As countries close borders, shut shops and schools and cancel big events, some of us are pondering whether the hysteria around coronavirus is overdone, whether governments really need to take drastic steps that are effectively plunging much of the globe into financial hardship. This is a world we have never seen and one which has been described, by UK health secretary Matt Hancock, as the biggest test for Britain since World War II. President Cyril Ramaphosa has declared the spread of Covid-19 as a "national disaster" for South Africa, warning that there will be additional economic challenges ahead for the country. In a glimmer of hope that the invisible scourge of coronavirus can be overcome, the rate of infection has stabilised in China and the price of steel bars is up in Shanghai on expectations that Beijing will stimulate the Chinese economy. The Wall Street Journal has set out a very thorough fact sheet of exactly what the experts know so far about the disease, from how it infects humans to how to prevent catching the ugly virus. – Jackie Cameron