SOURCE: THE NEW YORK TIMES

The Corona Virus, which surfaced in a Chinese seafood and poultry market late last year, has spread to more than 70 countries, killing more than 3,000 and sickening tens of thousands of people in a matter of weeks. The World Health Organization has declared the situation a global health emergency.

Here’s a timeline of the outbreak so far.

On Dec. 31, the government in Wuhan, China, confirmed that health authorities were treating dozens of cases. Days later, researchers in China identified a new virus that had infected dozens of people in Asia.

On Jan. 11, Chinese state media reported the first known death from an illness caused by the virus, which had infected dozens of people.

On Jan. 20, The first confirmed cases outside mainland China occurred in Japan, South Korea and Thailand, according to the World Health Organization’s first situation report.

On Jan. 23, The Chinese authorities closed off Wuhan by cancelling planes and trains leaving the city, and suspending buses, subways and ferries within it. At this point, at least 17 people had died and more than 570 others had been infected, including in Taiwan, Japan, Thailand, South Korea and the United States.

On Jan. 30, Amid thousands of new cases in China, a “public health emergency of international concern” was officially declared by the W.H.O. China’s Foreign Ministry spokeswoman said that it would continue to work with the W.H.O. and other countries to protect public health, and the U.S. State Department warned travellers to avoid China.

On Feb. 2, A 44-year-old man in the Philippines died after being infected, officials said, the first death reported outside China. By this point, the more than 360 people had died.

On Feb. 5, After a two-week trip to Southeast Asia, more than 3,600 passengers began a quarantine aboard the Diamond Princess cruise ship in Yokohama, Japan. Officials started screening passengers, and the number of people who tested positive became the largest number of coronavirus cases outside of China. By Feb. 13, the number stood at 218.

On Feb. 7, When Dr. Li Wenliang, a Chinese doctor, died on Feb. 7 after contracting the coronavirus, he was hailed as a hero by many for trying to ring early alarms that a cluster of infections could spin out of control.

On Feb. 10, The death toll in China rose to 908, surpassing the global number of dead from the SARS epidemic in 2002-3, which killed 774. At this point, the number of confirmed cases of infection in the country had risen to 40,171.

On Feb. 13, Officials added more than 14,840 new cases to the total number of infected in Hubei Province, and the ruling Communist Party ousted top officials there. The new cases set a daily record, coming after officials in Hubei seemed to be including infections diagnosed by using lung scans of symptomatic patients.

On Feb. 14, An 80-year-old Chinese tourist died on Feb. 14 at a hospital in Paris, in what was the first coronavirus death outside of Asia, the authorities said. The health minister of France, Agnès Buzyn, said the man, who was from Hubei Province, the centre of the outbreak, had arrived in France in mid-January and “his condition had quickly worsened.” It was the fourth death from the virus outside of mainland China, where about 1,500 people had died, most of them in Hubei.

On Feb.19, After a two-week quarantine, 443 passengers began leaving the Diamond Princess cruise ship. It was the first day of a three-day operation to offload people who tested negative for the virus and did not have symptoms. Passengers who shared cabins with infected patients remained on the ship. A total of 621 people aboard the ship were infected.

On Feb. 19, Iran announced two coronavirus cases in the country, then hours later said that both patients had died. Two days later, Iran announced two additional deaths. The source of the virus in Iran is unknown. By Feb. 20, the number of global cases had risen to nearly 76,000, according to the W.H.O.

On Feb. 21, Europe faced its first major outbreak as the number of reported cases in Italy grew from fewer than five to more than 150. In the Lombardy region, officials locked down 10 towns after a cluster of cases suddenly emerged in Codogno, southeast of Milan. As a result, schools closed and sporting and cultural events were cancelled.

On Feb. 24, Iran said it had 61 coronavirus cases and 12 deaths, more than any other country but China, and public health experts warned that Iran was a cause for worry — its borders are crossed each year by millions of religious pilgrims, migrant workers and others. Cases in Iraq, Afghanistan, Bahrain, Kuwait, Oman, Lebanon, the United Arab Emirates and one in Canada, have been traced back to Iran.

On Feb. 28, Italy, where 800 people had been infected by Feb. 28, remained an area of concern. Cases in 14 other countries, including Northern Ireland and Wales, could be traced back to Italy. Germany had nearly 60 cases by Feb. 27, and France reported 57, more than triple the number from two days earlier. Both England and Switzerland reported additional cases, while Belarus, Estonia and Lithuania all reported their first infections.

On Feb. 28, Nigeria, Africa’s most populous nation, confirmed its first case of coronavirus on Feb. 28. The patient was an Italian citizen who had returned to Lagos from Milan.

On Feb.29, A patient near Seattle became the first coronavirus patient to die in the United States on Feb. 28 as the number of global cases rose to nearly 87,000.