Study finds number of unrecorded coronavirus cases in China

The number of people infected with COVID-19 during the first wave of China's outbreak may be up to four times higher than official figures suggest, new analysis has found, Report informs, citing Telegraph.co.uk.

By February 20, authorities in China had reported roughly 55,000 cases – but according to modeling published in The Lancet, this figure could have been as high as 232,000 had a broader case definition been applied from the outset of the epidemic.

Between January 15 and March 3, China's national health commission issued seven different case definitions for classifying coronavirus patients.

Researchers at the University of Hong Kong calculated how the changing definitions had altered the trajectory of the country's epidemiological curve based on data published by the World Health Organisation after a visit to China in late February.

The new analysis found that the changes in case definitions had a "substantial effect" on the figures, and adjustments increased the proportion of infections detected and counted by between 2.8 and 7.1 times.

The novel coronavirus (COVID-19) emerged in late 2019 in China's Hubei province, and the virus has spread to 210 countries and territories since then.

To date, COVID-19 cases have reached 2,661,518 globally, resulting in 730,843 recoveries and 185,504 deaths.

On February 11, the WHO officially named the 2019 novel coronavirus (2019-nCoV) as COVID-19, and on March 11, declared it a pandemic.