Aetiology of VAP

In Australia, ventilator-associated pneumonia (VAP) is caused by similar pathogens to those implicated in hospital-acquired pneumonia (HAP) (eg gram-negative bacteria; see Aetiology of HAP). However, the aetiology of VAP can vary with location, so awareness of local epidemiology is useful. Some centres have a higher prevalence of Pseudomonas aeruginosa and Staphylococcus aureus. In many Australian hospitals, nosocomial methicillin-resistant S. aureus (MRSA) infections are uncommon.

Although viruses are not considered to be a common cause of VAP, there is increasing recognition of nosocomial transmission of respiratory viruses (eg severe acute respiratory syndrome coronavirus 2 [SARS-CoV-2], influenza, respiratory syncytial virus [RSV]).

Although Candida species¹ can colonise the respiratory tract of hospitalised patients, they rarely, if ever, cause VAP.

¹ Some yeast species that were previously considered Candida species have been reclassified and are now considered candida-like and may be reported with a new name (eg Nakaseomyces glabratus, Pichia kudriavzevii)Borman, 2021. For a list of common Candida and related species and (if applicable) revised species names, see Common Candida and related species, and changes to nomenclature.Return