Coloured scanning electron micrograph (SEM) of SARS-CoV-2 coronavirus particles (yellow) on an apoptotic cell (red) from a US patient sample. SARS-CoV-2 (previously 2019-nCoV) was first identified in Wuhan, China, in December 2019, and has been declared a pandemic. It is an enveloped RNA (ribonucleic acid) virus. It causes Covid-19, a respiratory infection that can lead to fatal pneumonia. As of mid April 2020, over 1.8 million have been infected worldwide with over 117,000 deaths. Social restrictions and infection control measures have been put in place to slow the spread of the virus.