Aspergillus is a filamentous mould ubiquitous in the environment and the concentration of its spores in the air varies according to weather conditions and seasons. In this regard, efforts are often made to limit its diffusion in wards where fragile patients are housed (e.g., ICU, Haematology, Oncology, etc.). Indeed, in these patients, Aspergillus infections can present as pulmonary aspergillosis, invasive rhinosinusitis or angio-invasive aspergillosis with significantly high rates of morbidity and mortality, while it rarely causes disease in healthy immunocompetent subjects.

Previous studies have established the correlation between nasal carriage of microorganisms and the development of an invasive infectious disease; however, those studies mainly focused on Staphylococci and Candida species.

The main target of this study is to investigate the spread of Aspergillus within a hospital ward and analyse the correlation between nosocomial infection and symptom severity in a cohort of frail population.

Inclusion Criteria:

• ≥ 18 years old
• Signature of informed consent
• Admission to San Matteo's Hematology ward

patients admitted to the Hematology ward