This article is aimed primarily at nurses, health care workers, and policy managers everywhere.
My husband is a nurse and, as a veterinarian, I have some training in epidemiology and virology. I have been following the situation since mid-February.
There is a lot of information out there and discerning good sources can be difficult. I have been frustrated with the information found at the CDC and WHO. I felt like droplet and fomite spread might not be the only modes of transmission for this virus, i.e. that just washing our hands well might not be enough. Turns out the science is beginning to support that.
Recently I found a site I like much better for up to date news on the COVID outbreak: the Center for Infectious Disease Research and Policy’s ‘News and Perspective’ site. I highly recommend this site. It gives unbiased, non-partisan information for the US and the World. I now am limiting my COVID new consumption to this site and the John’s Hopkins reals time COVID map (links at bottom).
It promotes basing our responses on science (of course, I would like that!)
Here are some excerpts from articles at this excellent site. Again – this is for nurses, healthcare workers, managers, and policymakers. Basically, it explains why we should be covering our healthcare personnel for aerosolized virus spread. If you want more then my hand-selected excerpts, please go read the whole article.
An often ignored, yet important mode of transmission for infectious respiratory diseases—close-range aerosol transmission—needs to be part of the equation….
The CDC admits some possibility that COVID-19 may be transferred by hands to mouth, nose, or eyes from contaminated surfaces, but notes that “this is not thought to be the main way the virus spreads.”11
the WHO states, “COVID-19 appears to spread most easily through close contact with an infected person. When someone who has COVID-19 coughs or sneezes, small droplets are released and, if you are too close, you can breathe in the virus”
Underlying the CDC and WHO statements about transmission is this: Inhalation of particles near the source may be an important mode of transmission.
The precautionary principle suggests we should approach this organism as we would any novel highly transmissible respiratory disease—as a contact, droplet and airborne disease, but with one important caveat: Short-range aerosol transmission is also a strong possibility….. the precautionary approach suggests that we focus on preventing short-range aerosol transmission in both public and healthcare settings.
For aerosol-generating procedures, the CDC should be recommending respirators with higher levels of protection than an N95 filtering facepiece respirator (eg, a powered air-purifying respirator), but at this point, it does not. In the face of supply shortages, the CDC last week changed its recommendations to allow the use of medical masks instead of respirators, saving the latter for aerosol-generating procedures.1 Healthcare organizations must return to using respirators for confirmed and suspected COVID-19 patients when supply chain problems are resolved. Requirements for airborne infection isolation rooms remain in place.
Organizations are encouraged to designate entire units for COVID-19 patient care and develop re-use procedures for personal protective equipment.
…. Healthcare organizations and public health agencies should consider the utility of reusable respirators, such as elastomeric respirators more commonly found in industrial settings. Such respirators may be in limited supply, but they offer some advantages, in that healthcare employees can be given an individual respirator for which they are responsible.
Healthcare organizations should also be considering source controls, such as cohorting suspected and confirmed patients, limiting the number of healthcare workers involved in care, using telemedicine, designating separate locations for triage and care, and deploying remote technologies, where possible.
Contrary to popular belief, the larger particles (5 to 15 micrometers [µm]) will not immediately drop to the ground but will remain airborne for several minutes. Smaller particles (less than 5 µm) will remain in the air for many minutes or even hours.
All particles will immediately begin to evaporate (mucus contains a lot of water), which means the range of particle sizes will decrease overall. Smaller particles are more affected by diffusion than gravity, thus making them more likely to remain airborne. In the absence of air currents, airborne particles will disperse slowly throughout a space (see the figures below).
China deployed a tiered hospital model very similar to that used for Ebola patients in the United States.21 Patients with critical or severe symptoms were moved into designated wards or hospitals while those with mild symptoms were cohorted in temporary hospitals in repurposed buildings. Healthcare workers wore full protection, including a gown, head-covering, N95 filtering facepiece respirators, eye protection, and gloves.22
…Different genotypes found in a paired throat swab and sputum sample from one patient suggest that replication may occur in the throat independently from the lung.
…The authors conclude that SARS-CoV-2 may be more efficient at transmitting than SARS-CoV through active shedding from the upper respiratory tract as symptoms are developing. Later on, COVID-19 is more like SARS, with replication in the lower respiratory tract. They conclude: “Our initial results suggest that measures to contain viral spread should aim at droplet-, rather than fomite-based transmission.” (ref Woelfel et al, 2020).
… The effectiveness of hand hygiene in community settings is minimal.38
….In a temporary Wuhan hospital fashioned from an indoor sports stadium for cohorting and treating patients with mild symptoms, high RNA concentrations were found in rooms used for removal of protective clothing (18 to 42 copies/m3), with the highest concentrations found in 0.25- to 0.5-µm particles, thought to result from particle release from contaminated clothing.
High RNA concentrations (19 copies/m3) were measured in patient toilets in both hospitals. Toilet flushing is well-known as a source of aerosols.25
….A very recent study found that SARS-CoV-2 aerosols remain viable for up to 3 hours,32, which is similar to the viability of SARS-CoV in air33 and MERS-CoV.34,35 This is adequate time for exposure, inhalation, and infection to occur both near and far from a source.
… More than half of those contracting SARS during the 2003 pandemic were healthcare workers. As of early February 2020, more than 3,000 healthcare workers were believed to have contracted COVID-19 in China, and at least 6 died.37
Excerpted by Dr. Tama Cathers
JOHN HOPKINS MAP