The authorities in Beijing placed a swath of the city under lockdown on Monday and tested tens of thousands of people as they rushed to contain a new coronavirus outbreak that marked an unnerving breach in China’s capital.
President Xi Jinping had said from the outset that Beijing, the seat of Communist Party power and a crowded metropolis, should be a fortress against the pandemic, and local officials have imposed strict measures to keep infections low. Until now, the efforts appeared to have protected the capital against the virus after it emerged late last year in Wuhan, a city in central China.
While the dozens of new cases in Beijing seem slight compared to the hundreds and even thousands of infections reported daily in other countries, the fresh outbreak has jolted China, prompting the government to fire local officials and reinstate some recently relaxed restrictions. The resurgence of cases points to the challenges that governments around the world face as they reopen economies while the virus persists.
“We feel this is dangerous,” Chen Xiaoxi, the owner of a shop about two miles from a market linked to the new outbreak, said by telephone. He said he was waiting for the results of a nucleic acid test to check if he had the virus. “It is a worry; everyone is worried. This is no ordinary disease. We’re waiting at home and can’t go out.”
The city government said on Monday it had tracked down 79 coronavirus infections over the previous four days, including 36 confirmed on Sunday. Virtually all appeared ultimately traceable to the vast, bustling Xinfadi food market in the south of Beijing.
Mr. Xi, who is also the leader of the ruling Communist Party, has not commented publicly on the latest cases, but he previously stressed the importance of controlling outbreaks in Beijing, as well as Wuhan.
“The safety and stability of the capital directly concerns the broader outlook for the party and the country,” he said in February when giving orders about the epidemic.
Some Chinese disease control experts said Beijing appeared to respond to the outbreak quickly. Even so, this failure in the capital’s defenses appeared to rile Mr. Xi’s subordinates. Two local officials and the general manager of the Xinfadi market were dismissed on Sunday for what the city leadership said was a failure to move quickly enough against the infections. A vice premier warned that the outbreak could widen.
“The market is densely packed with many moving around, and the risks are high that the outbreak will spread,” Sun Chunlan, a vice premier overseeing health policy, said at a meeting on Sunday, according to Xinhua, the official news agency. “Take firm and decisive measures to thoroughly prevent its spread.”
Until this outbreak, Beijing had gone 56 days without new locally acquired cases. Officials were mainly concerned that the virus would be carried in by Chinese people returning to the city from abroad.
To stifle the outbreak, the government has brought out a playbook of policies and restrictions honed during China’s nationwide battle against the epidemic.
The authorities shut down and sealed the market over the weekend. City officials were testing 90,000 residents from neighborhoods around the Xinfadi market and another market suspected of a role in the infections, the government said Monday. Residential compounds in those neighborhoods have been sealed, and the authorities were racing to track down and isolate anyone who has been infected. The area is home to many migrant workers from other parts of China.
Beijing city authorities announced on Monday that neighborhoods across the rest of the city would also step up checks, requiring round-the-clock manning of entrances, temperature checks and expanded disinfection. The government banned restaurants from holding wedding banquets and other large gatherings.
Xu Hejian, a spokesman for the Beijing government, said at a news conference on Monday: “We must fully grasp that epidemic containment in the capital is long-term, complex and arduous.”
By Sunday afternoon, 111 people had been ordered into supervised isolation in the Fengtai District, the area of southern Beijing that includes the market, because of their possible contact with infected people. The government said it had requisitioned rooms in 11 hotels to hold people.
Eleven residential areas near the Xinfadi market were placed under strict guard over the weekend to prevent visitors from entering and most residents from leaving. Officials said that students across Beijing in grades that have resumed classes could choose to stay at home if they wished.
Residents near the market described being tested for the virus by medical workers who took throat swabs. One resident, who gave only his surname, Cao, said he was worried that the virus could spread among residents like him as they milled around apartment compounds, waiting to be tested.
While Communist Party leaders appeared to treat the outbreak as almost an embarrassing affront, epidemic experts sought to reassure the public. They said that like other countries, China should get used to the idea that outbreaks were likely even as overall infection rates fell.
“Beijing won’t become a second Wuhan,” Zeng Guang, a senior epidemiologist with the Chinese Center for Disease Control and Prevention, was quoted as saying by the Beijing Daily, the city’s main official newspaper. “Don’t be overwrought. Heed the government’s orders and trust the disease control workers and doctors.”
Still, the burst of cases in Beijing is worrisome because it has been traced to the city’s main food market, where in normal times thousands of traders, suppliers and workers from beyond Beijing jostle with buyers from across the city.
Usually, Xinfadi supplies about 70 percent of the fresh vegetables consumed in Beijing and 10 percent of its pork, a city official said last week. On Monday, officials said that 200,000 people had visited the market since May 30, though that estimate may have included repeat visits.
“The good news is that all the cases are linked to the Xinfadi market, and there have not been cases without a route of transmission,” Zhang Wenhong, a medical expert at Fudan University in Shanghai, said in an online comment on Sunday.
“The bad news is that the capacity of Xinfadi market is astounding, and it’s unclear where a new flash point will emerge,” wrote Dr. Zhang, who has become a prominent voice in Chinese epidemic policymaking.
The infections raise the risk of further cases in shops and restaurants where the food ends up. City officials have rushed to assure residents that other markets will step up their supplies of food.
The customers at Xinfadi include many retail shoppers, especially retirees, who travel far to the market for its varied, cheap produce. The city government ordered anyone who went there recently to report to the authorities.
The government’s aggressive tracing efforts have already indicated that the coronavirus spread among vendors and workers at the market, as well as some people who had shopped there.
As of Monday, however, experts still had not said how the virus arrived in the market. The city government said that traces of the virus turned up on surfaces in the market, including on cutting boards for salmon. The finding brought about unproven theories that the virus was carried on the salmon or workers who handled it, and supermarket chains in the city threw out their stocks of salmon, according to local news reports.
But Wu Zunyou, an investigator from the Chinese Center for Disease Control, said on a government website on Sunday that it would take more time and testing to pin down the source. Many of the first infections in Wuhan late last year were linked to a market that sold seafood and wild game, but officials have yet to say publicly how the virus spread in that market.
Dr. Zhang, the Shanghai expert, said the outbreak in Beijing was a lesson in what Chinese citizens would have to get used to.
“‘Near-zero cases’ will be the normal for China’s epidemic prevention,” he wrote. “I hope that society will adapt to this new normal as soon as possible.”
Amber Wang contributed research.