At least 56 people have now succumbed to the virus, which had been unseen anywhere in the world till about a month ago before it began spreading from the central Chinese city of Wuhan to now sicken people in countries as far away as France, the United States and Australia.
Chinese authorities said on Sunday that the number of coronavirus infections has reached close to 2,000 — a 54% jump in just 24 hours — giving out worrying new details about a pathogen that is now believed to be spreading faster and, often, without people knowing if anyone in their midst is infected.
At least 56 people have now succumbed to the virus, which had been unseen anywhere in the world till about a month ago before it began spreading from the central Chinese city of Wuhan to now sicken people in countries as far away as France, the United States and Australia. On Sunday, a case was “presumptively confirmed” in Canada, and a person in Ivory Coast was isolated for suspicion of infection, in what could be the first case in the African continent.
The dizzying spread of the virus appeared to be explained by two new studies based on preliminary data, which suggested that each person carrying the virus is passing it on to 2-3 people on an average. The current infection figures, both studies say, are likely to increase manifolds if efforts to contain the spread are not intensified.
“The spreading ability of the virus is getting stronger,” China’s national health commission (NHC) minister, Ma Xiaowei said on Sunday, adding that the incubation period (the point from when a person is infected till the first symptoms appear) can range from one to 14 days, and that the virus is infectious during incubation.
Confirmation of a silent outbreak poses a new challenge for authorities around the world, most of whom have till now regarded the flu-like symptoms as the threshold for isolating suspected patients. During the Severe Acute Respiratory Syndrome (SARS) outbreak, a coronavirus that also originated in China and went on to kill nearly 800 people globally in 2002 and 2003, the infection spread only when the patient was symptomatic.
According to an analysis of reported infection numbers, a team of researchers from Imperial College London said the virus appears to have a basic reproduction number (often also calculated as R0) of 2.6 – which means that on an average, one infection can lead to 2.6 more infections.
“R0 estimates for flu pandemics lie in the 1.5-2.5 range… An epidemic with an R0 of 2.5 could still infect between 60% and 90% of the population, depending on contact patterns and assuming no prior immunity. Not all might be symptomatic though,” one of the lead authors of the report, Neil Ferguson, an infectious disease specialist at Imperial College London, said in a tweet on Saturday.
“It is unclear at the current time whether this outbreak can be contained within China,” Ferguson was quoted as saying by news agency Reuters.
A second study derived a similar rate of infection (basic reproduction number of 2.5) and said that their projections showed Wuhan could have 190,000 cases by February 4. “In 14 days’ time (4 February 2020), our model predicts the number of infected people in Wuhan to be greater than 190 thousand,” said the study by researchers at Lancaster University.
Scientists around the globe have been working to understand the virus better, how contagious it is and where it comes from. First detected in Wuhan last month when it caused cases of pneumonia, it has sparked fears that the disease could rival SARS.
Containment efforts, which have thus far included transportation and travel curbs, and the cancellation of big events, will be intensified, Ma said.
China has virtually locked down the Hubei province – of which Wuhan is the largest city – grounding flights and blocking of road and train routes. Chinese President Xi Jinping on Saturday described the outbreak as a “grave situation”.
Wuhan also has a significant number of Indian residents, most of them students who are believed to have returned to India for the Lunar New Year holidays that began last week. Indian officials have estimated the around 150 Indians are still trapped in the city, and there are talks with Chinese authorities of a possible evacuation.
Several countries, such as US, France, Australia and Japan, have announced plans to evacuate their citizens.