A recent study suggests that Wuhan might have had coronavirus cases from August 2019. According to satellite imagery of car parking outside of major hospitals in Wuhan and search engine data, the study has been conducted.
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What does the Harvard study suggest?
The research was done by Harvard Medical School at Boston University of Public Health and Children’s Hospital in Boston. The researchers look at images captured between January 2018 to April 2020. The study suggests that there was an increasing number of vehicles around Wuhan hospitals from August 2019 and peaked in December 2019. From September to October, five out of six hospitals had the highest daily car volume. However, China’s foreign ministry called the study “extremely absurd” and rejected it.
The study also reported that along with the increasing number of vehicles, the rise in the number of people searching in Baidu search engine for “cough” and “diarrhea” also increased. The timespan was three weeks before coronavirus cases were reported of Wuhan and how the numbers were increasing in 2020. Researchers admitted that the queries of cough could coincide with the influenza season. However, symptoms of diarrhea are similar to COVID-19.
The researchers reported during a preprint that was published by Harvard’s DASH repository, that there was an increase in hospital traffic and search of symptoms online right before Sars-CoV-2 was announced a pandemic in December 2019. The published report said that August had an increase in searches for diarrhea, which was not as much as the flu season in the earlier times.
China’s response in defense
Hua Chunyign, a spokeswoman from China’s foreign ministry said that she hasn’t seen the study but rejects the conclusions. She said that it is extremely absurd to draw such conclusions based on superficial observations like search volume.
The origin of COVID-19 was first detected as a cluster of cases related to the Hunan seafood market during later December. Questions related to it has become very sensitive as China tries to defend themselves from accusations. However, they should be blamed for the pandemic that has killed more than 400,000 people. It has also crashed several economies across the world.
According to some scientists, the Harvard study has potential weaknesses. It is in pre-print and hasn’t gone through peer-review. A virologist professor from the University of Edinburgh, Paul Digard, said that using satellite imagery and search volume to detect an outbreak is interesting with little validity.
He said that if the study made a note of other Chinese hospitals having a similar surge in the number of hospital activity along with Wuhan, then it would have been more convincing. He added that data can be correlative but cannot ensure accuracy. By focusing on the healthcare sector of the epicenter of coronavirus, the report forces the correlation. However, it would have been interesting to see the same analysis on other Chinese cities outside of the Hubei region.
Reviews regarding the study
An Emeritus Professor of the epidemiology who is trained for infectious diseases, and working in the University of Nottingham, said that two of the hospitals kept under check were Children’s Hospital of Wuhan. It is described to be the biggest pediatric hospital in Hubei. However, few children have been hospitalized due to COVID-19. He said that this explains that their admission was not coronavirus.
The authors who conducted the study admitted that they cannot confirm if the number of vehicles increased due to coronavirus. Wuhan entered the influenza season at that time and many doctors said that schools were canceled due to flu.
High regulations satellite imagery could not be extracted due to tall buildings, smog, and trees. Also, there was limited archival footage of Wuhan in the previous years as it was low on commercial interest.
Evidence show that the emergence of the virus was before the identification of the Huanan wet market. The finding confirms that the virus naturally emerged from southern China. Further, it was circulating during the time of outbreak in Wuhan.