Moderate and severe CAP: diagnosis and management

Pneumonia is a common clinical disorder with an estimated incidence of 12 cases per 1000 population per year. In healthy individuals, many microorganisms colonise the nasopharynx and oropharynx. Microaspiration of contaminated secretions can cause infections in the lower airways. The glottal refl exes, the presence of complement proteins and immunoglobulins, the secretion of peptides with antimicrobial activities, and the inhibition of bacteria binding all protect the lower airways.36 The healthy microbiota of the upper airway also exert protection eff ects by competing with pathogens for nutritional resources and interacting with cellular receptors. The use of broad-spectrum antibiotics can modify the microbiota and predispose to infection.