SINGAPORE: COVID-19 transmission at the Bukit Merah View cluster could have taken place through long queues and surfaces in toilets, the Ministry of Health (MOH) said on Friday (Jun 18).
"There could have been also an element of fomite transmission through the use of common facilities, including the toilets," said MOH's director of medical services Kenneth Mak.
Fomite transmission refers to the transmission of infectious diseases by germs left on objects.
"For visitors at the market and food centre - this could also have been a contributory (factor) - but we know that a number of the stalls at the food centre are very popular lunch and dinner destinations," said Associate Professor Mak.
"And there are many who work in the vicinity, who will visit both the market and the food centre for their meals. And some of the cases that we have interviewed have reported queuing up for at least 30 minutes, which would ordinarily be considered a significant period of close contact if these visitors were close together."
This comes after MOH on Thursday reported 17 new cases linked to Bukit Merah View cluster, bringing its total to 56 cases.
Of the 56, 21 are tenants, stallholders or staff who work at the market or food centre, while 13 are visitors to the market or food centre, Assoc Prof Mak said on Friday at a press conference held by the COVID-19 multi-ministry task force.
The remaining cases are "next generation of transmission" cases involving those who did not visit the market or food centre but had close contact with other cases who visited the places or worked there, he said.
Fifty per cent of the 56 cases are unvaccinated, 32 per cent are fully vaccinated, while the rest have received one jab or have not got full protection from two doses, Assoc Prof Mak said.
"This does support the view that vaccination does protect you and reduce the risk of you getting infected," he said.
While Assoc Prof Mak said it was still not possible to pin down specific modes of transmission in the cluster, he said it was likely that close contact among tenants, stallholders and staff would have contributed to exposure and spread in both mask-on and mask-off settings.
"It is clear that the circumstances were right, in a setting where the market and food centre had a number of cases, for transmission to take place," he said.
"All staff and tenants at both the market and food centre have been issued with quarantine orders, and this includes also cleaners, suppliers, delivery drivers that we can identify, as well as other regular visitors to the premises there," he added.
Assoc Prof Mak said MOH is conducting further swab testing operations in the Bukit Merah and Tiong Bahru area to assess the degree of spread.
This includes blocks 116 and 117 Bukit Merah View, an NTUC FairPrice outlet at Lengkok Bahru, Redhill Market and Food Centre, Tiong Bahru Plaza, retail outlets in Redhill Lane and Redhill Close as well as other premises in the vicinity.
"These are based on where the cases have been detected and the activity mapping," Assoc Prof Mak explained.
He said MOH is also watching other clusters in the vicinity, including those at Eng Watt Street and Eng Hoon Street in Tiong Bahru.
"We remain vigilant to assess whether or not there are any linkages that can be established between these other clusters, and that at 115 Bukit Merah View," he said.
"Phylogenetic testing is being conducted for all these cases ... but the results of the phylogenetic testing are not out yet, and we will use these test results when available to establish further links which we will then report in due course."
Assoc Prof Mak thanked those affected by the testing operations for their patience, noting that these were "disruptive" for business in the area.
"We believe this is important, because by participating in this and helping us to get control of this infection, it contributes to us keeping Bukit Merah, the Tiong Bahru area and the rest of Singapore safe for all of us," he added.