Washington (AFP)

A leap in internet research into the symptoms of Covid-19 and the surge in hospitals in the Chinese city of Wuhan suggests that the disease may have appeared there as early as August 2019, according to the results of a preliminary American study.

The coronavirus, which comes from a virus that can be transmitted from animals to humans, was first identified in the Huanan market in Wuhan, China, where exotic animals were sold live, in December 2019.

Experts then determined that an earlier genetic version of the virus had emerged in mid-November 2019. An article in the Hong Kong daily South China Morning Post reported that a "zero patient" was found on November 17 citing data government.

The new study, which has not yet appeared in a publication of the scientific community, was carried out through the prism of a still recent discipline, "digital epidemiology".

A team led by Elaine Nsoesie of Boston University analyzed 111 satellite images of Wuhan over a period from January 2018 to April 2020.

"A sharp increase in traffic from August 2019" was detected in the parking lots of Wuhan hospitals, "culminating in a peak in December 2019," noted the authors of the research.

Scientists have also been monitoring the most typed symptoms on the Chinese search engine Baidu.

Study members saw a jump in searches for the word "cough", which may correspond to seasonal flu, but also in searches for the word "diarrhea", which is a more specific symptom of Covid-19.

"In August, we noted a significant increase in research related to diarrhea, which had never been seen in previous seasonal influenza or which was not reflected in the cough research data," said the scientists. .

If the most well-known symptoms of the coronavirus are respiratory, the study suggests that diarrhea "could play an important role in community transmission" of the disease.

The authors concluded that if they were unable to make a definitive statement that the data identified were related to Covid-19, the study supported the results of other research on the subject.

"These results also support the hypothesis that the virus appeared naturally in southern China and that it was potentially already circulating at the time of the Wuhan outbreak," they wrote.

© 2020 AFP