Nigeria, Belarus and Lithuania on Friday announced their first confirmed cases of the novel coronavirus.

The Nigeria case, involving an Italian citizen who works in the country and returned from Milan earlier this week, is the first confirmed COVID-19 infection in the sub-Saharan Africa.

"The patient is clinically stable, with no serious symptoms, and is being managed at the Infectious Disease Hospital in Yaba, Lagos," Health Minister Osagie Ehanire said in a statement on Twitter.

Italy has become a hotbed of infection in recent days, with the largest outbreak in Europe.

But the low number of cases across Africa, which has close economic ties with China, the epicentre of the deadly outbreak, has puzzled health specialists.

Prior to the case in Nigeria, there had been just two cases across the continent -- in Egypt and Algeria.

The World Health Organization warned earlier this week that African health systems were ill-equipped to respond should cases start to proliferate on the continent.

However, Ehanire said the government had been working to ensure an outbreak is "controlled and contained quickly".

"I wish to assure all Nigerians that... we have been beefing up our preparedness capabilities since the first confirmation of cases in China," he said.

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

The outbreak, which began in December, has already killed more than 2,800 people and infected more than 78,000 in China.

WHO chief Tedros Adhanom Ghebreyesus said the spread of the virus to countries with weaker health systems was "our biggest concern".

"These patients require intensive care using equipment such as respiratory support machines that are, as you know, in short supply in many African countries and that's a cause for concern," he said.

Several African carriers including Kenya Airways have suspended flights to China, although the continent's biggest airline Ethiopian Airlines has kept its China routes open.

Belarus

Belarus reported Friday its first coronavirus case, an Iranian student who arrived in the country from Azerbaijan last week.

The health ministry said the patient was in a "satisfactory" condition.

People the student had been in contact with since their arrival on February 22 had been placed in quarantine in the hospital for infectious diseases in the capital Minsk, it added in a statement.

The ministry also said that there would now be health checks on anyone arriving in the country from Italy -- the worst affected country in Europe -- Iran and South Korea.

Travellers from China were already subject to such controls.

Lithuania

Lithuania confirmed its first case of the novel coronavirus in a woman who returned from Italy, the government said on Friday. 

The 39-year-old, who returned from Verona, has been isolated in hospital in the Baltic state's northern city of Siauliai and has mild symptoms. Her family members are being monitored. 

"We are putting all efforts to establish all people who contacted the infected person so that we can adopt preventive measures and (stop) the spread of the virus," Deputy Health Minister Algirdas Seselgis said in a statement. 

More than 83,000 people have been infected worldwide and more than 2,800 have died, mostly in China, where the virus originated late last year.

Switzerland

The Swiss government on Friday said it was suspending all events in the country involving more than 1,000 participants until March 15 in a bid to stop new coronavirus contagion.

"Large-scale events involving more than 1,000 people are to be banned. The ban comes into immediate effect and will apply at least until 15 March," the government said in a statement after the country registered 15 cases.

"In the case of public or private events at which fewer than 1,000 people would gather, event organisers must carry out a risk assessment in conjunction with the competent cantonal authorities to decide whether or not the event can be held".

The government said it was "aware that this measure will have a significant impact on public life in Switzerland" but added that "it should prevent or delay the spread of the disease, thus reducing its momentum".

The federal government said that the scale of the outbreak allowed it to take special powers to order measures that are normally the responsibility of Switzerland's cantons.

"The cantons are responsible for enforcing the ban," the statement said.

Health Minister Alain Berset said that similar measures had proved "effective" in other countries.

He told reporters that the number of cases in Switzerland was "not a surprise for us", adding: "We have to expect an increase in cases in the next few days".