Loss of taste or smell is one of the strongest signals for COVID-19. Though not every COVID-19 case has this symptom, it's a very specific symptom that doesn't commonly have other causes. This question is about the suitability of coffee beans as a low cost testing tool for COVID-19. I'm interested in exploring this as I lead development of the WHO COVID-19 app.
The Odds Ratio for a person reporting loss of taste or smell was reported as 6.7 through the COVID Symptom Study in their Nature research paper: Real-time tracking of self-reported symptoms to predict potential COVID-19. Overall AUC reported as 0.75 for all user symptoms. It's not accurate enough to be a diagnosis but it can be combined with other symptoms, cough recording and COVID exposure information to improve accuracy to do screening for further tests. The question is whether adding a specific daily smell test using coffee beans would be worthwhile?
The general thought is to have a cup of coffee beans that you smell on a daily basis. Then report in the app if you had a loss of smell. The ideal test is fast, cheap and easy. To be fast, the container may need to be open so you don't have the daily irritation of having to remove a sealed lid. I considered a coffee bean as I thought they'd be cheap and available around the world.
If you'll excuse multiple questions, I have some specific areas I was looking for feedback on....
How to get consistency in smell? Smell decay curve for coffee beans. How quickly does open coffee beans lose their smell? How does an open / closed container impact this? How often might you need to replace the beans due to smell decay, mold or other reasons?
Cost of coffee beans. How widely available and affordable are they in some of the poorest communities in the world?
Any other product that you think that could be more effective. It needs to be an existing widely available low cost product.
Please share any other thoughts or feedback you might have.