The control measures imposed in Wuhan (China) during the first 50 days of the Covid-19 epidemic could have prevented the spread of more than 700,000 people in the country and delayed the spread of the coronavirus to other cities.
This is the main conclusion of a study led by the University of Oxford (United Kingdom) and published today in the journal «Science». The findings of the work could be useful for countries that are in the early stages of the Covid-19 outbreak.
Christopher Dye, a professor at Oxford University, indicates that around 300,000 people were infected with Covid-19 on the 50th day of the epidemic, that is, on February 19.
China’s control measures appear to have worked by successfully breaking the chain of transmission and preventing contact between infected and susceptible people.
“Without the travel ban in Wuhan and the national emergency response there would have been more than 700,000 confirmed cases of Covid-19 outside of Wuhan on that date. China’s control measures appear to have worked by successfully breaking the chain of transmission and preventing contact between infected and susceptible people. ”
The researchers used a combination of case reports, human movement data and public health information to analyze the spread and control of Covid-19. They examined the movements of 4.3 million people outside Wuhan before the travel ban, the types and timing of control measures put in place in Chinese cities, and the number of documented Covid-19 cases each day in each locality.
“Since the time period we studied included Spring Festival holidays and Chinese Lunar New Year, we were able to compare travel patterns in and out of Wuhan during the outbreak with mobile phone data from two previous spring festivals,” indicates Ottar Bjornstad, professor of entomology and biology at Pennsylvania State University (USA).
Bjornstad notes that there was an extraordinary reduction in mobility after the ban on entering or leaving Wuhan on January 23. This could also calculate the likely reduction in cases associated with Wuhan in other cities in China.
This delay provided additional time to prepare for the arrival of the Covid-19 in more than 130 cities.
The scientists also analyzed the specific effects of the Wuhan closure and found that the confinement postponed the arrival of the coronavirus to other cities for several days. “This delay provided additional time to prepare for the arrival of Covid-19 in more than 130 cities,” said Huaiyu Tian, professor of epidemiology at Peking University.
These cities banned public gatherings, closed entertainment venues, and public transportation, among other actions. Consequently, there were 33% fewer infected people in the first week than in places that did not implement that response to the epidemic.
Although these control measures have reduced the number of coronavirus infections to very low levels, China is not out of the woods. “Given the small fraction of the Chinese population that has been infected, a much larger number of people are still at risk for Covid-19,” adds Apostle Tian, who warns: “Resident or imported infections could trigger a resurgence of transmission.”
Bjornstad noted that the SARS-CoV-2 coronavirus may be endemic worldwide for years to come. “It is essential to keep in mind that this virgin epidemic will likely affect people of different ages and susceptibilities and, therefore, will have different levels of mortality than possible subsequent seasonal epidemics,” he concludes. .