Feasibility of selected prophylactic barriers in arrestance of airborne bacterial vegetative cells and endospores

Background: Transmission of infection by airborne agents is a risk for health care personnel, patients, and visitors. This risk is heightened in regions without access to environmental controls and personal protective equipment. The ability of 2 prophylactic barriers (ie, semitransparent netting for insect control) to arrest bioaerosols was assessed for potential use within the malarial zones. Methods: Barriers (pore sizes of 0.8 mm and 0.25 mm) were challenged with bioaerosols of vegetative cells and endospores of Bacillus anthracis strain Sterne 34F2 using a bioaerosol chamber. Barriers were also challenged with airborne inert polystyrene latex particles of known diameters (0.1, 0.43, 0.6, 1.3, 3.2, and 8.0 μm), and the arrestance provided by barrier with the 0.25 mm pore size was expressed as a function of aerodynamic diameter of challenge aerosols. Results: Barrier with the 0.8 mm pore size provided no significant arrestance of aerosols, whereas the barrier with the 0.25 mm pore size provided an 8% arrestance of vegetative cells and a 13% arrestance of endospores. No arrestance at or below the 0.6 μm particle size was observed. Conclusion: The level of arrestance provided by these prophylactic barriers does not justify their use as a sole method of preventing transmission.