Acute community-acquired pneumonia (CAP) refers to an acute infection of the lung parenchyma, occurring within the first 48 hours of hospitalization. It is a frequent, serious pathology with a strong economic impact. Viruses (rhinovirus, respiratory syncitial virus, influenza virus for the most common) and Streptococcus pneumoniae are the most frequently encountered pathogens. However, more than half of the PACs have no microbiological documentation. The management of CAPs is based on national and international recommendations. Several studies have shown imperfect compliance by clinicians with recommendations with a prognostic impact.

The various published studies insist on the variability of the incidence, the type of pathogen, the severity and the economic impact, depending on the series. They also insist on the need to know the local epidemiology, in particular microbiological, in order to adapt the recommendations.

The objective of the study is to determine the epidemiological, clinical, biological and imaging characteristics of people admitted for acute community-acquired pneumonia.

Inclusion criteria:

• Adult subject (≥ 18 years old),
• acute community-acquired pneumonia (< 48 hours after admission),
• admitted from the Emergency Department, consultation or home.
• Subject not objecting to the reuse of their data for scientific research purposes

Exclusion criteria:

• Expressed refusal to reuse data for scientific research purposes.
• bronchitis, acute nosocomial pneumopathy, secondary infection due to bronchial dilation.

Adult patients with acute community-acquired pneumonia (< 48 hours after admission),