Airborne bioaerosols in healthcare facilities – Transmission routes and mitigation strategies. A review

Public buildings, especially healthcare facilities, and their occupants are particularly vulnerable to the presence of various pathogens, including viruses, bacteria and fungi. Moreover, hospitals and outpatient clinics are places where the number of pathogens is very high. They are very often responsible for secondary infections due to improper use of these premises and the lack of adequate and efficient ventilation systems . This article therefore attempts to analyze these issues, with particular reference to the identification of pathogens in different hospital wards, the ways in which they are transmitted, both by humans and by natural and mechanical ventilation systems, and to identify the best ways to protect healthcare facilities against the spread of pathogens. The literature review identified a lack of clear guidelines for collecting data on the risk of pathogens in hospitals and their acceptable levels. Data on the presence of pathogens in hospitals are limited, published regionally and very often do not allow a full identification of risk. In addition, it has been shown that the best way to reduce the incidence of pathogens in hospitals is through the combined use of modern ventilation systems with high efficiency particulate air filters (HEPA), and by additional air purification with UV or plasma-based lamps. Recent studies have also shown a high level of efficiency in the inhibition of pathogens by modifying the surface of HEPA filters or garments with TiO 2 nano-oxide coatings in combination with particles of silver or copper.