Public health experts are voicing concern over the potential risks introduced by the World Health Organization’s (WHO) updated guidelines for COVID-19 prevention and control, targeting healthcare workers, patients, and the community. According to Lisa Brosseau, ScD, CIH, an infectious diseases and respiratory protection specialist, these guidelines fail to acknowledge proven mechanisms of viral dissemination and therefore put all involved parties at an increased risk of infection.
Moreover, Raina Macintyre, MBBS, PhD, a biosecurity program leader in Sydney, clarifies that the new document neglects key insights garnered from the pandemic’s unfolding, notably the significant aspect of asymptomatic spread of COVID-19. This understanding should have endorsed universal masking in high-transmission settings, regardless of symptom presence, she argued.
Another critique from David Michaels, PhD, MPH, an epidemiologist, is that the guidelines bypass a discussion on the modes of COVID-19 spread. This misalignment propels the false assumption that SARS-CoV-2 is predominantly transmitted through droplets rather than aerosols, an idea he terms the ‘droplet dogma.’ Such a misguided perspective overlooks the superior protection offered by N95 respirators compared to typical medical masks, he argued.
Despite these concerns, the guidelines justify the interchangeability of different types of masks except in specific conditions. Yet, it is widely known that medical masks demonstrate subpar filtration capabilities for smaller particles and exhibit considerable leakage around the facepiece. Therefore, although such masks can control the source of larger droplets due to coughing and sneezing, they prove insufficient for airborne viruses like the coronavirus, underscoring the need for better protection measures in healthcare settings.
Further to this, critics pointed out that the suggested use of physical barriers like Plexiglass screens could even be detrimental by impeding airflow. Not to mention, the one-meter physical distancing recommendation lacks an evidence-based rationale.
Another point of contention is the dichotomy of ‘targeted continuous’ use of masks, seen as a problematic new terminology, and the WHO’s ‘low certainty’ status on key procedures involving airborne pathogens such as ventilation, despite a dearth of evidence for other practices deemed as ‘good practice.’
The guidelines also raise questions in terms of fit-testing. While medical masks, not necessarily designed for preventing small particle escape, are recommended to have improved fits, the utility of fit-testing for superior performance respirators is dismissed.
Brosseau, Michaels, and Macintyre all endorse universal respirator usage in healthcare settings, especially during increased transmission periods. Current protective measures ignore the fact that virus-containing aerosols can fill indoor environments for extended periods, emphasizing the need for universal, ongoing respiratory protection for healthcare workers.
The medical community, patients, and visitors should be prompted to use respirators where feasible, particularly during periods of high respiratory virus circulation. From the lessons of the pandemic, it is crucial to balance comfort, accessibility, and efficacy to prevent illness and reduce the overall burden of viral diseases.