Illustration of coronaviruses, the cause of the new disease covid-19. This disease was first detected in Wuhan, China, in December 2019. It is contagious and has since spread rapidly around the world. The disease causes fever, cough and shortness of breath, and can lead to fatal pneumonia in some cases. SARS-CoV-2 is an RNA virus that uses protein spikes to gain entry to host cells.