Hours before health authorities in the central Chinese city of Wuhan reported a fourth death Tuesday from the novel coronavirus that has the country on edge, the head of the team tasked with managing the outbreak said there is “definitely human-to-human transmission.”

Zhong Nanshan, a renowned scientist who helped expose the scale and severity of the SARS outbreak in 2003, confirmed Monday that some of the newly identified novel coronavirus cases in the country are not linked to Wuhan, where the virus originated.

So far, official reports say four people have died and a total of 219 have been infected, including 198 in Wuhan, 14 in Guangdong, five in Beijing, and two in Shanghai.

“It is no longer an accidental and scattered disease, and it is more than animal-to-human (transmission),” Zhong said at a press conference in the Chinese capital attended by a group of experts from the National Health Commission.

The scientist said two patients in Guangdong with no history of traveling to Wuhan contracted the virus from family members who had visited the city.

On Tuesday, a commentary published by the social media account of China’s authoritative Central Political and Legal Affairs Commission urged officials to learn from the painful lessons of SARS and warned that anyone caught covering up infections would be “nailed on the pillar of shame for eternity.”

With the number of infections in Guangdong rising to 14 after a new case was reported Monday, the southern province has the most cases of any region in the country outside of Wuhan. Infections have been confirmed in four Guangdong cities — Shenzhen, Zhuhai, Zhanjiang, and Huizhou — according to the provincial health commission.

Wuhan’s health commission on Tuesday confirmed that 15 medical staff in the city have been infected, along with one additional suspected case. Of these 16, who are all under quarantine, one person is said to be in “very serious” condition, while the others are stable.

Wuhan’s health commission told CCTV, China’s state broadcaster, that the city has enforced access controls to curb the spread of the virus: Tour groups from other areas of China must remain in Wuhan for the time being, and local officials are checking private vehicles entering and leaving the city for wild animals and birds.

There are several suspected cases hundreds of miles from Wuhan, too, in the eastern provinces of Zhejiang and Shandong, the southwestern Yunnan province, and the southern Guangxi Zhuang Autonomous Region, according to the state-run Xinhua News Agency.

Zeng Guang, a scientist at the Chinese Center for Disease Control and Prevention, said the recent spike in the number of infections can be attributed to health authorities’ evolving knowledge of the virus. “Today’s understanding is different from yesterday’s,” he said at Monday’s press conference.

Though Zeng says the uptick in cases isn’t altogether surprising, he suggests staying away from the epicenter over the Lunar New Year travel rush, when an estimated 3 billion trips are expected to be made as people cross the country to be reunited with their families.

“We hope that people will not travel to Wuhan, and that people in Wuhan will stay put if they can,” Zeng said, adding that this view was not an “official call,” but rather a “suggestion” from the team of experts.

Meanwhile, the World Health Organization has not issued travel advisories or recommended trade restrictions in response to the outbreak. On Tuesday, the WHO said an emergency committee focused on the new virus will meet Wednesday at its headquarters in Geneva.

Many online are urging rail and air travel providers and booking companies to offer refunds for already-purchased tickets, in the event that people end up changing their travel plans because of the coronavirus outbreak. One of China’s largest travel companies, Trip.com, said Tuesday that users would be allowed to cancel their bookings to Wuhan over the Lunar New Year without facing additional fees.

The National Health Commission on Tuesday categorized the Wuhan coronavirus as a Class B infectious disease, the same category as its cousins, severe acute respiratory syndrome (SARS) and Middle East respiratory system (MERS). It added, however, that authorities would employ strategies devised for Class A pathogens — the most dangerous, most infectious disease category that includes cholera and plague — to stabilize the outbreak.

Editor: Bibek Bhandari.

(Header image: Commuters are seen wearing masks at a subway station in Shanghai, Jan. 21, 2020. Ji Guoliang for Sixth Tone)