American researchers suggested that the coronavirus COVID-19 could spread in China in the summer of 2019 – several months earlier than it was officially announced.
Scientists at Harvard Medical School, Boston University and the Children’s Hospital in Boston in the United States studied satellite images of parking lots at hospitals in China, as well as Chinese searches in the Baidu system. As a result, the researchers found that in the late summer and early fall of 2019, the number of cars in hospitals in Wuhan sharply increased, and coughing and diarrhea, which are some of the symptoms of COVID-19, often came across in search queries.
Scientists believe that SARS-CoV-2 could already circulate among the population before it was detected on the Huanan market. This hypothesis is supported by emerging epidemiological and phylogenetic evidence that are indicating that the virus appeared in southern China and could already spread to other countries and adapt to effective transmission between people by the time it is detected in late December.
Scientists also added that they cannot confirm the relationship between the increase in search queries and the number of vehicles in parking lots.