Clinical features of healthcare-associated pneumonia (HCAP) in a Japanese community hospital: Comparisons among nursing home-acquired pneumonia (NHAP), HCAP other than NHAP, and community-acquired pneumonia

Background and objective: More than 100 000 Japanese die of pneumonia every year. The number of people residing in nursing homes is increasing with the ageing of the population. In 2005, the American Thoracic Society/Infectious Diseases Society of America (ATS/IDSA) published important guidelines for the management of healthcare-associated pneumonia (HCAP). In Japan, however, the optimum strategy for management of HCAP is still unclear. The purpose of this study was to clarify the clinical features of patients with HCAP. Methods: Patients (n = 202) who were consecutively admitted with a diagnosis of acute pneumonia between October 2007 and September 2009 were retrospectively evaluated. Using the ATS/IDSA guidelines, patients were divided into three groups: a community-acquired pneumonia (CAP) group (n = 123), a nursing home-acquired pneumonia (NHAP) group (n = 46) and a HCAP other than NHAP (O-HCAP) group (n = 33). These groups were then compared with respect to laboratory data, microbiological findings and mortality. Results: Thirty-day mortality in the NHAP group (10.9%) tended to be higher than that in the CAP group (3.3%) or the O-HCAP group (0%). The pathogens most frequently identified were Streptococcus pneumoniae and Haemophilus influenzae in the CAP group, methicillin-resistant Staphylococcus aureus and Klebsiella pneumoniae in the NHAP group, and S. pneumoniae and K. pneumoniae in the O-HCAP group. Conclusions: The NHAP group was clinically different from the O-HCAP group, based on bacteriological examination and mortality rates. In order to accurately diagnose, and formulate optimum treatment strategies for Japanese patients, the categories of HCAP, as specified in the ATS/IDSA guidelines, should not be applied directly either to patients with NHAP or those with O-HCAP.