China Coronavirus
FILE PHOTO: A medical staff member is seen by a window at the Jinyintan hospital, where the patients with pneumonia caused by the new strain of coronavirus are being treated, in Wuhan, Hubei province, China January 20, 2020. REUTERS/Stringer/File Photo

The World Health Organization admitted an error on Monday in its previous risk assessment reports of China's deadly coronavirus.

In a situation briefing late Sunday, the Geneva-based UN agency said that the risk was "very high in China, high at the local level and excessive at the worldwide degree."

The health agency explained in a footnote that the agency had stated "incorrectly" in its previous reviews on Thursday, Friday, and Saturday that the global hazard was "moderate."

WHO, however, remained unclear if the deadly coronavirus spreading in China and beyond is contagious during its incubation period before symptoms appear.

The agency also stopped short of declaring the outbreak a public health emergency of international concern. The declaration is a rare designation that is used only for the worst outbreaks that would trigger more concerted global action.

The virus originated in Wuhan, China. The new virus infected thousands of people worldwide, including a few cases, confirmed in over a dozen other countries.

The virus, which can cause a pneumonia-like acute respiratory infection, killed more than 80 people in China in a matter of weeks.

The UN health agency said current estimates placed the incubation period for the virus at between two and ten days, in a new report on the latest virus known as 2019-nCoV.

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A 'good-sized' mistake

WHO leader Tedros Adhanom Ghebreyesus, who is traveling China this week to talk about ways of containing the outbreak, came under excessive questioning from newshounds on Thursday over his selection not to declare the emergency.

At the briefing at WHO headquarters, Tedros said the decision could be changed at any moment and that the global risk from the outbreak became "high."

"WHO's risk assessment is that the outbreak is a very high risk in China, and a high risk regionally and globally," Tedros said.

WHO stated the categorization is based on "a global evaluation of risk, protecting severity, unfold and ability to cope."

The organization clarified that the error made in three of its scenario reports had been a "mistake in the wording."

"It's certainly a sizeable [mistake]," Antoine Flahault, co-director of the Swiss School of Public Health, remarked when asked about the error.

"I virtually presume it is a mistake that has now been corrected," he added.

Cautious technique

WHO's cautious approach to the outbreak, which has been challenged by a few critics, might be seen in the context of previous complaints about its continuous or too hasty use of the term, first used for the lethal 2009 H1N1 swine flu pandemic.

During the H1N1 outbreak, the UN health agency was criticized for sparking panic buying for vaccines with its pronouncement that the outbreak reached its pandemic proportions.

The health agency met severe grievances in 2014 for downplaying the severity of the Ebola epidemic in several West African countries. Ebola claimed more than 11,300 lives by the point it resulted in 2016.

WHO said understanding the time when infected patients may transmit the virus to others is critical for control efforts.

According to the health agency, detailed epidemiological information from more infected people is needed whether 2019-nCoV could occur from asymptomatic individuals or during the incubation period.