The World Health Organisation says it’s too early to say whether China’s coronavirus outbreak is peaking, as the country recorded its first day of a drop in the number of new infections.

The death toll from the virus in mainland China jumped by 73 to 563, with more than 28,000 confirmed infections inside the world’s second-largest economy.

That number had risen by nearly 4000 from Wednesday to Thursday.

The WHO’s top emergencies expert Dr Mike Ryan said it was very difficult to make predictions on the course of the disease, which was first reported in the central city of Wuhan in late December.

“We are still in the middle of an intense outbreak,” Ryan told a news conference on Thursday.

“There are cycles of transmission, and we may see those cases increase in the coming days. But at least for the moment, things are stable,” he said.

“But 4000 cases or nearly, 3700 coronavirus cases confirmed in a single day, is nothing to celebrate and is certainly still a great worry.”

There is a constant rise in infections in the epicentre of Hubei province, which accounts for about 80 per cent of cases, Ryan said.

“But we haven’t see that same acceleration in provinces outside Hubei. And equally we haven’t seen that acceleration in Hong Kong, Macao, in Taiwanese people either.”

WHO director-general Tedros Adhanom Ghebreyesus told reporters it was hard to believe the virus was unknown to the organisation just two months ago.

“We have already learned so much about it, we know its DNA, we know it can be transmitted from one person to another, we know that those most at risk are older people and those with underlying health conditions,” he said.

But there is still a lot to learn, including the source of the virus, its severity and ability to spread, Tedros said.

WHO epidemiologist Maria van Kerkhove said that the virus causes a “full spectrum of disease”.

“You have mild cases which look like the common cold, which have some respiratory symptoms – sore throat, runny nose, fever – all the way through pneumonia.

“And there can be varying levels of pneumonia, all the way through multiple organ failure and death,” she said, calling for further study of mild cases and how easily they can spread the virus.

-AAP