A preliminary study conducted by researchers at Boston and Harvard universities showed that a significant increase in the proportion of hospital visits and Internet searches related to symptoms of Covid-19 from Wuhan, China, may indicate that the emerging corona virus may have spread since August 2019.
The epidemic, which was linked to a virus transmitted from animals to humans, was initially detected at the Huanan Seafood Market in Wuhan in December 2019.
Later, experts spoke of a genetic predecessor to the virus in mid-November 2019.
A report in the "South China Morning Post," quoting government data, indicated that the first patient or "patient zero" could return to November 17.
This new research, which has not yet been published in a scientific journal, comes under the relatively new field of "digital epidemiology".
A team led by Eileen Nesusi at Boston University analyzed 111 satellite images of Wuhan between January 2018 and April 2020, and discovered that many searches for symptoms similar to Covid-19 symptoms were performed on the Chinese search engine Baidu.
The authors of the study wrote, "There has been a significant increase in the number of parked cars in the garage of Wuhan Hospital, starting in August 2019" and peaking in December 2019.
Because inquiries about the word "cough" rise in the annual flu seasons, search has also been made for "causes of diarrhea" which is one of the most specific symptoms of Covid-19.
"In August, we identified a significant increase in searches for diarrhea that did not appear in previous flu seasons or were reflected in research data on coughs," the team said.
While respiratory symptoms are the most common feature of SARS-Cove-2 infection, the study suggests that diarrhea “may play an important role in the local transmission of the virus.”
The authors said they were unable to conclusively confirm that the data they documented was related to the virus, but that their research supported the conclusions of other research.