From severe acute respiratory syndrome-associated coronavirus to 2019 novel coronavirus outbreak:similarities in the early epidemics and prediction of future trends

Emerging infectious diseases represent a serious threat for human public health worldwide.[1,2]The 2019 novel coronavirus(2019-nCoV)caused a pneumonia outbreak,which is spreading around the country and has affected 32 provinces and regions of China as of January 27,2020.[3,4]Countries outside China,including Japan,the United States,Thailand,and South Korea,have also reported cases imported from other countries.[5]With the joint efforts of Chinese scientists,health workers,and related departments,the pathogen causing this epidemic was quickly identified as a new type of coronavirus,10 days after the first official report.After confirming the pathogen,specific detection methods were rapidly developed,with improvement in etiological diagnosis.As of January 22,2020,it has been confirmed that the new coronavirus came from wild bats and belonged to group 2b of the beta coronavirus,which includes severe acute respiratory syndrome-associated coronavirus(SARS-CoV).[6]Although 2019-nCoV and SARS-CoV belong to the same sub-group of beta coronaviruses,the similarity at the genome level is only 80%,[7,8]meaning that the new virus is genetically different from SARS-CoV[Supplementary Figure 1A,http://links.lww.com/CM9/A209].Rapid discovery of the causative agent and development of diagnostic reagents demonstrated that technology has greatly improved in the 17 years since the SARS outbreak.However,no effective anti-viral medication or vaccines are available for this new virus,and many of its aspects remain to be explored.Similar to the SARS outbreak,this outbreak also occurred during the spring festival,the most important of the Chinese traditional festivals,when 3 billion people travel throughout the country.[9]This unexpectedly provides beneficial conditions for the transmission of this highly infectious disease and correspondingly poses great challenges for the prevention and control of the outbreak.