Harvard Medical School researchers propose that COVID-19 may have surfaced in China earlier than previously thought, potentially as far back as the summer of 2019. This preprint analysis draws on satellite imagery and search data.
In May 2020, British scientists analyzed 7,000 SARS-CoV-2 genome sequences, tracing patient zero to Wuhan between October 6 and December 11, 2019. They identified the most recent common ancestor (MRCA) amid mutations and evolutionary changes.
A June 2020 preprint report (PDF in English / 10 pages) from Harvard Medical School suggests the virus emerged as early as August 2019, no later than early fall. Satellite images reveal Wuhan hospital parking lots filling noticeably from August, peaking in December. Baidu searches for "cough" and "diarrhea" also surged during this period.
Officially, COVID-19 was first reported at a Wuhan market in December 2019, with China notifying the UN on December 31. This Harvard analysis notes an upward trend in hospital traffic and search volumes months earlier, suggesting the virus had reached southern China and possibly spread internationally. It may have already strongly adapted to humans by December.
The report challenges market origin theories, as 14 of the first detected cases had no direct link to it.
This work is a preprint shared via Harvard's Digital Access to Scholarship, not yet peer-reviewed in a journal. Further validation is needed.
