Countries began evacuating their citizens Wednesday from the Chinese city hardest hit by a new virus. The coronavirus has infected more people in China than were sickened in the country by the severe virus known as SARS.

The number of confirmed cases jumped to 6,078, more than the 5,327 in mainland China during the SARS outbreak in 2002-2003.

The death toll rose to 132, which is still lower than the 348 people who were killed in China by SARS, which stands for severe acute respiratory syndrome. Scientists say there are many questions to be answered about the new virus, including how transmissible and severe it is. Virus symptoms include cough and fever and in severe cases pneumonia.

The United States and Japan evacuated 200 of their citizens from the city of Wuhan, which Chinese authorities have shut down to try to contain the virus. Airlines announced they were cutting flights to China, and Hong Kong was suspending rail travel to and from the mainland at midnight.

The U.S. plane was headed to California on Wednesday after a refueling stop in Alaska. All 201 passengers, who included diplomats from the U.S. Consulate in Wuhan, passed health screenings in China and Anchorage.

In China’s Hubei province, 17 cities including Wuhan have been locked down, trapping more than 50 million people in the most far-reaching disease control measures ever imposed.

Sara Platto, an Italian animal behavior researcher and veterinarian, said there were 25 Italians stuck in Wuhan who stay in touch online.

“My son turned 12 on January 23, the first day of the lockdown in Wuhan. So he couldn’t invite his friends over. We had a remote birthday celebration, with people ‘visiting’ him over WeChat,” Platto said, referring to a Chinese messaging app. “We called it the epidemic birthday.”

People spending most of their times indoors have to deal with boredom.

Her son Matteo usually has a very busy agenda between his school, sports and volunteer work, but now “it’s like suddenly everything has slowed down,” Platto said. As with other international schools, classes are moving online until the all-clear is sounded.

The new virus is from the coronavirus family, which includes those that can cause the common cold as well as more serious illnesses such as SARS.

The source of the virus and the full extent of its spread are still unknown. But the World Health Organization said most cases so far “have been milder, with around 20 percent of those infected experiencing severe illness.”

Scientists expect many crucial questions about the virus’s behavior will be answered in the coming weeks as the outbreak evolves and it becomes clearer how people are infected.