The novel coronavirus epidemic that started in Wuhan, china on December 8, 2019, has infected more people than the severe acute respiratory syndrome coronavirus (Sars-Cov) and the Middle East respiratory syndrome coronavirus (Mers-Cov) combined.
World Health Organization (WHO) of the United Nations declared the epidemic a public health emergency of international concern. This defines the outbreak an “extraordinary event which is determined to constitute a public health risk to other States through the international spread of disease and to potentially require a coordinated international response”. Several countries and airlines immediately suspended travel from affected areas, closed some borders with China, and initiated comprehensive preventative screening at airports.Early on, the Chinese authorities revealed that the outbreak was caused by a novel beta-coronavirus, named 2019-nCoV. This was soon found to be significantly genetically related to Sars-Cov and other bat coronaviruses. The initial cases were associated with a seafood market in Wuhan where live animals were sold. This suggested a possible animal reservoir for this virus and suggested zoonotic (animal to human) transmission. Later on, environmental samples obtained from this market were found to be positive for 2019-nCoV, strengthening the hypothesis that this is a zoonotic virus. However, whilst the virus was found to have originally started among infected animals, most of the subsequently reported cases were shown to be caused by human-to-human transmission.
Sars-Cov was discovered in China before being spread globally, infecting 8,098 people and killing 774. This was later found to be zoonotic in origin and thought to have started amongst a bat reservoir before later infecting wild civet cats and raccoon dogs that were being sold at live wild animal markets destined for human consumption. In 2012, Mers-Cov was discovered in Saudi Arabia before also spreading globally resulting in 2506 confirmed cases and killing 862 people worldwide. Again, this started as a zoonotic virus, shown to move from camels to humans and again thought to have initially emerged from bats.
When MERS was discovered, a group of witty scientists led by Dutch investigators were able to associate the new virus with camels by showing that archived camel sera had antibodies against this new virus. This group deserved to earn the scientific scoop but did the right thing by alerting other coronavirus researchers about their findings even before their paper was published. Taking this hint, my group started sampling camels and verified that camels indeed have antibodies against Mers-Cov in collaboration with researchers from Hong Kong University. Later on, we were able to isolate Mers-Cov from camels. Determining the animal reservoir allowed the identification of people exposed to camels as an at-risk population and allowed targeted public health prevention campaigns. The animal reservoir for 2019-nCoV is yet to be determined.