She added that calls were also made about the Tuesday cases.
'Unfortunately, we missed out two. These are the only two I know of. We thought we had already informed them.
'Nobody wants this to happen. We are really doing whatever we can, informing parents through circulars, e-mails, phone calls and SMSes.'
A circular dated 28 Oct listed more than 10 preventive measures that the centre staff were taking, such as health screenings four times a day where temperature is taken and children are checked for ulcers, blisters, red spots of bumps.
Toys, mattresses and furniture are disinfected at least once a day.
The circular also said the Ministry of Health (MOH) had been notified and asked parents to look out for symptoms of HFMD, such as fever lasting a few days and small fluid-filled blisters on the hands, feet and diaper areas.
MOH stipulates that it must be notified if two or more cases of HFMD are diagnosed in a centre.
Children who are unwell should be taken to a doctor and allowed to rest at home until certified medically fit to attend school.
Ms Ong said this is where some parents are not co-operative.
She said: 'I called parents of infected kids and asked them to keep their siblings at home, but some insisted on taking them to the centre.
'They came with doctor's certificate to say the child is not infected. But later on, it turns out that she is. What can I do?'
4 THINGS ABOUT HAND, FOOT AND MOUTH DISEASE
About 12,000 children have caught HFMD this year, with close to 30 per cent of infections caused by the virulent enterovirus 71, orEV71.
HFMD is usually a mild childhood illness which causes rash and blister spots on the hands, feet and buttocks, and sores in the mouth and throat.
It is passed through bodily fluids like saliva. It can be caused by about 80 viruses but EV71 is particularly feared as it is behind most of the seven deaths during the 2000- 2001 outbreak here.
The rise in the EV71 cases made MOH tighten its rules. If the virus is active for more than 15 days and more than 13 children at the centre are affected, it will be temporarily shut down.
This story was first published in The New Paper on Oct 31, 2008.