In new 'Kernel estimation', Chinese scientists conclude coronavirus first appeared in US
According to a report, Chinese scientists have concluded that the COVID-19 epidemic in the United States had a "high probability of beginning to spread around September 2019."
In a paper published by the Chinese scientists on the origin of the virus, it said the data was based on a "model hybrid driven method".
The scientists said as per "calculation results", the COVID-19 epidemic in China "has a high probability of beginning to spread in late December 2019."
The report said, "The calculation results show that the COVID-19 epidemic in the United States has a high probability of beginning to spread around September 2019."
"The date of the first case of COVID-19 with probability 50 per cent is inferred as December 20, 2019, and the date of the first case in Zhejiang is inferred as December 23, 2019," the report said.
The Chinese scientists said the "first infection" with a "probability rate of 50 per cent was mostly between August and October 2019" in the US, while adding that the earliest was on "April 26, 2019 for Rhode Island."
China had reported the first case of the virus to WHO on December 31, 2019. The US had reported the first case on January 20, 2020.
The report repeatedly mentioned Maryland where the US Army base Fort Detrick is located. China's foreign ministry had earlier alleged that the virus had spread from the research lab located in the facility.
The research said the "early detection" of the virus in the US was "obviously insufficient" while adding that "infected cases" were "seriously underestimated". The report cast doubts on the testing rates in the US.
The research was based on "Kernel density estimation" which it said can be applied to estimate the unknown probability distribution without prior knowledge.
It covered 13 US states including the district of Columbia. It included New Jersey, Vermont, New York, Rhode Island, Maryland, Michigan among others.
The researchers concluded that the virus spread in the US much earlier than in Wuhan.