BEIJING — The United States is concealing the true scale of its coronavirus deaths. The United States should learn from China about how to respond to an epidemic. The United States was the origin of the coronavirus — and the global crisis was never China's fault.

Welcome to the Chinese Internet this week.

As new coronavirus cases and the sense of panic ebb in China, the country that was first struck by the disease has been gripped by a wave of nationalist pride, conspiracy theories and a perennial mix of anti-American sentiments: suspicion, superiority, schadenfreude.

Weeks after China’s government came under scrutiny over whether its mismanagement unleashed the coronavirus on the world, officials in Beijing and many ordinary Chinese appear relieved — even happy — to turn the tables and call out missteps in Italy, South Korea and, particularly, a Trump administration that has been roiled by a chaotic response to the gathering crisis.

In recent days, run-of-the-mill mockery of the White House has taken a darker turn as the Chinese Internet became inundated by the theory, subtly stoked by the Chinese government, that the coronavirus originated in the United States. The U.S. government, one version of the theory goes, has been covering up mounting cases, and perhaps thousands of deaths, by classifying them as regular flu.

While conspiracy theories pervade the Internet in every country, the sudden surge and overwhelming prevalence of anti-U.S. rhetoric this week has been conspicuous and significant in the context of China, where censors typically scrub speech that strays out of bounds and police quickly detain those deemed to be spreading rumors.

“Go on WeChat, go on Weibo, look on Baidu search, and it’s full of ‘look at all the other countries getting sick,’ or ‘the virus came from the United States,’ or all different levels of conspiracy theories,” said Xiao Qiang, an adjunct professor at the University of California at Berkeley’s School of Information who studies China’s Internet.

Fringe theories, to be sure, have been widely floated on both sides of the Pacific.

Sen. Tom Cotton (R-Ark.) speculated last month on Fox News that the virus may have escaped from a Wuhan lab that researched dangerous pathogens, repeating a popular theory that had been debunked by scientists.

Some observers of Chinese politics say the crescendo of anti-American sentiment may be a product of organic nationalism or overactive imaginations of millions of Chinese cooped up at home. But Xiao said it was no coincidence that social media — the source of news for most Chinese — was awash in anti-American discourse precisely at a moment when the image of the Communist Party and its leader Xi Jinping has been badly dented after Chinese officials were found to be covering up early information about the outbreak.

“It’s more than just some disinformation or an official narrative,” said Xiao, the founder of China Digital Times, a website that regularly publishes leaked directives from the party’s propaganda department. “It’s an orchestrated, all-out campaign by the Chinese government through every channel at a level you rarely see. It’s a counteroffensive.”

A review of Chinese social media and state media over recent days shows how the anti-American theories gained steam through a mix of unexplained official statements magnified by social media, censorship and doubts stoked by state media and government officials.

The frenzy kicked into overdrive Feb. 27 after Zhong Nanshan, a Chinese pulmonologist who has appeared on state media to deliver key pronouncements, made a passing remark during a news conference, without offering any explanation, that “the coronavirus first appeared in China but may not have originated in China.”

Zhong’s comments were dismissed as unfounded by the reputable Shanghai public health official Zhang Wenhong, yet Zhang’s remarks were quickly censored. Zhong later tried to clarify his comments, but by then, nationalistic social media accounts and state media had pounced.

State outlets began producing headlines that cast doubt on China’s role in unleashing the virus. China Global Television News, the overseas arm of the state broadcaster, uploaded a two-minute clip of Zhong’s remarks to YouTube, garnering tens of thousands of views.

The rumor mill ramped up. Influential Weibo accounts such as “Beijing Things” circulated a Taiwanese television clip showing a pharmacologist speculating about the United States as the contagion’s origin. Writers at popular outlets on WeChat churned out theses laying out how the U.S. military could have deployed the pathogen as a clandestine bioweapon during a trip to Wuhan in October.

On Saturday, the New York-based College Daily, a popular WeChat account for Chinese students studying abroad that toes a nationalistic line, wondered in a headline: “If it’s true that the virus originated in the United States, should China still apologize to the world?”

When the widely followed blogger Heiheig asked in a poll that day whether readers thought U.S. government data on flu cases was suspicious, 91 percent of his 116,000 respondents saw something fishy in U.S.-reported numbers.

“They can’t cure covid-19 so they’re trying to pin it on China!” said one typical response. Others mocked the United States for not being able to produce as many as masks as China.

By Wednesday, Zhong’s comments came full circle. Foreign Ministry spokesman Zhao Lijian did not speculate as to the virus’s origin or name any countries, but he cited Zhong’s comments to conclude that China was never proven to be the origin.

“It’s extremely irresponsible of some media to call the new coronavirus ‘Chinese virus,’ and we firmly oppose it,” Zhao told reporters at a daily briefing. “We have to work together to oppose the ‘information virus’ and ‘political virus.’”

The same day, the state-run Xinhua News Agency republished an essay that suggested the virus originated elsewhere and that called for American officials and journalists to apologize.

Dali Yang, an expert on Chinese politics at the University of Chicago, said he was not convinced that the outpouring of anti-U.S. rhetoric was wholly due to a sophisticated state disinformation campaign. But the flood of posts and essays, many seemingly written by authentic users, aligned neatly with the government narrative that casts doubt on China’s culpability, he said.

“The purpose is to lessen the focus on how China bungled its response,” said Yang. “It’s a kind of blame-shifting.”

Chinese suspicions and criticisms have not been limited to the United States or sinister theories. Online posts have widely panned other governments, from Italy to Japan.

Bill Bishop, an observer of Chinese politics who writes the Sinocism newsletter, said the narrative of Communist Party superiority is being systematically — and effectively — pushed. After Hong Kong’s pro-democracy protests, party leaders resolved in November to double down on propaganda and patriotic education that would tout the advantages of the party’s efficient, authoritarian leadership over chaotic, Western-style democracy, Bishop said.

That argument is gaining traction, Bishop said, adding that his mother-in-law in China has been urging his family to flee their home in Washington for the safety of China.

“She is convincing us that China has won the virus battle and the U.S. is about to descend into chaos,” he said.

It’s unclear how far the rhetoric bashing other countries will go. Many Chinese are expressing dismay at others’ online behavior.

An editorial writer at the state-owned China Youth Daily, Cao Lin, wrote that it was “repulsive” to see Chinese “gloating over misfortune” and “demonizing” other countries as the epidemic goes worldwide.

“It’s belittling other people’s anti-virus efforts to feed or pander to your own sense of vanity,” Cao wrote.

But unlike Cao, others have been quickly silenced for rebuking their compatriots.

Wang Xiaolei, a former state media journalist and popular WeChat essayist, urged Chinese to stop blaming other countries and shoulder some responsibility.

Without referencing the virus, Wang used a lengthy metaphor that compared China with tenants whose apartment floods — and then blame their downstairs neighbor.

“Be a person with a healthy psychology and repair your floor,” Wang wrote in an essay that was criticized by influential state media officials, including Hu Xijin, the editor of the Global Times newspaper, after it was published Friday.

By Sunday, Wang’s essay was censored and had vanished from China’s Internet.