SHANGHAI (Reuters) – The number of people infected with COVID-19 in the Chinese city of Wuhan, where the virus was first identified, could be about three times higher than the official figure, according to a study by Chinese researchers headquarters in the city.
The paper, published on Thursday by PLOS Neglected Tropical Diseases, analyzed blood samples from more than 60,000 healthy people taken from locations in China from March to May 2020.
It found that 1.68% of those in Wuhan contain antibodies to SARS-CoV-2, the virus that causes COVID-19, compared to 0.59% in the surrounding Hubei Province and 0.38% in the rest of China.
With a total city population of over 10 million, researchers estimated that up to 168,000 Wuhan residents were infected with the virus, compared to the official number of 50,340 hospitalized cases.
The study suggested that at least two-thirds of the total number were asymptomatic and thousands could have been infected after “elimination” of clinical cases, increasing the possibility that the virus would exist in a community for a long time without causing hospitalizations.
A separate study published by the Chinese Center for Disease Control and Prevention (CDC) late last month found the rate of “seroprevalence” in Wuhan, the percentage of the population with antibodies, even higher at 4.43%, implying that about half of million people in the city could have been infected.
COVID-19 was identified in Wuhan at the end of 2019, the first outbreak being associated with a seafood market in the city. China eventually closed Wuhan and other cities in Hubei Province on January 23, 2020, but critics say it should have acted faster.
China has rejected criticism of early handling of the virus, and officials are now pointing to overseas studies suggesting it was circulating in Europe a few months before the outbreak in Wuhan.
A team of 10 members of the World Health Organization was due to arrive in China this week to investigate the origins of COVID-19, but they have not yet received permission to enter the country.
The total number of confirmed cases of COVID-19 so far in mainland China now stands at 87,331, while the death toll has remained unchanged at 4,634.
Reporting by David Stanway; Edited by Michael Perry