Contact tracing continued in Singapore as the Republic confirmed two more imported cases of the Wuhan virus yesterday.
As of noon yesterday, the Ministry of Health (MOH) had identified 46 close contacts of the first confirmed case, a 66-year-old man, 24 of whom had left Singapore.
Of the remainder, one was identified as Singapore's third confirmed case and isolated, 16 were quarantined, and efforts are ongoing to contact the remaining five.
The drivers of the taxi and chartered car the 66-year-old man was in have also been identified.
The second confirmed case, a 53-year-old Chinese tourist from Wuhan, had stayed at J8 hotel and taken public transport and a taxi to places including Orchard Road, Marina Bay Sands and Gardens by the Bay.
The authorities say there is no need for alarm. Associate Professor Vernon Lee, director of Communicable Diseases at MOH, said there are three categories of contacts that may have encountered the patients.
In the first tier, close contacts, are those who were in close proximity - about 2m - to the patient, and spent about 30 minutes or more with them. "These would typically be family members, travelling companions - they would be at higher risk of exposure," said Prof Lee, adding that they would be quarantined.
In the second tier are moderate-risk contacts, who may have come into contact with the patient but were not in close proximity or for a prolonged period - for instance, someone who encountered the patient at a check-in counter.
This group would be put under phone surveillance, meaning they are reminded to monitor their health, and receive daily calls for 14 days since their last exposure to the patient to ensure they are well.
"If they are not feeling well at any point in time, we advise them to put on a mask and see a doctor," said Prof Lee.
In the final tier, transient contacts, are those who walked past the person on public transport or in public places. "We would assess the risk to be low, and not do any specific measures regarding them," said Prof Lee. However, everyone should practise good individual hygiene and see a doctor if ill.
The authorities are carrying out contact tracing to find out what exactly the 53-year-old did in the places she visited. They are also trying to get more information on the additional contacts and movements of the third patient.
3 confirmed cases of Wuhan virus
Man, 66, from China
• Singapore's first Wuhan virus case confirmed on Jan 23
• Warded at Singapore General Hospital (SGH) in Outram
• In stable condition
• Landed on Jan 20 on China Southern Airlines flight CZ351 from Guangzhou at 10.40pm
• Travelled in a party of 10, including his 37-year-old son
• Stayed at Shangri-La's Rasa Sentosa Resort & Spa
Woman, 53, from China
• Confirmed on Jan 23 midnight
• Warded at the National Centre for Infectious Diseases in Novena
•In stable condition
• Landed on Jan 21 on Scoot flight TR121 from Wuhan at 5.30am
• Travelled with a companion
• Stayed at J8 Hotel near Lavender MRT station
• Visited Orchard, Marina Bay Sands and Gardens by the Bay
Man, 37, from China
•Confirmed on Jan 24
•Warded at SGH
•In stable condition
•Son of the 66-year-old man who is Singapore's first Wuhan virus patient
Aw Cheng Wei