The possible origins of 2019-nCoV coronavirus 
Botao Xiao1,2* and Lei Xiao3 
1 Joint International Research Laboratory of Synthetic Biology and Medicine, School 
of Biology and Biological Engineering, South China University of Technology, 
Guangzhou 510006, China
2 School of Physics, Huazhong University of Science and Technology, Wuhan 
430074, China
3 Tian You Hospital, Wuhan University of Science and Technology, Wuhan 430064, 
China
* Corresponding author: xiaob@scut.edu.cn
Tel / Fax: 86-20-3938-0631
The 2019-nCoV coronavirus has caused an epidemic of 28,060 laboratory-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  genome  sequences  from 
patients were  96%  or 89% identical 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 reported that 41 people in Wuhan were found  to 
have the acute respiratory syndrome and 27 of them  had  contact  with  Huanan  Seafood 
Market 3. The 2019-nCoV was found in 33 out of 585 samples collected in the market after 
the outbreak. The market was suspicious to be  the origin of the epidemic, and  was  shut 
down according to the rule of quarantine the source during an epidemic. 
The bats carrying  CoV  ZC45  were originally  found  in Yunnan or Zhejiang province, 
both of  which were more than 900 kilometers away  from  the seafood market. Bats were 
normally found to live in caves and trees. But the seafood market is in a densely-populated 
district of Wuhan, a metropolitan of ~15 million people. The probability 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, and no bat was traded in the 
market. There was possible natural recombination or intermediate host of the coronavirus, 
yet little proof has been reported.
Was there  any  other  possible  pathway?  We  screened the  area  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 Disease Control &  Prevention 
(WHCDC) (Figure  1,  from Baidu and Google maps).  WHCDC hosted animals 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 broadcasted for collecting 
viruses on nation-wide newspapers and websites in 2017 and 2019 7,8. He described that 
he was once  by  attacked  by  bats and  the blood of  a  bat  shot on  his skin.  He  knew  the
extreme danger of the infection so he quarantined himself for 14 days 7. In another accident, 
he quarantined himself again because 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 samples were collected for 
DNA and RNA extraction and sequencing 4, 5. The tissue samples and contaminated trashes 
were  source  of pathogens. They  were  only  ~280  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  epidemic,  though  solid  proofs 
are needed in future study.  
The second laboratory was ~12 kilometers from the seafood market and belonged to 
Wuhan Institute of Virology, Chinese Academy of Sciences 1, 9, 10. This laboratory 
reported that the Chinese horseshoe bats were natural reservoirs for the severe acute 
respiratory syndrome coronavirus (SARS-CoV) which caused the 2002-3 pandemic 9. 
The principle investigator participated in a project which generated a chimeric virus using 
the SARS-CoV reverse genetics system, and reported the potential for human 
emergence 10. A direct speculation was that SARS-CoV or its derivative might leak from 
the laboratory.
In summary, somebody was entangled with the evolution of 2019-nCoV coronavirus. 
In addition to origins of natural recombination and intermediate host, the killer coronavirus 
probably originated from a laboratory in Wuhan. Safety level may need to be reinforced in 
high  risk  biohazardous  laboratories.  Regulations  may  be  taken  to  relocate  these 
laboratories far away from city center and other densely populated places. 
Contributors
BX designed the comment and performed literature search. All authors performed data 
acquisition and analysis, collected documents, draw the figure, and wrote the papers. 
Acknowledgements
This work is supported by the National Natural Science Foundation of China (11772133, 
11372116).
Declaration of interests
All authors declare no competing interests.
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