Singapore had been a master class in how to handle the Covid-19 outbreak. Before the disease even had a name, the country had stringent travel restrictions and an efficient contact-tracing operation which contained the virus's spread. But in recent days, the number of confirmed cases has rocketed. Thursday brought the highest day of new infections to date at 287, up from 142 the day before. Mostly, these are coming from densely-packed migrant worker accommodation. Having avoided it for months, Singapore is now under a partial lockdown, with schools and non-essential businesses closed, and people urged to stay at home. Experts say one of the world's wealthiest nations - which seemed to be doing everything right - has important lessons for poorer countries, and there's still time to put them in place. What was going well in Singapore? Singapore had its first case of the new coronavirus very early on. It was a Chinese tourist who arrived from Wuhan on 23 January, the same day the virus epicentre was put into a total lockdown. By the time the disease caused by the virus got its official name - Covid-19 - it was already spreading among the population here. But a well-rehearsed response was in place. In addition to health checks at airports, Singapore carried out extensive testing of every suspected case; tracked down anyone who'd come into contact with a confirmed case; and confined those contacts to their homes until they were cleared. WHO chief Tedros Adhanom Ghebreyesus called it "a good example of an all-of-government approach". For weeks, Singapore managed to keep its numbers low and trackable, with only small, easily contained clusters, without any real restrictions to daily life. But Prof Dale Fisher, chair of the WHO's Global Outbreak Alert and Response Network and a professor at the National University of Singapore, told the AFP that whenever he heard people say Singapore was doing well, he'd reply: "So far." "This is a really hard disease to contain," he says.