CDC HICPAC Considers New Airborne Pathogen Guidelines Amid Growing Concerns

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This month’s CDC HICPAC (Healthcare Infection Control Practices Advisory Committee) meeting focused on answering questions posed by CMS. The answers will serve as a guide for revising recommendations regarding controlling the spread of airborne pathogens.

One of the questions dealt with the definition of “severe illness,” which has been a prevention goal of COVID-19 interventions. “Severe Illness” was redefined as not just the prevention of “hospitalizations and deaths” but the prevention of “morbidity and mortality and other adverse outcomes.”This would include the disabling effects of long COVID and was a welcome change.

The question regarding whether source control (masking) should always be used in facilities had only one supporting vote. This was surprising because health care facilities are where sick patients congregate. Facilities will, thus, have higher rates of spread than found in communities. Not having a policy of universal masking poses a definite risk to immunocompromised patients and a possible violation of the ADA. In many indoor settings, including infusion centers, which are crowded with patients and visitors, universal masking does not occur. 

Despite the persistence of SARS-CoV-2 and a looming H5N1 epidemic, most of the Committee, except for one member, appeared to want to maintain a status quo in our approach to airborne illnesses. The committee consensus was that N95 masks had not been conclusively shown to be more effective than masks or surgical masks in all clinical settings.
 
Source control was also discussed. However, the option that appeared to have HICPAC support was to only recommend the use of N95 masks some of the time, depending upon the pathogen; otherwise, surgical masks were advised. This made little sense since surgical masks do not adequately protect against pathogens that can spread through the air. By the time you can evaluate a patient to determine what type of pathogen the patient has, it may be too late to block transmission to the health care worker.

Even if the patient just has a cold, why should the worker be exposed to an illness that would necessitate several days off of work, or if paid sick leave was not available, going to work and placing immunocompromised patients at risk? I would have recommended universal N95 masks, as outlined below in strategy “Narrative B.” (See Table)

Table: Framework for Alternate Narrative B

(See disclaimer from CDC)

Even a clear statement that health care workers can voluntarily wear their own N95 masks failed with a 6 to 5 vote. The committee opted to follow another Federal Agency's policy that places voluntary use at the employer's discretion. If a worker was immunocompromised or had an at-risk relative at home, one might only be willing to work in health care if allowed to wear an N95 mask. In health care, unlike many other work settings, a worker never knows when one will be exposed to a dangerous airborne occupational hazard. For some, the committee’s decision appeared to be about whether a facility’s administration or a front-line nurse will decide if the treating health care provider can wear an N95 mask. Ironically, in January 2022, the CDC updated its mask guidance to allow the public to choose to wear an N95 mask.
 
Surgical masks are intended to protect the patient from droplets and spit produced by a surgeon. They have some effectiveness regarding source control but will not provide the wearer with adequate protection. Some committee members justified their decision by stating N95 masks were too burdensome to be uniformly used and that health care facilities must also focus on other major problems they face, such as health care staffing shortages and health care violence.
 

Members of HICPAC

(Screenshot credit to author)

However, COVID-19 and long COVID are a major cause of workforce shortages. In the United Kingdom, recent research has found a third of health care workers have symptoms of long COVID. In addition, the psychological stresses of the pandemic, along with viral damage of the frontal and prefrontal cortex, may well be a significant driver of the violence we are seeing in schools, hospitals, traffic accidents, and our society as a whole.
 
The health care workforce can be exposed to sizeable biological dosages of airborne pathogens for extended periods. In this setting, research trials on masking may not always detect differences between surgical and N95 masks since exposure dosages may be far too high. Any break in the protocol of wearing an N95 mask can result in an infection. In addition, a worker can be infected through their eyes.

N95 masks are currently widely available, but availability may drop as manufacturers cut back or curtail protection due to decreased demand. This may leave us exposed when we are hit with our next pandemic. H5N1 is a looming threat that we need to be prepared for. Thus, one could argue that a facility should maintain a 6-month supply of respirators at pandemic usage levels and draw from this supply for staff personal protective equipment (PPE) usage.
 
One must ask, will workers have adequate protection? The answer is that masks alone do not afford optimal protection in health care settings; a layered approach is needed emphasizing optimal-safe ventilation. More facilities need to follow ASHRAE 241 standards. Remember, dosage and exposure time determine your chances of infection.

Our current approach to reducing the spread of airborne pathogens must focus on reducing viral dosage. Strong evidence supports that N95 masks will reduce dosage exposure far better than surgical masks. However, this reduction may not prevent infection in all clinical settings. Instead of NOT recommending N95 masks, we must add additional layers to reduce exposure dosage. These layers include maximizing ventilation, testing, and source control. All are needed to maintain patient safety and a healthy health care workforce.