The two closest known relatives SARS2 virus collected bats living caves Yunnan , province southern China.If SARS2 virus first infected people living around Yunnan caves , would strongly support idea virus spilled people naturally.But ’ happened.The pandemic broke 1,500 kilometers away , Wuhan.Beta-coronaviruses , family bat viruses SARS2 belongs , infect horseshoe bat Rhinolophus affinis , ranges across southern China.The bats ’ range 50 kilometers , ’ unlikely made Wuhan.In case , first cases COVID-19 pandemic probably occurred September , temperatures Hubei province already cold enough send bats hibernation.What bat viruses infected intermediate host first ? You would need longstanding population bats frequent proximity intermediate host , turn must often cross paths people.All exchanges virus must take place somewhere outside Wuhan , busy metropolis far known natural habitat Rhinolophus bat colonies .