Genetics of the new Conoravirus – Coronaviruses are a group of viruses that cause diseases in mammals and birds. In people, human coronaviruses cause respiratory infections, including the common cold. But some strains, such as the newly identified coronavirus in Wuhan, China, and the ones that cause Middle East Respiratory Syndrome (MERS) and Severe Acute Respiratory Syndrome (SARS), can be deadly.
The coronavirus family tree
The exact origin of the new coronavirus is yet to be confirmed but researchers analysing its genetic material say bat coronaviruses are its closest relative. The GISAID Initiative, a platform promoting the international sharing of virus data, states that the genome is 80% identical to the SARS virus but further away from the MERS virus.
Making the jump to humans
Coronaviruses are zoonotic, meaning they can pass from animals to humans. Investigations found that the virus that caused SARS probably originated in bats and passed through civet cats and the virus that causes MERS probably came from bats to camels to humans.
Animal viruses can mutate or combine with other viruses to create new strains capable of being passed to people. With the new coronavirus, it is unclear whether it was passed from bats to humans or if it passed via an intermediary species. Some scientists say the new coronavirus is the result of viral recombination – a process where more than one virus infects the same cell at the same time and creates a ‘recombinant’ virus strain.
Genetics of the new Conoravirus – Transmission
There is good evidence to show the new coronavirus can now be transmitted from person-to-person. A virus survives by finding a host and using its living cells in which to replicate, or to have itself reproduced. When a virus invades a host, it enters its cells and hijacks the cell’s natural production systems to make new copies of itself. The replication process can result in tiny mistakes or changes in the new viruses produced, leading to the virus mutating.
Data from the GISAID Initiative shows evolutionary relationships of viruses from the new coronavirus outbreak. Clustering of related infections can be seen. These are noted by GISAID as “family cluster infection”, representing direct human-to-human transmission.
Evolution of the virus
Genetic relationship between 33 samples taken.
Data as of Jan. 29.
The virus has caused alarm because it is still too early to know how dangerous it is and how easily it spreads among people. Chinese officials say it is infectious during its incubation period, which could range from one to 14 days.