The Chinese Ambassador to the United States, Mr Cui Tiankai, condemned as "absolutely crazy" US Senator Tom Cotton's claim that the Covid-19 outbreak is linked to some Chinese biowarfare research programme.
From the other end of the conspiracy mill are theories of covert US Central Intelligence Agency virus dissemination operations to subvert China's rise.
These incredulous fringe stories are indications of the deep mistrust afflicting Sino-US ties - even as the world is confronted by a looming pandemic crisis.
First to declare a total ban on travel to and from China, Washington was criticised by Beijing for causing panic and spreading fear.
The Americans in turn accused the Chinese of stonewalling and cover-ups.
Months into the crisis, discussion is under way, albeit belatedly, to incorporate US experts into a World Health Organisation (WHO) mission to China. US Secretary of State Mike Pompeo, in a statement, announced America's commitment to sending more aid to the country.
These gestures do not conceal the lingering enmity between the two powers. Last week, at the Munich Security Conference, US Defence Secretary Mark Esper pulled no punches, casting the oft-repeated aspersion that China poses the gravest threat to the world.
An embattled China, in the midst of a national health emergency, is getting no reprieve from its ongoing bitter rivalry with the US.
Media commentary from many Western societies on the coronavirus outbreak has degenerated into a China-bashing session. The Chinese government's containment strategy was decried as draconian, repressive and violating fundamental human rights.
The tragic death of Dr Li Wenliang, the whistle-blower doctor who raised the alarm early about the virus, was headlined as the epitome of all that is wrong with authoritarian China.
This is despite the fact that Beijing has undertaken epic-scale countermeasures, locking down entire cities of millions and mobilising tens of thousands of healthcare workers to keep a lid on the outbreak. WHO officials praised the Chinese state's ability to put the entire country on a war-like footing to fight a contagious disease - a historic feat that could happen only in China.
But in the American moral calculus, any "good" attained by an innately flawed Chinese regime is inevitably tainted.
In what is now a bipartisan and whole-of-government pushback against China, Washington has assumed an increasingly hostile zero-sum approach towards Beijing. As Senator Rick Scott puts it: "There is no reason we should prop up our adversaries with US tax dollars."
US leaders, however, are anxious to clarify that these animosities are directed at China's authoritarian party-state, led by the Chinese Communist Party (CCP) - not the Chinese people.
But the line separating anti-CCP-China rhetoric from anti-Chinese racism is a blurry one.
Already under a cloud of suspicion, Americans of Chinese descent are being subjected to even greater public scrutiny due to the coronavirus outbreak.
To be sure, this virus-induced xenophobia is not confined to the West. In South-east Asia, there is a spike in reported incidents of intra-Asia, even intra-Chinese, paranoia against mainland Chinese citizens. However, as Chinese tourist arrivals trickle to a standstill, countries across the region are feeling the economic pain, which is expected to become more acute in the months ahead.
But it is global public health that faces the most imminent threat as the virus spreads to countries with weaker health systems in place to control the outbreak. Warning of a brewing "global pandemic crisis", WHO is rallying the international community for a unified response.
After some holding back, Beijing is owning up and collaborating with the rest to combat the epidemic.
Yet a besieged China remains wary of American intent.
US sincerity in stemming the contagion is stained by what appears to be Washington's attempt to exploit the crisis: to contain the virus and to stymie a rival, both at the same time.
Since the outbreak, there has been no let-up in the US' multifront onslaught against China. These include provocative naval activities across the Taiwan Strait, Justice Department charges against People's Liberation Army officials for cyber espionage, and the protracted assault on Chinese tech company Huawei, among other things.
To take advantage of a beleaguered opponent is opportunistic - and dangerous - at a time when the world stands at the precipice of an impending global endemic.
Sadly, this is the world of realpolitik. Hardliners on either side of the Sino-US rivalry would have sought to exploit each other's vulnerability.
Yet, the world deserves better. Confucian East and Christian West once shared the universal principle of compassion for all. But these ethical ideals of human benevolence are all but lost to realpolitik's brutish, predatorial law of might makes right.
Humankind's capacity to strive for the common good is compromised. Efforts to contain the virus outbreak have fallen captive to big powers' gamesmanship. Even WHO's critical intermediary role is not spared from politicisation.
The world must recapture our lost humanity and solidarity. Let the scientists deal, unfettered, with the deadly coronavirus that can infect us all, regardless of race and ideology. This is the best way to honour Dr Li and the thousands of healthcare workers battling heroically, risking their lives on the front line.
The coronavirus epidemic has yet to peak. But if and when the outbreak is finally contained, we must count ourselves lucky because we would have survived without the benefit of enlightened leadership. But the world can do better and must do so soonest. For when the next crisis comes along, we may simply be out of luck.
• Dr Peter T.C. Chang is deputy director of the Institute of China Studies, University Malaya. Trained in comparative philosophy, he is currently researching China's rise from the perspective of Chinese soft power's impact upon Malaysia and the wider world.