| Hospitalization |
| Mechanical ventilation |
| Innate or acquired immunodeficiencies (neutropenia, human immunodeficiency virus [HIV]/acquired immunodeficiency syndrome [AIDS], malignancy) |
| Invasive medical procedures (surgery, transplantation) |
| Catheterization (urinary, central venous) |
| Burns, severe external injuries |
| Immunosuppressive therapy |
| Cancer chemotherapy |
| Radiotherapy |
| Diseases of the cardiovascular system |
| Diseases of the respiratory system (e.g., chronic obstructive pulmonary disease, cystic fibrosis) |
| Diabetes mellitus |
| Patients living in poor living conditions, malnutrition |
| Intravenous drug use |
