ABSTRACT
Pneumonia is an infection of the lung tissue itself, whereas bronchitis is an infection of the air passages leading into the lung. A large number of different micro-organisms can cause pneumonia. These include bacteria, viruses and fungi. Because of the variety and number of micro-organisms and their differing sensitivities to antibacterial drugs (antibiotics), it is important to try to identify the cause so that the appropriate antimicrobial agent can be given. However, because pneumonia is a serious condition and identification of the causative organism takes time, it is essential that therapy is started on a ‘best guess’ basis, depending upon where the infection was acquired, the clinical presentation and the chest X-ray appearance, before results of cultures are available.
