New Zealand and Nigeria report first confirmed cases of coronavirus infection

Nigerian health ministry says infected Italian man arrived three days ago in Lagos, the most populated city on the African continent

New Zealand prime minister Jacinda Ardern attends a press conference in Sydney, where she was meeting Australian prime minister Scott Morrison (EPA)

New Zealand's prime minister said on Friday that the country has confirmed its first case in the novel coronavirus outbreak that began in China and is now rapidly spreading around the world.

Separately, Nigeria's health ministry said it too had received its first case, an Italian man who arrived from Milan three days ago in Lagos, the most populous city on the African continent.

Speaking in Sydney, New Zealand's prime minister Jacinda Ardern said the infected person was a New Zealand citizen who returned to the country from Iran.

The patient, a person in their sixties, was in a "stable, improving condition" in isolation at Auckland Hospital, Ms Ardern said.

"A pandemic plan always exists in New Zealand. We've been well prepared. We are rolling out all of the protocols as we would expect," she added.

Earlier, health minister David Clark had announced temporary restrictions on incoming travellers from Iran, where the death toll from the virus of 26 is by far the highest of any country outside China.

"This means people will not be able to travel from Iran to New Zealand and anyone who has been in Iran in the last 14 days will need to self-isolate," Mr Clark said in a statement.

New Zealand also decided not to allow any exemptions for overseas students from China to enter the country, and that there will be extra health staff to meet flights arriving in New Zealand from Hong Kong, Japan, South Korea, Singapore and Thailand.

Meanwhile, Nigeria's health ministry wrote in a tweet that its first confirmed case - which is also the first anywhere in sub-Saharan Africa - is an Italian who works in Nigeria, and arrived back in the country on 25 February.

Health minister Osagie Ehanire said in a statement that the patient's infection was confirmed by lab testing carried out by the Nigeria Centre for Disease Control.

"The patient is clinically stable, with no serious symptoms," said the minister, adding that he was being treated at a hospital in the Lagos district of Yaba.

"We have already started working to identify all the contacts of the patient, since he entered Nigeria," Mr Ehanire said.

Mainland China reported just 327 new cases on Friday, the lowest number since 23 January, taking its total cases to more than 78,800 with almost 2,800 deaths.

But with countries other than China now accounting for about three quarters of new infections, World Health Organisation director-general Tedros Adhanom Ghebreyesus said all nations should prepare.

"This virus has pandemic potential," Tedros said in Geneva on Thursday. "This is not a time for fear. This is a time for taking action to prevent infection and save lives now."

Including New Zealand and Nigeria, about 12 countries reported their first virus cases in the past 24 hours.

Outside China, the virus has now spread to 46 countries, where about 3,700 cases and 57 deaths have been reported, according to the WHO.

Ratings agency Moody's said a coronavirus pandemic would trigger global and US recessions in the first half of the year.

Additional reporting by agencies