Is health care-associated pneumonia itself a predisposing factor for multi-drug resistant organisms?

Introduction: The concept and optimal treatment strategy for Health Care-Associated Pneumonia (HCAP) have been controversial in several studies. We aimed to evaluate the clinical features of HCAP patients hospitalized in a Korean teaching hospital and the risk factors for pneumonia caused by MDROs. Methods: This was a prospective observational study of patients admitted with CAP or HCAP to Seoul Medical Center in 2014. We compared clinical characteristics, comorbidities, severity, identified pathogens, antibiotics and clinical outcomes between the two groups. Results: A total of 106 patients were enrolled, consisting of 47 (44.3%) with HCAP and 59 (55.7%) with CAP. Among the HCAP patients, nursing home residence were 40 (85.1%), and 15 (31.9%) were those hospitalized in the preceding 90 days. The incidences of aspiration, and poor functional status were higher in the HCAP group. Although the HCAP patients showed higher PSI score, in-hospital mortality or ICU admission was not higher than CAP patients. Streptococcus pneumoniae (27.7%) was the most frequent pathogen in the HCAP group, followed by Staphylococcus aureus (19.1%). MDROs isolation was not different between HCAP and CAP groups (27.7% vs 13.6%, p=0.059). Pseudomonas aeruginosa was the most common MDRO in both groups. Multivariable analyses failed to show that the type of pneumonia was a predictable factor for MDROs. Only tube feeding (p=0.048) and prior hospitalization within one year (p=0.017) were associated with MDRO risk in hospitalized patients with HCAP or CAP. Conclusions: HCAP itself was not a predisposing factor for MDRO whereas hospitalization within one year and tube feeding were the risk factors.