CDC Draft Revamps Airborne Precautions, Calls for N95s

November 10th, 2023

By Gary Evans, Medical Writer

New draft patient isolation guidelines recently approved by advisors to the Centers for Disease Control and Prevention (CDC) call for scrapping the old droplet-airborne approach in favor of three tiers of air transmission precautions, two of which call for the use of N95 respirators.

“The draft 2024 guideline updates the conceptual framework for pathogen transmission, including the recognition of a continuum of pathogen transmission by air rather than an outdated dichotomy of droplet vs. airborne transmission,” said Michael Lin, MD, MPH, head of the isolation workgroup for the CDC’s Healthcare Infection Control Advisory Committee (HICPAC). “It proposes new categories for transmission-based precautions.”

The draft guidelines now go to the CDC for review, and, if approved, they will be published in the Federal Register for a two-month comment period. They will then be brought back for finalization by HICPAC. The move is the result of both widespread criticism and attendant research that showed COVID-19 could be transmitted through the air, in some cases well beyond the six-foot masking requirement for droplet precautions.

The new approach to airborne pathogens includes these three distinct tiers.

Routine Air Precautions:

“Routine Air Precautions are focused on reducing transmission of common, often endemic, respiratory pathogens that spread predominantly over short distances based on observed patterns of transmission, and for which individuals and their communities are likely to have some degree of immunity,” the draft guidelines state.

• Healthcare Personnel (HCP) should use a mask on room entry and use eye protection based on Standard Precautions.
• Place patient in a private room; if not available, then cohort.
• Rooms should be appropriately ventilated, but an Airborne Infection Isolation Room (AIIR) is not routinely needed.
• Source control masking should be used by the patient when they leave their room (e.g., for transport to a procedure).

Special Air Precautions:

"Special Air Precautions are applied to patients with a respiratory pathogen, typically new or emerging, that is not observed or anticipated to spread efficiently over long distances (such as through ventilation systems), for which infection generally leads to more than mild illness, and where immunity (or vaccine) and effective treatment are not available," the guidelines state.

• HCP should use a NIOSH-approved fit-tested N95 (or higher-level) respirator and eye protection on room entry.
• Place patient in a private room. If not available, then cohort.
• Rooms should be appropriately ventilated, but an AIIR is not routinely needed.
• Source control masking is indicated for the patient when they leave their room (e.g., for transport to a procedure).

Extended Air Precautions:

"Extended Air Precautions are used when providing care to patients with pathogens that are observed to spread efficiently across long distances and over extended times, such that room air needs to be contained (e.g., prevented from moving into the hallway where individuals are not appropriately protected)," the guidelines state.

• A NIOSH-approved fit-tested N95 (or higher-level) respirator is worn by HCP on room entry, and eye protection is used based on Standard precautions.
• A private room is indicated.
• An AIIR is required.
• Source control masking is indicated for the patient when they leave their room.
• Travel outside the room should be limited (e.g., for necessary procedures and treatments).

For more on this story, see the next issue of Hospital Infection Control & Prevention.

Gary Evans, BA, MA, has written numerous articles on infectious disease threats to both patients and healthcare workers for more than three decades. He has been honored for excellence in analytical reporting five times by the National Press Club in Washington, DC.