(BBC) – An apparent surge in traffic outside Wuhan hospitals from August 2019 may suggest the coronavirus hit the area earlier than reported, a study says.
Harvard researchers say satellite images show an increase in traffic outside five hospitals in the Chinese city from late August to December.
The traffic spike coincided with a rise in online searches for information on symptoms like “cough” and “diarrhoea”.
China said the study was “ridiculous” and based on “superficial” information.
It is believed that the virus first appeared in China some time in November. Authorities reported a cluster of pneumonia cases with an unknown cause to the World Health Organization (WHO) on 31 December 2019.
“Clearly, there was some level of social disruption taking place well before what was previously identified as the start of the novel coronavirus pandemic,” Dr John Brownstein, who led the research, told ABC news.
The study has not been peer-reviewed.
What did the study show?
The researchers examined commercial satellite data from outside five Wuhan hospitals, comparing data from late summer and autumn 2018 to the same time period in 2019.
In one case, researchers counted 171 cars parked at one of Wuhan’s largest hospitals, Tianyou Hospital in October 2018.
Satellite data from the same time in 2019 showed 285 vehicles in the same place, an increase of 67%.
A surge in online searches for words associated with the symptoms of coronavirus on the Chinese search engine Baidu seemed to emerge at the same time.
“This is all about a growing body of information pointing to something taking place in Wuhan at the time,” Dr Brownstein told ABC.