#WHOChina presser. Understanding the process of spill over requires a detailed investigation. Interaction animals, humans and environment. Then established h2h transmission. A virus causing global pandemic must be adaptive can occur through multiple steps. https://twitter.com/gail_carson/status/1359073202731962372

SARSCoV2 may have originated from zoonotic transmission with animal hosts yet to be identified. The second phase inc evolution in humans. Spillovers may occur repeatedly. Early spillovers may go undetected. Then see clusters in different geographical groups. Result pandemic.

Evidence studies have shown other CoVs in bats and pangolins might be a reservoir for COVID. However, the viruses ID so far from these species are NOT sufficiently similar. In addition, comparison other potential reservoirs under sampled. Wuhan data before Dec 31 2019.

suggests a cluster, however, sequence data some diversity of the virus already. Lit review of the data early circulation from unpub. studies from different countries preceding initial detection by several weeks. This indicates missed reported circulation in other regions.

Keen to hear what @MarionKoopmans says and for a written summary of this presser as listening live via a translator.

ILI and SARI surveillance with lab confirmation is used for resp viruses. Wuhan hospital for ILI, & SARI provincial findings NO substantial unrecognised circulation of SARSCoV2 in Wuhan at end of 2019.

Samples taken second half of 2019 Wuhan retrospectively looked for SARSCoV2 in over 4000 - no SARS CoV 2 found.

Little evidence of fluctuation in mortality in Wuhan to suggest earlier circulation of SARS CoV2. There is no indication of circulation in the population before Dec 2019. Searched 76,000 episodes one of 4 presenting symptoms Oct 1 - Dec 10 2019 - also tested for antibodies.

None compatible with SARS-CoV2 infection. Retrospective search in Wuhan has not found clear evidence of clinical presentation of SARSCoV2 - unlikely SARSCoV2 circulation occurring in Wuhan 2 months prior.

Substantial transmission occurred in Wuhan in Dec 2019. Most cases reported second half of Dec. Many associated with the market. Transmission also elsewhere in Wuhan at the same time. It is not possible to say how intro into the market. While some early cases assoc with market

Other cases at other markets and elsewhere same time. This is the team's judgement on the current info. Cannot say how SARSCoV2 was intro into the market.

CoVs phylogenetically ID in different animals - horse shoe bats and pangolins. Regarding the Huanan market - intro of the virus through people, animals or animal products as multiple surfaces contaminated.

In China a link to the cold chain of food. Indicate travel on cold chain products. Needs further study. In Huanan market cases can be mapped to certain stores. Speaker concludes his Intro to major findings.

@WHO Peter Embarek - now speaks. We recognise the impact on the city of Wuhan of the pandemic. Thank you. Have heard the many findings. A detailed report to follow.

2 goals - 1. try to get better understanding of what happened Dec 2019 & 2 How did the virus emerge and jump into human population.

Dec 2019 - did we change the picture we had before? No. Did we improve our understanding ? Yes. You have heard some of the key findings already.

In trying to understand in Dec 2019, tried to find missed cases, conc: we did NOT find evidence of large outbreaks that could be related prior to Dec 2019.

Evidence of wider circulation in Dec not just the cluster in the Huanan market but also, outside of the market. The pic we see is a classical pic of an emerging outbreak - few sporadic cases in Dec then, small outbreaks starts to spread in clusters in Huanan market.

These early clusters the way one detects the first cases of an emerging disease and this is what happened in Dec 2019. When mapping all the initial cases combining with location and mapping of some of them in the market with genetic seq from some - we could see that pic clearer

of spread within and outside the market as move into Jan 2020. Dates and info we got from the retrospective search inc mortality and surv data etc, reanalysing gen sequences all these data fit with the picture just described.

Tried to understand how the virus came into Wuhan. All the work done on the virus and to ID it's origin point towards a natural reservoir in bat population. Since Wuhan is not close to bat environments, a direct jump is not very likely. Tried to find other animal species.

That could have potentially intro the virus into the market. The market dealt primarily with frozen animal products; seafood and products from domesticated wildlife. The joint team in their studies have ID the vendors trading, ID suppliers, ID farms - different parts China.

And some imported. Overall, important to continue the follow up with those identified through these studies. Large amount of testing in different species throughout China; domestic, farmed and wild - NOT possible to pinpoint any reservoir.

Does not look like there was wide circulation in any animal species in the country. The search for the possible introduction and reservoir is still a work in progress. Next step - look at the future. Exercise ID 4 main hypotheses of intro of virus to humans.

Used all collected info. from past 4 weeks and literature. 1 Direct zoonotic spillover. 2. intermed host animal where virus can adapt 3. Frozen products 4. Lab related incident. *The intro. through intermed. host is the most likely* Need more research. 3 also needs more research