Swiss Cheese Infographic - How to prevent Covid transmission

The Swiss Cheese Model applied to Covid-19

Professor James T Reason proposed a layered approach to reducing the risk of accidents due to human error for transmission of Covid.

I really liked this approach for communicating risk reduction. Adapting it creates a simple way to get across that no single intervention (layer) is perfect, Each layer has its failings (holes) that can come and go and be made worse. Using lots of layers provides a better chance of preventing transmission of SARS-CoV-2, the virus that causes COVID-19. You can read the entire article here.  In the article, Professor Reason discusses "Holy Thinking" (see below) and how each layer of defense can have its problems.  If all the holes line up, transmission can happen. 

Excerpt from the article......

"Holy thinking"

Where do these holes come from? Let’s look at masks. We know they are good for preventing the wearer from spreading their virus-laden aerosols to others and into the air. They also serve some role in preventing a wearer from inhaling those aerosols. So what causes holes in this imperfect layer of risk reduction? Here are some ideas…

  • The mask is not worn properly (under the nose, on the chin, too loose)
  • Not disposing of the mask properly, putting others at risk of handling it
  • Not sanitising your hands after handling the mask
  • Fiddling with the outside of the mask while wearing it without sanitising your hands before touching your face or someone else
  • Not cleaning your mask properly or often enough
  • Sharing masks
  • Not using the right type of fabric or enough layers for your mask
  • Overconfidence that wearing a mask will be highly protective and thus engaging in risky behaviours as a result of that confidence

And those are just some of the holes in one layer!