Singapore has recorded its first cases of local coronavirus transmission, with four women who had not travelled to Wuhan, the epicentre of the outbreak, getting infected here.
Two work at Yong Thai Hang, a Chinese health products shop in Cavan Road in Lavender which caters to Chinese tour groups.
The third is employed as a maid by one of the infected women, while the fourth is a tour guide who had taken groups to the same shop.
The tourists have since returned to China. At least two have the virus.
In addition, another two confirmed cases in Singapore were announced yesterday. The two Singaporeans were among a group of 92 people flown back from Wuhan on a Scoot flight last Thursday. Before this, the infection was confirmed in two passengers on that flight.
In total, there are now 24 confirmed cases in Singapore.
The new cases constitute "limited local transmission", the Health Ministry (MOH) said.
But Health Minister Gan Kim Yong said at a press conference: "There is, however, no evidence of widespread community transmission."
Singapore has put in place multiple lines of defence to prevent the virus from taking hold here. But Mr Gan, who co-heads a multi-ministry task force set up to combat the virus, cautioned that "despite our best efforts, Singapore could still see extensive community spread".
Should that happen, additional measures to reduce human-to-human interactions will be considered, such as cancelling mass gatherings, suspending school and paring down non-essential care services.
The country has been preparing for such clusters of cases, and efforts so far have been targeted at preventing the spread beyond such local clusters to the broader community. MOH has started contact tracing so as to ringfence the cluster and limit further spread.
The cleaning of public areas is being stepped up, and measures are being taken to lower the risk for vulnerable groups such as young children and the elderly.
To keep students safe, for instance, schools will implement staggered recess times and stop activities such as mass assemblies and school camps. Eldercare facilities will also suspend excursions and large-scale gatherings.
As an added precaution, the authorities are contacting people with profiles similar to the four local transmission cases, who have had recent close contact with individuals with a history of travel to China.
In addition, all patients with pneumonia at public hospitals are being tested for the 2019-nCoV, as the virus is called, starting last week.
Current evidence suggests the virus can be spread by droplets from infected individuals - either directly or indirectly through hands that have come into contact with the droplets - and the best way to prevent this is through personal hygiene, said MOH. Businesses and organisations are also advised to clean their premises more often, especially high-traffic areas.
The earlier 18 confirmed cases of the virus here were all imported, comprising 16 Chinese nationals and two Singaporeans who had all travelled to Wuhan. One, a Chinese national, has been discharged, said the ministry yesterday.
The update was given after a two-day lull on Sunday and Monday, when no new cases were reported.
The coronavirus has infected more than 20,000 people and claimed over 420 lives, mainly in China. The global authorities have warned of more person-to-person spread, with several countries reporting local transmission.
• Additional reporting by Timothy Goh