Hubei authorities have been criticized fiercely for not having responded to the deadly virus in the early stage of the outbreak, which, as of Thursday, had killed 1,368 people and infected more than 50,000 in China.
The drastic jump comes after official figures showed coronavirus cases had dropped for two days in a row.
It is not immediately clear what the region's new method for diagnosing COVID-19 is, or why the number of fatalities has risen so sharply over the past 24 hours.
Meanwhile, Wang Zhonglin has been appointed secretary of the Wuhan Municipal Committee of the CPC and a member of the Standing Committee of the Hubei Provincial Committee of the CPC, replacing Ma Guoqiang.
Dozens of low-level health officials across the country have also lost their jobs for failing to contain the epidemic, which is believed to have emerged from a market in Wuhan where wildlife was traded illegally.
Tests have been taking place to see whether antiviral drugs used to treat HIV are effective against the coronavirus - however, results are only expected in a few weeks.
"This outbreak could still go in any direction", he told reporters.
A security guard stands outside a plastic tent set up to disinfect people coming in at the entrance of a residential compound, as the country is hit by an outbreak of the new coronavirus, in Beijing, China, on February 13, 2020.
"It has spread to other places where it's the beginning of the outbreak", Dale Fisher, head of the Global Outbreak Alert and Response Network coordinated by the World Health Organization, said in an interview in Singapore.
There have been more than 500 infections in nearly 30 countries and territories outside mainland China, including two deaths.
Tedros said a WHO-led advance team that traveled to China this week had made good progress on the composition and scope of its work.
"I think it is way too early to try to predict the beginning, the middle or the end of this epidemic right now", said Michael Ryan, head of the WHO's health emergencies programme.
Another 44 people aboard a cruise ship that has been quarantined for over a week in Japan's Yokohama harbor tested positive for coronavirus Thursday, Japanese health officials said.
Although no passengers have fallen ill on board, the ship had been turned away by Japan, Taiwan, Guam, the Philippines and Thailand over fears that someone on the cruise could have the virus.
Cambodia agreed to let it land, the Holland America Line said.
It was "an example of the worldwide solidarity we have consistently been calling for", he said.
The patient was among 232 people under quarantine at the Marine Corps Air Station Miramar after being airlifted out of Wuhan earlier this month, CDC spokeswoman Ana Toro said.
Also Thursday, central authorities fired the Communist Party chiefs of both Wuhan and Hubei province, replacing them with high-ranking officials known for their background in "stability maintenance" and history of working closely with party chairman and Chinese President Xi Jinping.
Across China, more than 60 million people have been affected by an unprecedented lockdown.