Coronavirus may have infected thousands more than official estimates claim: Lancet's study
BEIJING: The researchers, using, have calculated that up to 75,800 people may have hired the novel in the Chinese city on January 25, a number that is much higher than the official estimate of 1,300 infected people.
According to the study, published in the journal, given the lack of solid and detailed records of suspected, probable and confirmed cases of the new coronavirus infection (2019-nCoV), the true size of the epidemic and its pandemic potential remain unclear.
Not all people infected with 2019-nCoV would require or seek medical attention. During the urgent demands of a rapidly expanding epidemic of a completely new virus, especially when the capacity of the system is being overwhelmed, some of those infected can be counted in the official register, explained lead study author Gabriel Leung of the.
The discrepancy between the model estimates and the actual number of confirmed cases in Wuhan may be due to several factors, such as the delay between infection and the onset of symptoms, delays in infected people who attend medical care and the time needed. To confirm the cases. through laboratory tests, the researchers said.
According to the new estimate, several major cities in China could have imported dozens of cases of 2019-nCoV infection from Wuhan, in sufficient quantities to start local epidemics.
If the transmissibility of 2019-nCoV is similar nationally and over time, it is possible that epidemics are already growing in several major cities in China, with a delay of one or two weeks behind the Wuhan outbreak, said the lead author from the study Joseph Wu of the University of Hong Kong.
Large cities abroad with transport links close to China could also become epicenters of outbreaks due to the substantial spread of pre-symptomatic cases unless substantial public health interventions are implemented immediately at both population and personal levels, Wu added .
In the study, the scientists used mathematical models to calculate the size of the epidemic based on the officially reported case data for 2019-nCoV, and national and international travel data.
They assumed that the time it takes for infected people to infect others for 2019-nCoV was the same as for severe acute respiratory syndrome (SARS), also caused by a pathogen in the coronavirus family.
In their estimate, the researchers also modeled the possible future spread of 2019-nCoV in China and internationally, taking into account the potential impact of several public health interventions implemented in January 2020.
These interventions included the use of facial masks and increased personal hygiene, and quarantine measures introduced in Wuhan on January 23.
Based on these calculations, the researchers said that in the early stages of the Wuhan outbreak, from December 1, 2019 until January 25, 2020, each infected person could have spread the virus to another 2-3 people on average .
They added that the epidemic doubled in size every 6.4 days, probably infecting 75,815 people in Wuhan during this period.
According to the study, cases of 2019-nCoV infection may have spread from Wuhan to several other major Chinese cities as of January 25, including Guangzhou (111 cases), Beijing (113), Shanghai (98) and Shenzhen (80).
The scientists said that, together, these cities account for more than half of all international air travel from China.
With their analysis, researchers believe that the quarantine in Wuhan may not have the desired effect of stopping the epidemic.
If the transmissibility of the virus could be reduced by a quarter in all Chinese cities with expanded control efforts, both the growth rate and the size of local epidemics could be substantially reduced, they added.
A 50% reduction in transmissibility, the team said, can change the current 2019-nCoV epidemic from one that is rapidly expanding to one that is slowly growing.
The researchers urged authorities around the world to prepare preparedness plans and mitigation interventions for rapid deployment, including obtaining supplies of test reagents, medications, personal protective equipment, hospital supplies and human resources.