Updated at 9:40 p.m. ET
The deadly strain of coronavirus that emerged in Wuhan has now spread to every part of mainland China, from Shanghai to Tibet. The rapid increase caused the World Health Organization to declare a global health emergency and prompted Russia to close its long border with China.
Late Thursday, the U.S. State Department also issued a "do not travel" advisory for China.
The coronavirus has now been found in at least 20 countries since the outbreak began last month, with the Philippines and India being the latest countries to report cases. It's expected to keep growing: Respiratory virus experts in Hong Kong say they believe the outbreak's peak is still months away, likely in late spring.
"Ben Cowling, a professor of infectious disease epidemiology at the University of Hong Kong, says that in the last few days the trajectory of this outbreak has grown much clearer," NPR's Jason Beaubien reports from Hong Kong. He adds, "Cowling says the outbreak is just getting started, and he expects to see increased levels of transmission globally, including in the United States."
"I think it's quite likely that you will see human-to-human transmission in U.S. cities" within weeks, Cowling said – but it only took a matter of hours for his prediction to come true, as the Centers for Disease Control and Prevention announced Thursday that the first human-to-human spread had occurred in Illinois.
A Chinese passenger who fell ill aboard a cruise ship in Italy was determined not to have the coronavirus Thursday – a finding that gave relief to more than 6,000 people aboard the Carnival Cruise Line-owned Costa Smeralda. Italy's health ministry says the tests it performed on samples from the woman and another passenger were negative.
The ship had returned to its Italian home port of Civitavecchia Thursday morning, at the end of a seven-day cruise through tourism-heavy areas such as Marseille, Barcelona and Mallorca. But instead of disembarking, the passengers were told to stay onboard until tests could determine whether the passenger, a 54-year-old woman from Macau, was carrying the virus.
The ship's medical staff placed the woman and her traveling companion into isolation in the Costa Smeralda's shipboard hospital Wednesday night after suspecting that she might have the coronavirus, Costa Cruises tells NPR.
President Trump has created a special task force to coordinate the U.S. response to the new coronavirus, or 2019-nCoV. Led by Health and Human Services Secretary Alex Azar, the group includes CDC Director Robert Redfield as well as other health, security and transportation officials.
The World Health Organization issued a global health emergency on Thursday after holding its second meeting in as many days on the subject, with WHO Director-General Tedros Adhanom Ghebreyesus telling reporters in Geneva that the virus had "escalated into an unprecedented outbreak and which has been met by an unprecedented response."
Tedros said via Twitter on Thursday that "Person-to-person transmission has been seen in at least 3 countries outside China — Japan, Vietnam and Germany."
The U.S. State Department is arranging further evacuation flights for Americans caught in Wuhan's virtual lockdown, with the U.S. Embassy in Beijing saying additional flights are tentatively set for Monday.
"Those currently in China should consider departing using commercial means," it said in a travel advisory issued Thursday. "The Department of State has requested that all non-essential U.S. government personnel defer travel to China in light of the novel coronavirus."
About 200 Americans were brought to California on Wednesday, on a flight that included diplomats and their families. The new flights will have "capacity for private U.S. citizens on a reimbursable basis," the State Department says.
Nearly 82,000 people were under medical observation in China out of concern that they might have the virus, the Chinese Center for Disease Control and Prevention says.
There are now nearly 9,700 confirmed cases of the coronavirus in China, where the illness has killed 213 people. The majority of the cases are in Hubei province, where Wuhan is the capital. But at least 13 other Chinese provinces have confirmed 100 or more cases of people who have the coronavirus.
Announcing Russia's decision to close its land border with China, Prime Minister Mikhail Mishustin said Thursday that the new restrictions will take effect Friday. Saying the well-being of the Russian people is his top priority, Mishustin said the temporary closures are the result of special circumstances created by the deadly illness.
To reduce the chance of spreading any respiratory illness, the CDC recommends that people take simple steps such as washing hands with soap and water for at least 20 seconds and avoiding close contact with anyone who is sick.