China says it will stop reporting asymptomatic COVID-19 cases since they have become "impossible" to track with mass testing no longer required, another step in the country's uncertain exit from some of the world's strictest antivirus policies.

The government last week announced its most significant easing yet of antivirus measures and has begun to see what appears to be a rapid increase in new infections, raising concerns that its health system could become overwhelmed as those in other countries did during early COVID-19 waves.

So far, though, many of those newly sick are staying home and there has been little evidence of a surge in patient numbers.

But it is difficult to get a clear picture of the virus' spread, and the new reporting rules could make that even harder.

Some hospitals have reportedly struggled to remain staffed because of rising infections among their employees.

A notice on the National Health Commission's website on Wednesday said it stopped publishing daily figures on COVID-19 cases where no symptoms are detected since it was "impossible to accurately grasp the actual number of asymptomatic infected persons," which have generally accounted for the vast majority of new infections.

The only numbers the commission is reporting are confirmed cases detected in public testing facilities where symptoms are displayed.

Many people also test at home - and any positive results there would also not be captured.

China's government-supplied figures have not been independently verified and questions have been raised about whether the ruling Communist Party has sought to minimise numbers of cases and deaths.

While many governments have long focused on only the more serious cases, the latest move is part of a sea change for China, which has maintained a "zero COVID" policy that seeks to stamp out all virus transmission.

That included frequent mass testing campaigns, and it meant that anyone who tested positive was isolated in a government facility, even if they had no symptoms.

Now people can recover at home if they do not need medical care.

While many greeted the relaxing of the rules with relief, the rapid shift has also caused some concern - after years during which the Chinese government talked about the virus as a major threat.

"Beijing is really confused right now," one resident, surnamed Zhu, said.

"They made a complete 180-degree turn without even going through a transitionary period."

Zhu, who refused to provide his full name to speak on what could be seen as a sensitive topic in China, said he was not able to find a test after developing a sore throat and a fever.

Authorities have said they will provide 25 million rapid test kits for Beijing pharmacies after a rush on such supplies.

Despite the easing, the streets of many major Chinese cities have grown eerily quiet as many people stay home, not because they have to, but because they are worried they will contract the virus at a time when social media is lighting up with reports of infections.

Without asymptomatic cases being counted, China reported just 2249 "confirmed" infections on Wednesday, bringing the country's total to 369,918 - more than double the level on October 1.

It has recorded 5235 deaths - compared with about 16,490 in Australia and 1.1 million in the United States.

President Xi Jinping's government is still officially committed to stopping virus transmission.

But the latest moves suggest the party will tolerate more cases without quarantines or shutting down travel or businesses as it winds down its "zero-COVID" strategy.