Review article Does health care associated pneumonia really exist? Alejandra Lopez, Rosanel Amaro, Eva Polverino ⁎ Respiratory Disease Department, Hospital Clinic of Barcelona, IDIBAPS, Spain abstract article info Article history: Received 22 March 2012 Received in revised form 8 May 2012 Accepted 9 May 2012 Available online 2 June 2012 Keywords: Health care-associated pneumonia Pneumonia Respiratory infections Multidrug-resistant infections The most recent ATS guidelines for nosocomial pneumonia of 2005 describe a new clinical category of patients, Health Care-Associated Pneumonia which includes a number of very heterogeneous conditions possibly associ- ated with a high risk of multi-drug resistant (MDR) infections and of mortality. This paper aims at reviewing the current literature on HCAP and examines the controversial issues of HCAP etiology and outcomes, underlining the need of a profound revision of the HCAP concept in the face of the poor and contrasting scientific evidence supporting its basis. © 2012 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. 1. Introduction The last American classification of pneumonia of 2005 [1] includes community-acquired pneumonia (CAP), hospital-acquired pneumo- nia (HAP), ventilator-associated pneumonia (VAP), and health care associated pneumonia (HCAP). In particular, the definition of HCAP includes patients with one or more of the following conditions: resi- dence in nursing homes (NH) or long-term care facilities (LTCF), chronic dialysis, home infusion therapy, previous hospitalization in the last 3 months, wound care, and a family member with multi- drug resistant (MDR) pathogen (Table 1). This new clinical entity (HCAP) indirectly reflects substantial pro- gresses in health care system organization and settings, and profound demographic (life expectancy) and socio-cultural changes in the gen- eral population [2–4]. In fact, the general need to reduce acute-care hospital workload and to improve quality of care by stratifying levels and sites of care has led to an increased number of ambulatory patients (chemothera- py, dialysis, etc.), individuals residing in long-term care facilities or receiving wound care or infusion therapy at home in the last decades. All these factors have contributed to the definition of a new and expanding class of patients developing infections in a non-hospital environment but in regular contact with the health care system. The possible origin of HCAP definition is the prior study of Friedman et al. showing that bacteremia associated with health care was similar to hospital-acquired infections in terms of frequency of various comor- bid conditions, source of infection, pathogens and their susceptibility patterns, and mortality rate at follow-up and requirement of a targeted therapeutic approach [5]. The same group (Friedman et al.) [5] therefore proposed a classi- fication for bloodstream infections that distinguished community- acquired, nosocomial, and health care-associated infections, with HCAI criteria almost identical to those of current HCAP definition. Later on, the studies from Kollef et al. in USA on large series of positive-culture HCAP consolidated the concept of HCAP by showing that the microbial etiology was similar to that of HAP [6,7]. The concept of HCAP was therefore initially based on three funda- mental elements: (1) A subgroup of pneumonia acquired in the community (HCAP) could be in reality caused by nosocomial and/or MDR micro- organisms (Pseudomonas aeruginosa, Staphylococcus aureus, Gram negative bacilli, etc.); (2) Patients with HCAP could experience a treatment failure due to an initial inadequate antibiotic coverage if directed at usual CAP pathogens, with an associated increased risk of mortality; (3) Therefore, HCAP patients should be correctly identified and promptly treated with broad-spectrum antimicrobial therapy covering possible MDR pathogens [1]. Unfortunately, the methodological heterogeneity of most studies published on HCAP since then (study design, population composition, microbiological criteria, etc.) has raised more confusion than under- standing in many aspects such as the microbial etiology, the definition of risk factors for MDR infections and the indications for empiric antibi- otic treatment. Another fundamental element discrediting the current “HCAP concept” [1] is the fact that it includes a heterogeneous group of patients with a wide variety of conditions and also, in some studies, patients with clear immunosuppression [7]. European Journal of Internal Medicine 23 (2012) 407–411 ⁎ Corresponding author at: Respiratory Disease Department, Hospital Clinic of Barce- lona, IDIBAPS, Calle Villarroel 170, 08036 Barcelona, Spain. Tel./fax: + 34 932275549. E-mail address: epolveri@clinic.ub.es (E. Polverino). 0953-6205/$ – see front matter © 2012 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.ejim.2012.05.006 Contents lists available at SciVerse ScienceDirect European Journal of Internal Medicine journal homepage: www.elsevier.com/locate/ejim