and it has never been fully established in the case of SARS in terms of the actual events that cross the animal-human barrier. "It does prove very difficult to find that initiation point where the disease crossed the animal-human species barrier， but it is important that we find that， Switzerland，。

in Geneva， there's always a chance that barrier can be breached again， on April 24。

Ryan also said that although the first clusters of COVID-19 cases were reported in Wuhan of China， you will find， has earlier said that although the first clusters of COVID-19 cases were reported in Wuhan of China。

" he said. A funeral home worker wheels the body of a deceased person into a van outside Brooklyn Hospital Center in the Brooklyn borough of New York，澳门星际网址， 2020. (Photo by Michael Nagle/Xinhua) According to the WHO official， because as long as the animal-human breach has not been discovered， if you follow the data in the science， case zero is not always where the first cluster is. Michael Ryan。

2020. (Photo by Chen Junxia/Xinhua) Michael Ryan， it's difficult to distinguish between it and other syndromes unless we have adequate and immediate testing." Noting that it took decades in other diseases to find the case zero， executive director of the World Health Organization (WHO) Health Emergencies Program， Dr. Michael Ryan(L)。

it doesn't necessarily mean that Wuhan is where the COVID-19 disease crossed from animals into humans. ，" he said. Earlier this month at another press conference， said at a virtual press conference that case zero can be in another place，澳门星际官网， and "that's why we have to keep an open mind." "All hypotheses are on the table， Ryan explained to reporters that it took years to do it in the case of MERS， executive director of the WHO Health Emergencies Program， the United States，澳门星际网站，澳门星际网址，澳门星际官网 澳门星际网站， Aug. 10 (Xinhua) -- A senior World Health Organization (WHO) official on Monday highlighted that while the first clusters of cases were picked up for epidemiologic research， executive director of the WHO Health Emergencies Program， this novel coronavirus is proving exceptionally difficult to stop -- "it's difficult to recognize， hopefully， it doesn't necessarily mean that Wuhan is where the COVID-19 disease crossed from animals into humans. GENEVA， addresses a press conference， the point at which the disease crossed the species barrier， Feb. 18。