Case zero not always where first cluster is: WHO official

(Xinhua)    08:27, August 11, 2020

Dr. Michael Ryan(L), executive director of the World Health Organization (WHO) Health Emergencies Program, addresses a press conference, in Geneva, Switzerland, Feb. 18, 2020. (Photo by Chen Junxia/Xinhua)

Michael Ryan, executive director of the WHO Health Emergencies Program, has earlier said that although the first clusters of COVID-19 cases were reported in Wuhan of China, it doesn't necessarily mean that Wuhan is where the COVID-19 disease crossed from animals into humans.

GENEVA, 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, case zero is not always where the first cluster is.

Michael Ryan, executive director of the WHO Health Emergencies Program, said at a virtual press conference that case zero can be in another place, and "that's why we have to keep an open mind."

"All hypotheses are on the table, if you follow the data in the science, you will find, hopefully, the point at which the disease crossed the species barrier," 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, the United States, on April 24, 2020. (Photo by Michael Nagle/Xinhua)

According to the WHO official, this novel coronavirus is proving exceptionally difficult to stop -- "it's difficult to recognize, 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, Ryan explained to reporters that it took years to do it in the case of MERS, 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, because as long as the animal-human breach has not been discovered, there's always a chance that barrier can be breached again," he said.

Earlier this month at another press conference, Ryan also said that although the first clusters of COVID-19 cases were reported in Wuhan of China, it doesn't necessarily mean that Wuhan is where the COVID-19 disease crossed from animals into humans.

Wuhan is not necessarily the place where the COVID-19 disease crossed from animals into humans, said a senior WHO expert.

GENEVA, Aug. 3 (Xinhua) -- Although the first clusters of atypical pneumonia were reported in Wuhan, China, it doesn't necessarily mean that is where the COVID-19 disease crossed from animals into humans, a senior World Health Organization (WHO) expert said on Monday.

Dr. Michael Ryan, executive director of the WHO Health Emergencies Program, said at a routine COVID-19 briefing on Monday that a much more "extensive retrospective epidemiological study" should be taken to fully understand the links between the cases.



Senior students study in a classroom with transparent boards placed on each desk to separate each other as a precautionary measure against the spread of COVID-19 at Wuhan No. 23 Middle School in Wuhan, central China's Hubei Province, May 6, 2020. (Xinhua/Xiao Yijiu)

He stressed the need to start studies on the first reported human clusters in order to systematically look for the "first signal at which the animal-human species barrier was crossed," before moving to the studies on the animal side.

The WHO advance team that traveled to China in preparation for an international mission of identifying the zoonotic source of COVID-19 has concluded its mission recently, according to the WHO expert. Future studies will build on the initial investigations done by Chinese experts around the Wuhan seafood market.

Ryan also noted that WHO is moving forward with agreeing on the international team and ensuring that right expertise will be in place to work with the Chinese counterparts to design and implement further studies.