The number of known cases of the new virus rose by nearly a third overnight. A shortage of test kits has led experts to warn that the real number may be higher.

Death toll climbs above 130, and the number of infections jumps as well.

As the outbreak of the mysterious new coronavirus rapidly spreads, the Chinese authorities said on Wednesday that the official count of known cases jumped again overnight, with the death toll now exceeding 130.

◆ China said on Wednesday that 132 people had died from the virus, which is believed to have originated in the central city of Wuhan and is spreading across the country. The previous count, on Tuesday, was 106.
◆ The number of confirmed cases increased to 5,974 on Wednesday, up from 4,515 on Tuesday, according to the National Health Commission.
◆ Most of the confirmed cases have been in the central Chinese province of Hubei, where several cities, including Wuhan, the epicenter of the outbreak, have been placed under what amounts to a lockdown.
◆ Thailand has reported 14 cases of infection; Hong Kong has eight; the United States, Taiwan, Australia and Macau have five each; Singapore, South Korea and Malaysia each have reported four; Japan has seven; France has four; Canada has three; Vietnam has two; and Nepal, Cambodia and Germany each have one. There have been no deaths outside China.

The virus has sickened more than 4,500 people in China and a handful in other countries.

The United States is expanding the screening of travelers arriving from Wuhan — to 20 airports and land crossings, from five airports, federal officials said on Tuesday.

“Right now, there is no spread of this virus in our communities at home,” said Dr. Robert Redfield, director of the Centers for Disease Control and Prevention, at a news briefing in Washington.

“The coming days and weeks are likely to bring more cases including the possibility of person-to-person spread,” he said. “Our goal is to contain this virus and prevent sustained spread of the virus in our country.”