In Singapore, one of the first places hit by coronavirus, detectives are tracking down potential positive cases to try to stay one step ahead of the virus. How did they do this and is it too late for the rest of the world?
In mid-January, a group of 20 tourists from the Chinese city of Guangxi arrived in Singapore for Chinese New Year. They visited some of its most glamorous sights.
Also on their itinerary was a non-descript traditional Chinese medicine shop, selling crocodile oil and herbal products. The shop is popular with mainland tourists.
They were served by a dedicated saleswoman who showed them various products, even massaging medicated oil on their arms. The Chinese group finished the tour and went home.
But they had left something behind.
At that point, the 18 coronavirus cases in Singapore had only been found in arrivals from mainland China.
But on 4 February, Singapore's government reported that the virus had spread into the local community - and the Yong Thai Hang Chinese medicine shop was its first cluster, with a local tour guide and that enthusiastic saleswoman falling ill.
From that one shopping trip, nine people became infected, including the saleswoman's husband, her six-month-old baby and their Indonesian domestic helper. Two other staff members also caught it.
They have now recovered, but it could have been much worse if Singapore didn't have a sophisticated and extensive contact tracing programme, which follows the chain of the virus from one person to the next, identifying and isolating those people - and all their close contacts - before they can spread the virus further.
"We would have ended up like Wuhan," says Leong Hoe Nam, an infectious diseases specialist at the Mount Elizabeth Novena hospital and a Singapore government advisor.
"The hospitals would be overwhelmed."
|In total, 6,000 people have been contact traced |
As of 16 March, Singapore had confirmed 243 cases and no deaths. For about 40% of those people, the first indication they had was the health ministry telling them they needed to be tested and isolated.
In total, 6,000 people have been contact traced to date, using a combination of CCTV footage, police investigation and old fashioned, labour-intensive detective work - which often starts with a simple telephone call.