HONG KONG: At least 1,300 individuals in the Chinese city of Wuhan are likely to have been infected with a novel coronavirus between Jan 1 and Jan 17, a team of scientists at the University of Hong Kong said at a press conference on Tuesday (Jan 21).
The scientists based their research on their experience of studying the spread of SARS (Severe Acute Respiratory Syndrome) in Hong Kong in 2003 and the spread of MERS (Middle East Respiratory Syndrome) in South Korea in 2015.
They said they had used the number of cases exported from Wuhan to other countries in arriving at their conclusions, taking into account air, train and road traffic.
On Tuesday, China reported its fourth death from the new strain of coronavirus and 291 cases of infected patients, whose symptoms included fever, coughing and difficulty breathing.
The death toll has risen to six in Wuhan.
"Our best guess in terms of the mode, which is the most likely number, is somewhere in the region of 1,300 plus," said Professor Gabriel Leung from the university's faculty of medicine.
"If you take the average, the arithmetic average, which is the mean, and because the distribution of the probability density function is skewed to the right, with a right tail, therefore, it's a slightly bigger number. And it's roughly just under 1,700."
He added: "It is absolutely critical that public health authorities recognise a super-spreading event in the very earliest stages. Before it goes absolutely explosive."
The disease has spread beyond Wuhan to other Chinese cities, with Beijing and Shanghai confirming their first cases on Monday while more than a dozen others emerged in southern Guangdong province.
Cases have also been identified in Japan and South Korea, and health authorities around the world have started stepping up screening of travellers from China.
Little is known about the new virus, including its origin, but health authorities have confirmed human-to-human transmission.
Some experts say the strain may not be as deadly as some other strains of coronavirus such as SARS, which killed nearly 800 people worldwide during a 2002/03 outbreak that also originated from China.