[M T]

In retrospect, I believe we were seeing Covid-19 at work throughout January. A bunch of kids were coming in who appeared to have influenza but they had negative influenza nasal swabs. They all had prominent hacking coughs, fevers and headaches. We'll see if the Stanford Covid antibody testing confirms that.

The standard response would be, if they had Covid-19, where were the pneumonia cases (not necessarily in the kids, but in the parents or grandparents or teachers)?   But you know that question, so you must have thought about it already.   So, where were they?   The CT scan of the pneumonia is, I believe, very distinctive and should have been obvious in January, and certainly obvious in retrospect.   And, also, why didn't you or the staff around you get it?

We see in country after country that about 20% of those that test positive for COVID-19 get pneumonia about 5 days after symptom onset.

Is it possible there are two diseases running around, both new & both producing similar coughs?  It seems extraordinarily unlikely to me, but could be.  One is capable of giving you the COVID pneumonia, and the other not.   There could even be some antibody effect, like cowpox and small pox.  The question would be, why hasn't it been sequenced and detected as different?  Have all the sequences been from the severe cases?

I have been wondering why only ~10% of the tests have been positive for COVID-19.   A year ago, one might have thought that the 90% were flus or colds.  But with social distancing in full force, and the evidence of flu seemingly low, it feels unlikely that these are the flu or colds.   Could they all be like your situation (an allergy cough in a health worker) where a test was required?  With the scarcity of COVID-19 testing, I had thought all the sick would first be given the standard set of tests (flu, etc.).

If there were two diseases, then it would almost seem likely that some of those with the severe cases would have both kinds, and it would be found in them.

If there are two diseases, then the question would be if the non-COVID disease may confer any immunity to the COVID disease. 

The epidemiologists have indicated that the pattern of spread in China and elsewhere indicates a significant number of asymptomatic cases.  I don't think those models would be influenced by a different disease with similar symptoms.  (I believe the models require they asymptomatic cases to spread the COVID-19 and cause symptomatic cases to appear.)

I presume there's no way to go back and test the January swabs for COVID-19.

[M T]

In retrospect, I believe we were seeing Covid-19 at work throughout January. A bunch of kids were coming in who appeared to have influenza but they had negative influenza nasal swabs. They all had prominent hacking coughs, fevers and headaches. We'll see if the Stanford Covid antibody testing confirms that.

The standard response would be, if they had Covid-19, where were the pneumonia cases (not necessarily in the kids, but in the parents or grandparents or teachers)?   But you know that question, so you must have thought about it already.   So, where were they?   The CT scan of the pneumonia is, I believe, very distinctive and should have been obvious in January, and certainly obvious in retrospect.   And, also, why didn't you or the staff around you get it?

We see in country after country that about 20% of those that test positive for COVID-19 get pneumonia about 5 days after symptom onset.

Is it possible there are two diseases running around, both new & both producing similar coughs?  It seems extraordinarily unlikely to me, but could be.  One is capable of giving you the COVID pneumonia, and the other not.   There could even be some antibody effect, like cowpox and small pox.  The question would be, why hasn't it been sequenced and detected as different?  Have all the sequences been from the severe cases?

I have been wondering why only ~10% of the tests have been positive for COVID-19.   A year ago, one might have thought that the 90% were flus or colds.  But with social distancing in full force, and the evidence of flu seemingly low, it feels unlikely that these are the flu or colds.   Could they all be like your situation (an allergy cough in a health worker) where a test was required?  With the scarcity of COVID-19 testing, I had thought all the sick would first be given the standard set of tests (flu, etc.).

If there were two diseases, then it would almost seem likely that some of those with the severe cases would have both kinds, and it would be found in them.

If there are two diseases, then the question would be if the non-COVID disease may confer any immunity to the COVID disease. 

The epidemiologists have indicated that the pattern of spread in China and elsewhere indicates a significant number of asymptomatic cases.  I don't think those models would be influenced by a different disease with similar symptoms.  (I believe the models require they asymptomatic cases to spread the COVID-19 and cause symptomatic cases to appear.)

I presume there's no way to go back and test the January swabs for COVID-19.