Coloured scanning electron micrograph (SEM) of SARS-CoV-2 coronavirus particles (blue) emerging from the surface of cells isolated from a US case of the disease Covid-19. SARS-CoV-2 (previously 2019-nCoV) was first identified in Wuhan, China, in December 2019. It is an enveloped RNA (ribonucleic acid) virus. The coronaviruses take their name from their crown (corona) of surface proteins, which are used to attach and penetrate their host cells. Covid-19 is a respiratory infection that can lead to fatal pneumonia. As of the 25th February 2020, over 80, 000 have been infected worldwide with over 2, 500 deaths. Travel restrictions and infection control measures have been put in place to slow the spread of the virus.