Low incidence of multidrug-resistant organisms in patients with healthcare-associated pneumonia requiring hospitalization

Healthcare-associated pneumonia (HCAP) includes a broad spectrum of patients who acquire pneumonia through outpatient contact with the health system. Although limited prospective data exist, it has been suggested that all patients with HCAP should receive empirical therapy with a multidrug regimen directed against drug-resistant organisms. We aimed to determine the differences in aetiology and outcomes between HCAP groups and a community-acquired pneumonia (CAP) group, and to assess the presence of antibiotic-resistant bacteria. All consecutive non-immunocompromised adults hospitalized with pneumonia were prospectively included from 2001 to 2009. Patients who had had recent contact with the health system through nursing homes, home healthcare programmes, haemodialysis clinics or prior hospitalization were considered to have HCAP. A total of 2245 patients with pneumonia were hospitalized through the emergency room, of whom 577 (25.7%) had HCAP. Significant differences in causative pathogens were found between groups. Antibiotic-resistant organisms, including methicillin-resistant Staphylococcus aureus, resistant strains of Pseudomonas aeruginosa, and extended-spectrum beta-lactamase-producing Enterobacteriaceae, were scarce in all groups. In contrast, aspiration pneumonia was particularly frequent. No differences were found regarding inappropriate initial empirical antibiotic therapy between groups. Overall mortality was higher in patients who attended a hospital or haemodialysis clinic or received intravenous chemotherapy in the 30 days before pneumonia, and among patients who resided in a nursing home or long-term-care facility. In conclusion, most HCAP patients could be treated in the same way as patients with CAP, after carefully ruling out the presence of aspiration pneumonia.