In fact, the data collected by the authors indicated that the patients with HCAP are older than those with CAP (mean age, 81.3 years vs 69.7 years, respectively). Gram-negative pathogens and streptococci other than Streptococcus pneumoniae, Pseudomonas aeruginosa, and methicillin-resistant Streptococcus aureus were isolated more frequently in HCAP patients than in CAP patients. Silent aspiration is extremely common in the elderly patients, and aspiration during the night is the primary cause of pneumonia in the elderly. Oropharyngeal materials contain Gram-negative pathogens and streptococci, which are aspirated into the lower airways of patients with dysphagia. Hence, the severity of pneumonia and the occurrence of PDR pathogens were considerably affected by swallowing dysfunction rather than the locations where pneumonia had occurred.