‘Coronavirus has been spreading in China since last August’: Reveals study using satellite images

A study has revealed that the coronavirus has been spreading and circulating in China from August 2019. The study led by researchers from the Harvard Medical School, Boston University of Public Health and Boston children’s hospital  has revealed this. The research team has used satellite imagery of parking lots and disease-related search engine queries for  finding this.

The research team reveals that   they observed an upward trend in hospital traffic and search volume for disease-related terms beginning in late summer and early fall of 2019, implying that the virus may have already been circulating before the identification of the Huanan market cluster in Wuhan late November, early December.

“This hypothesis is supported by emerging epidemiologic and phylogenetic evidence indicating that the virus emerged in southern China and may have already spread internationally, and adapted for efficient human transmission by the time it was detected in late December,” the study says.

For the study, researchers collected over 111 satellite images of Wuhan from January 9, 2018 to April 30, 2020 resulting in 140 successful daily extractions of parking lot volume from hospitals. As per their analysis, between 2018 and 2020 there was a general upward trend of increased hospital occupancy and a “steep increase” in volume starting August 2019. Further, while individual hospitals have days of high relative volume in both Fall and Winter 2019, between September and October 2019, five of the six hospitals show their highest relative daily volume, which coincides with elevated search queries for the term “diarrhea” and “cough”.

Searches for “diarrhea” showed elevated traffic starting in late 2019, “cough” shows yearly peaks that coincide with the influenza season. Both the search terms show a large increase approximately three weeks preceding the large spike in confirmed COVID-19 cases in early 2020. The researchers observed a “large decrease” in hospital volume and search query data following the public health lockdown of Wuhan on January 23, 2020.