Coronavirus: More than 75,000 could be infected in Wuhan, major cities under threat, says new Lancet study
More than 75000 persons in the central Chinese city of Wuhan, the epicentre of the novel Coronavirus outbreak, could have been infected by the virus, the prestigious medical journal Lancet said Friday, adding that many major cities in the country could also be primed for localised epidemics.
“New modelling research, published in The Lancet, estimates that up to 75,800 individuals in the Chinese city of Wuhan may have been infected with 2019 novel coronavirus (2019-nCoV) as of January 25, 2020,” the publication said in the latest study unveiled late on Friday.
The modelling study, shared with HT, suggested that “…multiple major Chinese cities might have already imported dozens of cases of 2019-nCoV infection from Wuhan, in numbers sufficient to initiate local epidemics”.
The study was conducted by researchers from the University of Hong Kong.
It estimates that in the early stages of the Wuhan outbreak-- from December 1, 2019 to January 25, 2020-- each person infected with 2019-nCoV could have infected up to 2-3 other individuals on average, and that the epidemic doubled in size every 6.4 days. “During this period, up to 75,815 individuals could have been infected in Wuhan,” it says.
“Additionally, estimates suggest that cases of 2019-nCoV infection may have spread from Wuhan to multiple other major Chinese cities as of January 25, including Guangzhou (111 cases), Beijing (113), Shanghai (98), and Shenzhen (80). Together these cities account for over half of all outbound international air travel from China,” the study added.
Lead author Professor Joseph Wu from the University of Hong Kong said if the transmissibility of the virus is similar nationally, then it is possible that epidemics could be already growing in multiple major Chinese cities with a time lag of one to two weeks behind the Wuhan outbreak.
Wu said some large cities outside China could also become outbreak epicentres.
“Large cities overseas with close transport links to China could potentially also become outbreak epicentres because of the substantial spread of pre-symptomatic cases unless substantial public health interventions at both the population and personal levels are implemented immediately.”
The authors also pointed out the limitations of the study.
The accuracy of the estimates depends on their assumption about the “zoonotic” (animal to human transmission) source of infection in Wuhan.
They highlighted that their models assume travel behaviour of the people was not affected by disease status and that all infections eventually have symptoms—so it is possible that milder cases may have gone undetected which could underestimate the size of the outbreak.