BIOAEROSOLS: Role in Healthcare Institutions

Bioaerosols are airborne particles that are living or originate from living organisms (bacteria, viruses and fungi). In recent years a number of factors have stimulated an increased awareness of the presence of potentially pathogenic bioaerosols in hospital environments and the detrimental health effects associated with them. The incidence of hospital acquired infection is a serious and widespread problem, with an estimated 1 in 10 patients acquiring an infection during a hospital stay. There are a whole range of potentially pathogenic microorganisms associated with nosocomial infections many of which are opportunistic pathogens which frequently cause respiratory infections particularly in immunocompromised patients. The practical importance and frequency of airborne nosocomial infections has been a matter of dispute for many years. This is because most of the pathogens acquired in hospitals are able to use various different routes of infecting the patient's body so that it may be difficult or even impossible to prove an individual infection to be airborne. The assessment of indirect airborne infections caused by infective particles derived from dust introduced to the hospital environment is much more difficult. Many Gram-positive bacteria such as Staphylococcus aureus, mycobacteria, nocardiae, and endospores of clostridia and bacilli, as well as the reproductive elements of fungi do remain viable and infective in dry dust and may therefore infect patients when the dust is disturbed. In contrast to nosocomial infections due to Gram-negative bacteria, against which most preventive measures have been concentrated in the past and which are usually not airborne in origin, it appears that the possibility of direct or indirect transmission of hospital pathogens through bioaerosols has been underestimated. In the context of healthcare settings, bioaerosols can cause occupational hazards and nosocomial infections. Modern built environment can be a potential source of bioaerosols. Bioaerosol monitoring in hospitals can be used for tracking of nosocomial infections, identify the source and spread of airborne microorganisms to control hospital associated infections (HAI). This will also serve as a tool to measure biosafety while handling biohazardous materials. The complexity of these bio-aerosols requires a multidisciplinary approach. Their presence in air is the result of dispersal from a site of colonisation or growth. The evaluation of bio-aerosols includes use of variety of methods for sampling depending on the concentration of microorganisms expected. There is heightened awareness regarding the study of bioaerosols and its impact on human health and quality of indoor air and environment. This article is a review on role of bioaerosols in hospital environment.