WHO comment supported

Zhang said that entry bans on Chinese citizens or those from the epicenter imposed by some countries were fully understandable, as they may be concerned about the capacity and capability of their healthcare systems to handle the potential patients.

"And therefore, from this perspective, we could say that China's healthcare system stood the test. Dozens of provincial-level regions reported no new infection cases for consecutive days," Zhang said, adding that though the outbreak in Hubei was mainly due to the lack of knowledge about the disease, its spread in the rest of the country was vigorously controlled.

He suggested that it was unnecessary for China to implement border restrictions on other countries before the World Health Organization declared the outbreak a public health emergency of international concern in those countries.

Zhang refuted some critics' doubts about the WHO's impartiality regarding its recent positive comment on China's countermeasures against the spread of the virus.

"The WHO's comment was based on the substantial recent slowdown of the novel coronavirus spread in most parts of China. If there were still small-scale outbreaks or disease clusters, I don't think the organization would have drawn such a positive conclusion," he said.

In response to some claims that the virus was imported from elsewhere, Zhang said he believes it originated in Wuhan.

"If that was the case, we should have seen patients emerging from different regions in the country around the same time rather than their concentration in Wuhan," Zhang said."Moreover, influenza could be easily differentiated from the coronavirus infection through CT scan."

As work gradually resumes, he reiterated that the country still needs to pay close attention to the contagion for the next one to two months and reduce large-scale gatherings.

Measures such as those requiring a 14-day quarantine of people returning to big cities should continue, he said.

"If we properly implement such preventive measures, and the number of new infection cases remains zero for a certain period of time, in one or two months it'll be time to take off masks," Zhang said.