Mutating coronavirus. Illustration of a mutated form of a coronavirus (blue) exiting a cell. It has mutated from the red form of the virus. Mutations can allow a virus to infect a species that it was unable to infect before, such as an animal virus becoming able to infect humans, or change its virulence, so that it causes a more deadly disease. It is thought that the SARS-CoV-2 (previously 2019-nCoV), which was first identified in Wuhan, China, in December 2019, mutated from an animal virus. It causes a respiratory infection (Covid-19) that can lead to fatal pneumonia. As of mid February 2020, over 46, 000 have been infected in China with over 1, 300 deaths. There have been over 440 confirmed cases outside of China, with one death. In China travel restrictions and infection control measures have been put in place to slow the spread of the virus.