The study used a sample of 34,000 people from the general population of Wuhan, the original epicenter of the pandemic, and other cities in Hubei Province, as well as Beijing, Shanghai and Guangdong Provinces, Jiangsu, Sichuan and Liaoning. estimates Covid-19 infection rates.
The study aimed to estimate the scale of past infections in a population by testing blood serum samples from a group of people to detect antibodies against coronavirus. Their findings are not considered final statistics of how many people in a given area have been exposed to the virus.
The Chinese CDC said the study was conducted a month after China “contained the first wave of the Covid-19 epidemic.” The prevalence rate outside Wuhan is significantly lower, according to the study. In other cities in Hubei, only 0.44% of the respondents were found to have antibodies against coronavirus.
Outside the province, antibodies were only detected in two people among the more than 12,000 residents surveyed.
Unreported coronavirus infections
Yanzhong Huang, a senior global health member of the Foreign Relations Council, said the study points to an underinformation problem of infections during the height of the outbreak in Wuhan, in part due to the chaos of the time lack of asymptomatic inclusion of cases in the official count of confirmed cases.
Underinformation is a problem facing health authorities in many countries, often due to lack of capacity and resources. Antibody studies by researchers in other parts of the world also show that coronavirus was much more prevalent than official figures suggest.
But in China there is also the issue of transparency, as officials gave the public more optimistic data than they had access to internally.
Effective containment in Wuhan
The study reveals a huge contrast between the prevalence rates of coronavirus antibodies inside and outside Wuhan.
Huang said significantly lower rates in other Chinese cities suggest that “Chinese containment efforts were quick and effective, especially compared to cities like New York.”
In an unprecedented bid to contain the rapidly spreading virus, Wuhan was sealed from the outside world on January 23, with the cancellation of all flights, trains and buses and the entrances of the blocked highways.
Still, the Chinese government has announced that major measures have allowed the country to turn the corner in its fight against the outbreak.
The Chinese CDC, meanwhile, also highlighted China’s victory in containing the virus by publishing the results of the antibody study on Monday.
“The results of the study show that the population of our country has a low infection rate. It indicates that China has managed to control the epidemic with Wuhan as the main battlefield and has effectively controlled the large-scale spread of the epidemic, ”the agency said. .
CNN’s Nick Paton Walsh contributed to this story.