SINGAPORE - Nine children and four staff from PCF Sparkletots Braddell Heights are linked to the 22-case cluster there, said the Early Childhood Development Agency (ECDA) on Monday (Sept 13).
The rest of the cases are household contacts.
The cluster was first reported by the Ministry of Health (MOH) last Saturday when three new cases were added.
The affected children and staff were last present at the pre-school at Block 335 Serangoon Avenue 3 between Sept 2 and 6.
They had mild or no symptoms.
The children are from the same class, while all four infected staff are fully vaccinated.
All staff and children of the pre-school were placed on leave of absence and close contacts have also been placed under quarantine.
All remaining staff of the pre-school have tested negative as at Sunday.
The pre-school was closed last Tuesday and has since completed thorough cleaning and disinfection of its premises.
Ms Marini Khamis, senior director of PCF's pre-school management division, told The Straits Times on Sunday that the centre will reopen on Sept 21 if there are no further developments.
A spokesman for the ECDA said that pre-schools will continue to be vigilant and adhere to strict safe management measures.
These include ensuring good personal hygiene, limiting interactions of children within their respective classes, and restricting visitors to centres. Health screenings are also conducted up to three times a day.
ECDA said: "The precautionary measures that have been put in place in pre-schools are only effective if the pre-school community works together and exercises social responsibility.
"We encourage parents to seek medical attention promptly if their child is unwell. Educators are likewise encouraged to do so. Parents with household members who are unwell are also encouraged to keep their children at home."