The most recent ATS guidelines for nosocomial pneumonia from 2005 identify a new clinical category of patients called Health CareAssociated Pneumonia that covers a number of extremely diverse illnesses that may be linked to a high risk of multi-drug resistant infections and of mortality. These researches attempts to analyses the existing HCAP literature and examine the contentious HCAP aetiology and results, highlighting the necessity for a significant modification of the HCAP concept in light of the underprivileged and conflicting scientific evidence underpinning its foundation
