A Chinese health worker checks the temperature of a woman entering a subway station during the Chinese New Year and Spring Festival on January 25, 2020 in Beijing, China.

More than 2,800 people in China are now said to have been infected by the fast-spreading coronavirus while more countries have reported their first confirmed cases.

Chinese officials have said there are 2,862 confirmed cases, with the death toll rising to 81.

On Monday, Chinese Premier Li Keqiang visited the epicenter of the outbreak — the city of Wuhan in Hubei province, where the deadly pneumonia-like virus was first identified last month. Li was there to inspect prevention and control efforts, the government said.

The new strain comes from a large family of viruses known as coronaviruses, according to the World Health Organization. They are known to cause illness ranging from the common cold to more severe diseases such as the 2002-2003 outbreak of SARS, or severe acute respiratory syndrome.

It has since spread beyond Wuhan to other major cities such as Beijing, Shanghai, Macao, and Hong Kong.

In a press briefing, the National Health Commission said the incubation period for the virus is about 10 days and that it is contagious even during this stage, putting additional pressure on prevention control. That is said to be a major difference compared to SARS, where victims became contagious after they showed symptoms.