Infections of the Respiratory Tract
With its direct access to the outside, and the various sources of organisms, it is not surprising that the list of organisms that can cause disease in the respiratory tract is vast. Included are pneumococcus, Streptococcus pyogenes, Mycoplasma pneumoniae, Chlamydophila pneumoniae and Mycobacterium tuberculosis. Important viruses to consider are influenza, metapneumovirus, parainfluenza, respiratory syncytial virus (RSV) and the ‘common cold’ rhinoviruses. In countries where vaccination programmes are in place, infection caused by Corynebacterium diphtheriae (diphtheria), Bordetella pertussis (whooping cough) and Haemophilus influenzae serogroup b (childhood epiglottitis) are uncommon.