US states also show very different trajectories. Washington saw the first outbreak in the US, but its death toll has risen relatively slowly since then. New York’s mortality curve is much steeper.

In most western countries case numbers have been increasing by about 33 per cent a day, a sign that other countries may soon be facing the same challenge as Italy.

The Asian city-state of Singapore and the territory of Hong Kong are on a different trajectory in terms of the growth in case numbers. The rate of increase has so far been relatively contained through rapid and strict measures.