Table 1.

Criteria for defining pneumonia

Radiological signs

Two successive chest radiographs showing new or progressive lung infiltrates  In the absence of medical history of underlying heart or lung disease, a single chest radiograph is enough

And at least one of the following signs

Body temperature > 38,3 °C without any other cause  Leucocytes < 4000/mm3 or ≥ 12,000/mm3

And at least two of the following signs

Purulent sputum  Cough or dyspnoea  Declining oxygenation or increased oxygen requirement or need for respiratory assistance