Coloured 3D computed tomography (CT) scan (posterior view) of human lungs that are recovering from Covid-19 atypical pneumonia. Areas of scar tissue (red and orange) are seen. Covid-19 is a respiratory infection that can lead to fatal pneumonia. It is caused by the coronavirus SARS-CoV-2 (previously 2019-nCoV), which was first identified in Wuhan, China, in December 2019. As of early April 2020, over 1.1 million have been infected worldwide with over 62,000 deaths. Social restrictions and infection control measures have been put in place to slow the spread of the virus.