SINGAPORE - Although three Singapore residents and a foreign domestic worker here with no travel history to China have been infected by the coronavirus, it does not constitute widespread community transmission.
Health Minister Gan Kim Yong explained at a press conference on Tuesday (Feb 4) that this is because the source of infection for all four people is known.
Three were infected through interaction with a group from China - two members of whom are now known to have the coronavirus after returning to China - and the fourth person, the foreign domestic worker, through close contact with her employer who is one of the three.
The tour group is believed to be from Guangxi, a region in southern China, but Chinese authorities have yet to confirm this.
Two of the three infected women worked for Yong Thai Hang at 24 Cavan Road, a shop that sells complementary health products, and the third is the tour guide who took the group there.
So although it is community transmission, it is a limited transmission, he said. "For this particular cluster, we are able to identify all the contacts that are involved, including the source of the infection."
Mr Gan added: "If you have a cluster and you know who the first patient in that cluster is, but have no idea where he got the infection from, then we have a bigger problem."
But for this first local cluster, the Ministry of Health (MOH) has started contact tracing in order to ring-fence the cases so the coronavirus does not spread to more people.
"These efforts will help reduce the risk of escalation," said Mr Gan, adding that the Government has been expecting cases with limited community transmission like this one, and it is "a scenario we are prepared for".
He said measures will be ramped up "when you have cases popping up in different parts of Singapore and we are not able to determine the source, have no idea where they come from".
"As I pointed out (on Monday), despite our best efforts, Singapore could still see extensive community spread. At that point, we will need to consider measures to reduce human to human interactions, such as cancelling mass gatherings, suspending schools, paring down non-essential care services and introducing further infection control and monitoring measures, to slow the spread," he said.
This had happened during the Sars (severe acute respiratory syndrome) outbreak here in 2003.
"We're watching the situation very carefully, monitoring developments, and we're quite prepared to adjust our posture, our stance," Mr Gan said.
As to how the two saleswomen could have caught the virus from customers who were at the shop only to buy things, Mr Gan said there could be different modes of transmission - not just close contact that has been defined as within 2m for at least 30 minutes.
He said: "For example, a person who is ill might have been in contact with some of the merchandise. The merchandise could have been contaminated. The salesperson could have handled the material after that, and she touches her face, her eyes and nose, she could have got it. So it's not necessarily through talking or sneezing."
The MOH is still tracing where else the group had gone to and the hotel they stayed at, since the first of the four cases was confirmed only at 11pm on Monday night (Feb 3). The other three cases were confirmed on Tuesday.
Said Mr Gan: "We continue to be vigilant for more cases. There may be more with exposure to this particular travel group."