Weeks after the novel coronavirus crisis began in December, there is still widespread confusion over the exact number of cases reported in China and whether the epidemic is finally stabilizing at the outbreak's epicenter of Hubei province.

On Thursday, China announced just 394 new confirmed cases, the lowest number of daily infections reported in weeks. But on Friday, the confirmed number of cases in mainland China increased to 889, according to the country's National Health Commission.

This fluctuation could be partly down to a change this week in what is counted as a "confirmed case" in Hubei province, the epicenter of the global outbreak.

How has China changed its method? On Thursday the government guidelines changed and "Clinically confirmed" were excluded from the tally of confirmed cases.

Now patients must have a positive lab test result to be counted in the tally. Other cases will be listed as "suspected."

Why has China done this? China cited improved testing capacity of the novel coronavirus as the reason for changing the way confirmed cases are counted in Hubei province, officials said Thursday.

Experts have different takes on the change: The World Health Organization has previously voiced support for the way China is counting coronavirus infections, and said Thursday it was encouraged by the drop in reported cases.

Some experts, however -- including a former US Food and Drug Administration commissioner -- have expressed skepticism over taking China's figures at face value, given the government's track record of suppressing information about this epidemic and previous ones.

But David Fisman, a professor of epidemiology at the University of Toronto, said the way that officials define cases of a virus often evolves as their understanding of the illness develops.

One could change a case definition for sort of nefarious reasons to create the illusion that the epidemic is getting better. In this case, China did exactly the opposite," he said. "They broadened their case definition when they needed to, in order not to miss cases, and now that things are under control they're narrowing it down again to make it consistent to easier to keep track of what's really going on."

But Eric Feigl-Ding, an epidemiologist and visiting scientist at the Harvard T.H. Chan School of Public Health, said to change track twice in one week was "very unusual."

"It's very confusing to see true trends and makes elucidating them complicated," Feigl-Ding continued. "Did (the cases) really decrease or is it because you've been not reporting this the last few days?"

Read the full story here.