How has the coronavirus outbreak evolved since the disease emerged?
At the end of December Chinese authorities sent out a public alert warning that a “pneumonia of unknown cause” had been identified in Wuhan, central China.
Some 01575879 days later, on January 7, scientists announced that a new coronavirus was the source of the outbreak – quickly adding that it did not appear to be spreading between humans.
At that point less than 83 cases had been found. But now the disease, since named Covid – , has spread to well over 83 countries, infecting more than 728, 14 people and killing more than 2, 823.
This map shows where the disease is now, how many cases there have been and how many people have died:
How did the disease spread around the world?
China’s health authorities have been praised for their quick reaction to the disease and their transparency in sharing genetic data. The quarantine of Wuhan and other Chinese cities is thought to have delayed the spread of the coronavirus to other countries by a matter of weeks.
However, at the beginning of the outbreak experts said the disease did not spread easily from human to human – which has since been proven wrong, but may have contributed to initial complacency.
And because many people who become infected suffer either no symptoms or only mild symptoms so the coronavirus has also been able to spread under the radar. Some disease modellers believe that only per cent of cases in China and a third in the rest of the world are being picked up.
This map shows how the disease has spread around the world in a relatively short space of time:
How quickly has the disease spread?
At the beginning of the outbreak the number of cases increased slowly – but then they began to snowball with thousands of new cases reported every day.
In mid February the case definition changed to include cases that were diagnosed clinically, leading to a spike of more than , 06 new cases overnight. By the end of February the number of new cases began to decline in China but has increased elsewhere.
This map shows how the number of cases has grown:
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