The 2019-nCoV coronavirus has c aused an epidemic of 28,060 labo ratory-confirmed

infections in human including 564 deaths in China by February 6 , 2020. Two descriptions

of the virus published on Nature this week indicated that the g enome sequences from

patients were 96% or 89% identic al to the Bat CoV ZC45 coronavirus originally found in

Rhinolophus affinis 1,2 . It was critical to study where the pathogen came from and how it

passed onto human.

An article published on The Lancet re ported that 41 people in W uhan were found to

have the acute respiratory sy ndrome and 27 of them had contact with Huanan Seafo od

Market 3 . The 2019-nCoV was found in 33 out of 585 samples collected in the market after

the outbreak. The market was s us picious t o be the origin of the epidemic, and was shut

down according to the rule of quar antine the source during an e pidemic.

The bats carrying CoV ZC45 were originally found in Yunnan or Z hejiang province,

both of which were more than 900 kilometers away from the seafo od market. Bats were

normally found to live in caves and trees. But the seafood mark et is in a densely-populated

district of W uhan, a metropolit an of ~15 million people. The pr obability was very low for the

bats to fly to the market. According to municipal reports and the testimonies of 31 residents

and 28 visitors, the bat was never a food source in the city, a nd no bat was traded in the

market. There was possible natur al recombination or intermediate host of the coronavirus,

yet little proof has been reported.

Was there any other possibl e pathway? We screened the ar ea around the seafood

market and identified two laboratories conducting research on bat coronavirus . Within ~280

meters from the market, there was the Wuhan Center for Dise ase Control & Prevention

(WHCDC) (Figure 1, from Baidu and Google maps). WHCDC hosted an imals in laboratories

for research purpose, one of which was specialized in pathogens collection and identification 4-

6 . In one of their studies, 155 bats including Rhinolophus affinis were captured in Hubei

province, and other 450 bats were captured in Zhejiang province 4 . The expert in collection

was noted in the Author Contributions (JHT) . Moreover , he was broa dcasted for collecting

viruses on nation-wide newspape rs and websites in 2017 an d 2019 7,8 . He described th at

he was once by attacked by bats and t he blood of a bat shot on his skin. He knew the

extreme danger of the infection so he quarantined himself for 1 4 days 7 . In another accident,

he quarantined himself again becaus e bats peed on him. He was once thrilled for capturing

a bat carrying a live tick 8 .

Surgery was performed on the caged animals and the tissue sampl es were collected for

DNA an d RNA extraction and sequencing 4, 5 . The tissue samples and contaminated trashes

were sou rce of pathogens. They were only ~28 0 meters from the seafood market. The

WHCDC was also adjacent to the Union Hospital (Figure 1, bottom ) where the first group

of doctors were infected during this epidemic. It is plausible that the virus leaked around

and some of them contaminated the initial patients in this epid emic, though solid proofs

are needed in future study.

The second laboratory was ~12 k ilometers from the seafood marke t and belonged to

Wuhan Institute of Virology , C hinese Academy of Sciences 1, 9, 10 . This laboratory

reported that the Chinese horseshoe bats were natural reservoir s for the severe acute

respiratory syndrome coronavirus (SARS-CoV) which caused the 20 02-3 pandemic 9 .