Respiratory protection: SARS advice from CDC
[This is an excerpt from the Centers for Disease Control and Prevention (CDC) guidance document on the use of respirators to prevent transmission of severe acute respiratory syndrome (SARS). For more information, see www.cdc.gov/ncidod/sars/respirators.htm.]
The CDC recommends the following guidelines on the use of respirators to prevent transmission of SARS:
- SARS, unlike tuberculosis, appears to spread by direct contact with respiratory secretions, which makes touching contaminated objects a potential concern. Although re-aerosolization of infectious material is unlikely under normal use conditions, infectious material deposited on a respirator may cause it to become a vehicle for direct or indirect transmission.
- Respirators should be used in the context of a complete respiratory protection program in accordance with Occupational Safety and Health Administration (OSHA) regulations. This includes training and fit testing to ensure a proper seal between the respirator’s sealing surface and the wearer’s face.
- Once worn in the presence of a SARS patient, the respirator should be considered potentially contaminated with infectious material, and touching the outside of the device should be avoided. Upon leaving the patient’s room, the disposable respirator should be removed and discarded, followed by hand hygiene.
- If a sufficient supply of respirators is not available, health care facilities may consider reuse as long as the device has not been obviously soiled or damaged (e.g., creased or torn). Data on reuse of respirators for SARS are not available. Reuse may increase the potential for contamination; however, this risk must be balanced against the need to fully provide respiratory protection for health care personnel.
- If N95 respirators are reused for contact with SARS patients (due to insufficient supply), implement a procedure for safer reuse to prevent contamination through contact with infectious droplets on the outside of the respirator. That may include wearing a loose-fitting barrier that does not interfere with fit or seal (such as a surgical mask or face shield) over the respirator.
- If respiratory protective devices with a filter efficiency of 95% or greater are not available, a surgical (procedure) mask should be worn. Surgical masks will provide barrier protection against large droplets that are considered to be the primary route of SARS transmission. However, surgical masks may not adequately protect against aerosol or airborne particles, primarily, because they allow for leakage around the mask and cannot be fit-tested. The mask should resist fluid penetration and fit tightly around the mouth and nose when properly applied to the face.
- Aerosol-inducing procedures should be performed on patients who may have SARS only when such procedures are deemed medically necessary. These procedures should be performed using airborne precautions as previously described for other infectious agents, such as Mycobacterium tuberculosis.