HEPA Air Filtration Reduces Risk of Hospital Aspergillus Infections

Aspergillus is a common indoor and outdoor mold (fungus) which grows in soil, compost, wood, food and many moist indoor surfaces.  Aspergillus produces a large number of allergic proteins (allergens) and toxic chemicals (called mycotoxins).  Aspergillus can also cause life threatening infections in people with compromised immune systems such as people with leukemia or lymphoma, with HIV/AIDS, on immunosuppressive drugs for organ/ bone marrow transplants or severely malnourished.  Aspergillus infection rates have been increasing rapidly in recent decades and now kill over 10,000 annually in the USA.

Aspergillus spores are most commonly spread through the air, but can also be spread by water, food or by physical contact.   A number of studies have reported that the use of HEPA (High Efficiency Particulate Air) filters are associated with significantly lower rates of Aspergillus infection and Aspergillus infection deaths in hospitals.  A recent Singapore study reported that installation of portable HEPA filters in hospital rooms cut the Aspergillus infection rates by 50%. This research by Salam et al. is now in press in the American Journal of Infection Control.

Many good air filters are available for home use- including HEPA filters and machines that clean the air via electrostatic precipitation.  Such filters can significantly reduce the levels of mold and bacteria spores in the air.