On 12 January – less than three months ago – the coronavirus was confined to China. Not a single case had been found outside the country where it emerged.
And then, on 13 January, the virus became a global problem. A case was recorded in Thailand before Japan, South Korea and the United States soon followed.
Across the world, a trickle of cases became a flood.
There have now been more than a million Covid-19 cases worldwide, in countries from Nepal to Nicaragua. But as the death tolls rise, and the hospitals overflow, is anywhere still coronavirus-free?
The answer, perhaps surprisingly, is yes.
There are 193 countries which are members of the United Nations.
As of 2 April, 18 countries had not reported a Covid-19 case, according to a BBC tally using data from Johns Hopkins University.
The 18 countries without Covid-19
Comoros; Kiribati; Lesotho; Marshall Islands; Micronesia; Nauru; North Korea; Palau; Samoa; Sao Tome and Principe; Solomon Islands; South Sudan; Tajikistan; Tonga; Turkmenistan; Tuvalu; Vanuatu, Yemen
Some, experts agree, are likely to have unreported cases. North Korea, for example, is officially on zero, as is war-torn Yemen.
But there are countries where the virus has not landed. Most are small islands with few visitors – in fact, seven of the world’s 10 least-visited places, as per UN data, are free of Covid-19.
That remoteness means one thing: in this age of social-distancing rules, island nations are the original self-isolators.
But the president of one such place is not complacent. In fact, he tells the BBC, Covid-19 is already a national emergency.
Nauru, in the Pacific Ocean, is almost 200 miles (320km) from anywhere – Banaba Island, part of Kiribati, is the nearest land. The nearest “major” city with direct flights is Brisbane, 2,500 miles south-west.
It is the second-smallest UN state in terms of land (after Monaco) and, with just over 10,000 people, the second-smallest in terms of population (after Tuvalu).
It is also one of the least-visited places on Earth. Although it does not appear in the most recent UN data, one tour operator says the country has just 160 tourists a year.
You may think such a distant place would not need to distance itself further. But a country with one hospital, no ventilators, and a