[M T]

ANOTHER variable to consider is mutations or gene sequences of the virus. What it was in December might not be what it is in March. Perhaps this would provide some clues to re-infection. Then again, testing may not have been able to pick up trace levels of the virus in people who had it but were cleared. IOW, re-infection could be a misnomer, and the reality is it never really went away.

Sometimes the more you think you know, the more you realize how little you do. Seems to be the case with SARS-CoV-2.

The WHO-China joint mission investigated mutations to Feb 24.

The Joint Mission carried out whole gene sequencing in 104 new coronavirus strains isolated from different locations
and confirmed that the homology among these strains reached 99.9%. Accordingly, the Joint Mission believes that the virus has no obvious variation

---

As for some people's belief that there must be a large set of asymptomatic people with the disease (same source as just above):

Some asymptomatic patients have been found. However, whether such cases are patients with asymptomatic infections or carriers whose virus is still  in  the  incubation  period  warrants  further study.  It  is  unclear  whether  the asymptomatic carriers can also spread the disease

From other accounts, the "some" appears to be 889 out of 72,000 (as of Feb 19).

A news article of Feb 15 says:

Zhang Hongxing, head of Wuhan's health commission, said last week the city tested about 6,000 to 8,000 people daily

That's at least 42K that week (counting Wuhan only).  The WHO-China Joint mission ended some 9 days later, which would suggest another 54K tested (in Wuhan).   That's far more than the 47,000 confirmed cases in Wuhan at that date (Feb 24).   If there were widespread asymptomatic cases, I would expect the number of confirmed cases would have climbed as that testing progressed, and the WHO-China joint mission would likely have noted that.  Instead, the opposite seems to be suggested by WHO  comment just above and by "the number of milder cases may not be great" I quoted in an earlier post.

From before, WHO's daily sitreps are here.
China's CDC daily sitreps are here. (not previously listed here)
US CDC page is here

[M T]

ANOTHER variable to consider is mutations or gene sequences of the virus. What it was in December might not be what it is in March. Perhaps this would provide some clues to re-infection. Then again, testing may not have been able to pick up trace levels of the virus in people who had it but were cleared. IOW, re-infection could be a misnomer, and the reality is it never really went away.

Sometimes the more you think you know, the more you realize how little you do. Seems to be the case with SARS-CoV-2.

The WHO-China joint mission investigated mutations to Feb 24.

The Joint Mission carried out whole gene sequencing in 104 new coronavirus strains isolated from different locations
and confirmed that the homology among these strains reached 99.9%. Accordingly, the Joint Mission believes that the virus has no obvious variation

---

As for some people's belief that there must be a large set of asymptomatic people with the disease (same source as just above):

Some asymptomatic patients have been found. However, whether such cases are patients with asymptomatic infections or carriers whose virus is still  in  the  incubation  period  warrants  further study.  It  is  unclear  whether  the asymptomatic carriers can also spread the disease

From other accounts, the "some" appears to be 889 out of 72,000 (as of Feb 19).

A news article of Feb 15 says:

Zhang Hongxing, head of Wuhan's health commission, said last week the city tested about 6,000 to 8,000 people daily

That's at least 42K that week (counting Wuhan only).  The WHO-China Joint mission ended some 9 days later, which would suggest another 54K tested (in Wuhan).   That's far more than the 47,000 confirmed cases in Wuhan at that date (Feb 24).   If there were widespread asymptomatic cases, I would expect the number of confirmed cases would have climbed as that testing progressed, and the WHO-China joint mission would likely have noted that.  Instead, the opposite seems to be suggested by WHO  comment just above and by "the number of milder cases may not be great" I quoted in an earlier post.

From before, WHO's daily sitreps are here.
China's CDC daily sitreps are here. (not previously listed here)
US CDC page is here