Concerns are mounting over a new, potentially fatal, respiratory virus that is spreading in Wuhan, China.

Chinese officials said Saturday that 45 people have contracted the virus, four more than the last figure released.

According to scientists in London, this is likely far fewer than the real total.

Using statistical modelling, the academics from Imperial College London suggested the true number of infected people is somewhere around 1,723 as of January 12.

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Scientists have warned that official totals from Chinese authorities of how many people have been infected with a deadly and little-understood new virus could be out by a factor of 35.

According to public health officials in Wuhan, central China, 45 people have been infected with 2019-nCov, the scientific name for a new, viral strain of pneumonia. Two of the patients have died.

However, according to an analysis from Imperial College London, the number of people to be infected as of January 12 (per the study) is likely more in the region of 1,723 – a figure around 35 times greater than the 45 cases confirmed in a lab.

Their analysis relies on statistical projection to figure out how widely the virus has spread from its point of origin at a seafood market in Wuhan.

It hinges on the fact that three cases have been detected abroad: two in Thailand and one in Japan.

Given that only around 3,400 of Wuhan’s 19 million residents take international flights each day, the experts said that in order for three infected people to have made it abroad, the total number must be in the thousands.

Foto: The Huanan Seafood Wholesale Market in Wuhan, China, which was sealed off after being identified as the epicenter of a new virus.sourcePhoto by Noel Celis/AFP via Getty Images

The scientists admit that their method is imprecise. As well as the 1,723 figure from their preferred scenario, the team of five academics gave other possible figures. The lowest was 996 and the highest 2,298.

Here is the academics’ conclusion:

“It is likely that the Wuhan outbreak of a novel coronavirus has caused substantially more cases of moderate or severe respiratory illness than currently reported.

“The estimates presented here suggest surveillance should be expanded to include all hospitalised cases of pneumonia or severe respiratory disease in the Wuhan area and other well-connected Chinese cities.”

In the US, three airports that receive passengers from Wuhan have begun screening passengers for the disease, in the hope that they can stop it from infecting Americans.

The airports are San Francisco International Airport, Los Angeles International Airport, and New York’s John F. Kennedy International Airport.

Similar screening has begun in Singapore and Hong Kong, according to the BBC.