18 people have died from an outbreak of a new coronavirus strain that originated in Wuhan, China, including the first outside of the immediate area, provincial authorities said Thursday.The latest: Major Chinese cities, including Beijing, have canceled large public gatherings for the Lunar New Year holiday, to help contain the outbreak, according to the Washington Post. The holiday is the most popular festival in the country, and millions of Chinese citizens travel to their hometowns for public celebrations over a week-long period.Beijing's Forbidden City, one of the country's top tourist attractions, also said Thursday it would close its doors to tourists until further notice.What's happening: Health officials confirmed earlier this week that the pneumonia-like virus can be passed person-to-person. The number of confirmed cases in China has increased to 617, according to the WashPost. Additional cases in Beijing, Shanghai and Shenzhen, three of country's largest cities, have been validated.The Chinese government over Wednesday and Thursday locked down the cities of Wuhan, Huanggang and Ezhou, collectively home to nearly 20 million people, AP reports.The big picture: CDC officials said Tuesday there's one case in Washington state. In the U.S., the Centers for Disease Control and Prevention is rolling out a "funneling" of flights directly or indirectly from Wuhan, China, to five specific airports where screening will be done, adding Chicago and Atlanta to prior designated screening airports.South Korea, Japan, Hong Kong, Taiwan, Singapore and Vietnam have confirmed at least one case of the new virus. Thailand has four cases. The patients had all traveled from the Wuhan area, according to the Wall Street Journal. In Australia, a man in Brisbane was isolated after exhibiting symptoms after a vacation in China, but he ultimately tested negative, authorities confirmed to News.com.au.North Korea is temporarily banning foreign tourists in response to the outbreak, according to Reuters.What they're saying: Dr. Mike Ryan, director of the World Health Organization, said in a press conference Wednesday new that the virus is "showing stability and not showing divergence or any unusual activity.""People's lives and health should be given top priority and the spread of the outbreak should be resolutely curbed," Chinese President Xi Jinping said Monday, according to Reuters. What's next: A possible live animal source is still being investigated in China. The WHO decided Wednesday not to declare an international health emergency yet, but plans to meet again this week.Go deeper: U.S. to begin airport screening for new China virus as concerns growEditor's note: This story has been updated with more recent developments.