The 2019 Novel Wuhan Coronavirus (2019-nCoV) epidemic (namely COVID 19) was first reported and confirmed on 31 December 2019, in Wuhan, Hubei Province, China, which is one of China’s largest cities and a major domestic transport hub. The epidemic is attracting worldwide concern due to its rapid spread and transmission rate between humans. On 30 January 2020, the International Health Regulations, Emergency Committee of the World Health Organization (WHO) declared the outbreak – a ‘public health emergency of international concern’. On 8 February 2020 (24:00 GMTþ۸), there were 37,198 confirmed infections in China (including 811 deaths with a death ratio of 2.1%; and 6188 patients were confirmed in serious condition and 28,942 suspected cases). The COVID 19 infections were also reported in 26 other countries on 7 February 2020, including Canada, the USA, Australia, India, Sri-Lanka, Cambodia, Thailand, Vietnam, Malaysia, Singapore, Taiwan, the Republic of Korea, SriLanka, Japan, Philippines, Nepal, United ArabEmirates, Russia, Italy, Germany, Sweden, Finland, Belgium, Spain, France and the UK. The coronavirus outbreak reminds us of the many feared and uncertainties that were reported at the peak of the severe acute respiratory syndrome (SARS) crisis in 2003 and some guidance for transmission prevention have been published.5–۸ An estimate of the virus’ negative economic impact shows a decline of one percentage point in the growth rate of the Chinese Gross Domestic Product (GDP) in the first quarter of 2020. The rapid spread of the infection and the high level of morbidity associated with the COVID 19 epidemic is calling for a rapid and strict implementation of the appropriate control measure. The risk from the outbreak depends on whether and how well the virus are spread between people. The outbreaks of the severe virus infection in past decades are all very closely related to the transmission between person to person in indoor environment, such as the 2003 SARS epidemic, the 2009 H1N1 influenza pandemic and the 2014 Middle East respiratory syndrome (MERS) epidemic.