Sunday, March 1, 2020

Infection prevention

At this time, it appears that COVID-19 can spread by droplet, aerosol, fomites (objects) and through intestinal secretions.

The incubation period, it seems, may be up to 14 days.  Or much longer.  People who recover may still be able to spread virus--this is unclear (it depends on their viral load) but adds another problem to the attempt to contain the virus.

I am of the impression the virus cannot be contained.  Now that CDC and FDA will permit new tests to be used (as of late 2/28) and will stop restricting testing to those with a very strong China connection and compatible disease symptoms, we should get a better idea about asymptomatic cases and the period during which cases are contagious.

CDC has still failed to commit itself to precisely what disinfectants can be used to effectively decontaminate objects/surfaces. 

https://www.cdc.gov/coronavirus/2019-ncov/infection-control/control-recommendations.html

CDC evades the issue by recommending EPA-approved products. Then CDC provides a link to a page designed for manufacturers to help get their products approved by EPA.

https://www.epa.gov/pesticide-registration/guidance-registrants-process-making-claims-against-emerging-viral-pathogens

The information on decontamintion that is available is general, lacking the benefit of testing against COVID-19.

https://www.cdc.gov/hai/pdfs/resource-limited/environmental-cleaning-508.pdf#page30

This is unforgiveable.  For SARS, virus testing revealed the potential for virus to remain viable longer than a week under some environmental conditions. 

The main thing we can do is to know exactly where our hands are all the time and keep them away from all our mucus membranes.  I suggest people start to practice this.  Wash hands frequently with soap and water (proven to work) and use moisturizers as needed to avoid getting cracks in your hands.  Work from home if you can.

Consider using a plastic barrier (like the bags supplied by grocery stores for fruits and veggies-- for most of us who don't have an infinite supply of gloves) when touching surfaces used by others.

I think the WHO's recommendations are quite reasonable.  Except that 3 feet distance away from someone coughing/sneezing is not sufficient to avoid smaller droplets; CDC now says stay 6 feet away, and even that may not be enough for a powerful expulsion of virus.

https://www.who.int/docs/default-source/coronaviruse/getting-workplace-ready-for-covid-19.pdf

Meryl Nass, MD

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