Table 1.
Major pathogens and risk factors for pneumonia in community and LTCFs.
| Pathogens | Prevalence of CAP in community elderly (%) | Prevalence of pneumonia in LTCFs elderly | Risk factors |
|---|---|---|---|
| S. pneumoniae (Mufson and Stanek, 1999; Waterer et al., 2001; Martinez et al., 2003; Baddour et al., 2004) | 5–58 | 4–55 | Used lactams, fluoroquinolones, macrolides in the past 3 months; COPD; History of pneumonia in past 12 months; Aspiration. |
| H. influenzae (Lau et al., 2006; Jean et al., 2009; Kuo et al., 2014) | 2–29.4 | 0–22 | Severe underlying disease; Used antibiotics in the past 3 months; |
| Staphylococcus aureus (Wunderink et al., 2003; Bernardo et al., 2004; Stevens et al., 2007; Kalil et al., 2013; Bradley, 2014) | 0–7 | 0–33 | Hospitalized in the past 3 months; Used antibiotics in the past 3 months; Living in LTCFs; Received intravenous therapy or dialysis for the past 30 days; Confirmed MRSA by etiological diagnosis; Comorbidity; Mental disorders. |
| Legionella (Miller, 1981; Edelstein et al., 1996; Genne et al., 1997; Vergis et al., 2000; Blazquez Garrido et al., 2005; Mykietiuk et al., 2005; Sabria et al., 2005; Haranaga et al., 2007; Varner et al., 2011) | 0–17.5 | 0–6 | Smoking; Chronic disease; Immunosuppression; Air conditioning and hot water system use. |
| Gram-negative enteric bacilli (Ortiz-Ruiz et al., 2004; Yakovlev et al., 2006; Peto et al., 2014) | 0–12.4 | 0–14.3 | Living in LTCFs; Tube feeding; Comorbidity; Cerebrovascular disease; Dementia; Use of Proton pump inhibitors (PPIs). |
| Pseudomonas aeruginosa (Ding et al., 2016; Francois et al., 2017; Bassetti et al., 2018; Ocheretyaner and Park, 2018; Riquelme et al., 2018) | 1–17.1 | 0–6 | Hospitalized in the past three months; Used antibiotics in the past 3 months; Aspiration; Impaired swallowing; Use of PPIs; Structural lung disease or severe bronchiectasis; Confirmed pseudomonas aeruginosa in the past 12 months; Severe illness (requires ventilator or admission of ICU). |
| Chlamydia pneumonia (Arnold et al., 2016; Marchello et al., 2016; Perrone and Quaglia, 2017; Webley and Hahn, 2017) | 0–28 | 0–18 | |
| Mycoplasma pneumoniae (Cao et al., 2017; de Groot et al., 2017; Sharma et al., 2017; Waites et al., 2017b) | 1–13 | 1 |