associated pneumonia |
| Hospital-acquired pneumonia (HAP) | Pneumonia acquired ≥48 hours after hospital admission; includes both HAP and VAP |
| Ventilator-associated pneumonia (VAP) | Pneumonia acquired ≥48 hours after endotracheal intubation |
| Health care-associated pneumonia (HCAP) | Retired term, which referred to pneumonia acquired in health care facilities (eg, nursing homes, hemodialysis centers) or after recent hospitalization* |
| Classification by etiology | |
| Atypical pneumonia | Pneumonia caused by "atypical"¶ bacterial pathogens including Legionella spp, Mycoplasma pneumoniae, Chlamydia pneumoniae, Chlamydia psittaci, and Coxiella burnetii |
| Aspiration pneumonia | Pneumonia resulting from entry of gastric or oropharyngeal fluid, which may contain bacteria and/or be of low pH, or exogenous substances (eg, ingested food particles or liquids, mineral oil, salt or fresh water) into the lower airways |
| Chemical pneumonitis | Aspiration of substances (eg, acidic gastric fluid) that cause an inflammatory reaction in the lower airways, independent of bacterial infection |
| Bacterial aspiration pneumonia | An active infection caused by inoculation of large amounts of bacteria into the lungs via orogastric contents |
* The term HCAP was used to identify patients at risk for infection with multidrug-resistant pathogens. This categorization may have been overly sensitive, leading to increased, inappropriately broad antibiotic use.
¶ The origin of the term "atypical" is a matter of debate. The term may refer to the fact that these organisms are not "typical" bacteria, which cannot be identified by standard microbiologic techniques. Others suggest that atypical refers to the mild nature of the pneumonia caused by some of these organisms compared with pneumonia caused by Streptococcus pneumoniae.آیا می خواهید مدیلیب را به صفحه اصلی خود اضافه کنید؟
