SINGAPORE - Four students and one non-teaching staff from five different schools have tested positive for the coronavirus.

In a statement on Sunday (June 7), the Ministry of Education (MOE) said all five cases had mild symptoms, and are from Anglican High School, CHIJ Katong Convent, CHIJ St Theresa's Convent, Geylang Methodist Secondary School and Hwa Chong Institution.

They are thus not a cluster, the ministry said. The cases were picked up as part of surveillance testing that began since June 2 for all students above the age of 12 and school staff who are diagnosed with acute respiratory infection when they first see a doctor.

"While positive, the tests for all five cases revealed low viral loads," MOE said, adding that a repeat test using new samples showed that all five cases were negative.

The evidence thus suggests the cases were likely infected during the circuit breaker period, and not after schools reopened on June 2, the ministry added.

In all, 29 staff and 100 students who were in contact with the confirmed cases in school have each been issued with a 14-day leave of absence by MOE or home quarantine order.

The students and staff who are on quarantine will be swabbed for Covid-19 once before the start of the quarantine and once at the end.

The schools have also been thoroughly cleaned and disinfected, following the confirmation of the five cases.

At a virtual media session on Sunday, Education Minister Ong Ye Kung said: "I think the safe measures have been very consistently applied across all schools, but it just so happens that these five schools happened to encounter cases. In one of them, the student did not come to school at all (as) it wasn't his turn for classroom learning and he was doing the weekly rotation.

"I think this is a good reminder for all schools not to be complacent...and continue to be on the alert, and make sure that safe measures are properly implemented."

Schools had reopened on June 2 after two months of school closure.

Students were put on full home-based learning for about a month from April 8 as part of circuit breaker measures to stem the spread of the coronavirus. They then had a one-month school holiday after the June holidays were brought forward to May 5.

The student from Hwa Chong Institution was last in school on April 7, before the start of full home-based learning.

One of the five began having symptoms as early as May 31, while another had onset of symptoms on June 2 and the other three on June 3.

MOE said all five were screened when entering their schools, and did not have a fever or visible flu-like symptoms.

Mr Ong said: "As we step out of the circuit breaker period and engage in normal activities, all of us must play our part, particularly in the school environment. If you're sick or if any of your family members are sick, don't come to school.

"We have always said we will step up testing and we will have more rigorous contact tracing in order for us to step out of the circuit breaker and live life as normally as we can... But as we do so, we will discover more cases. It is important that we detect these cases early, identify the close contacts, trace and quarantine them."

Mr Ong added that "it is very natural that when we see these extra cases, we feel less safe, although the reality is that we are safer (as we test more)".

On surveillance testing, MOE said that for younger students, swabbing may be uncomfortable for them and requires healthcare professionals with special expertise. However, students who are 12 years old and below will still be tested if they persistently display respiratory symptoms.

Arrangements for all schools, including the five affected schools, remain unchanged.

This means that for this coming week from Monday (June 8), Primary 1, 2, 3 and 6 pupils, as well as Secondary 3, 4 and 5 students will attend classes in school, while the remaining levels will be on home-based learning, based on the earlier announced weekly rotation schedule.

Graduating cohorts of Primary 6 and Secondary 4 and 5 attend classes in schools from Mondays to Fridays.

The rest rotate weekly between learning in school and learning at home. Last week, those in Primary 4 and 5 as well as those in Secondary 1 and 2 returned to school. They will be doing home-based learning this week.

Mr Ong said the ministry would consider closing a school if a cluster formed in that environment.

"That has not happened yet and we do our best to prevent it from happening. One of the ways to prevent it is to step up our testing regime so that we can detect (cases) early, so that we don't have the chance of developing a cluster and having transmission within the school," he said.

The ministry noted that some of the students on leave of absence have registered for the Mother Tongue Language (MTL) examinations on June 18.

At the virtual media session on Sunday, Director of Schools Liew Wei Li said the affected students should end their LOA or quarantine on June 16 or 17 to be back in time for the exams. They can also opt to take the exams at the end of the year.

"We do know that parents and students are anxious but the schools will provide additional support like extra lessons (online) and extra practice at home for their papers so they will be given more than sufficient support to ensure they are prepared for the exam," said Ms Liew.

The Singapore Examinations and Assessment Board will also apply special consideration during grading for these students, MOE said.

Ministry of Health's Director of Medical Services Kenneth Mak said it is vital for the community to remain watchful despite low community transmission numbers.

"It is important for all of us not to be complacent, or to believe that just because in previous weeks we had lower incidents of community cases, that all is well and there is no possibility of spread," he said at the virtual media session on Sunday.

"Spread can still occur if we lose our vigilance and it is important for all of us still to be disciplined in maintaining our safe distancing measures - wear a mask, avoid unnecessary movements away from home, at work or at schools, and to avoid situations where we gather in crowds."

In its statement, MOE said the schools have implemented a set of comprehensive safe management measures to bring students back in a careful and safe manner.

The ministry also gave the assurance that while it expects to see such confirmed cases from time to time, those at risk of being infected will be quickly isolated to prevent the virus from spreading and allow schools to continue.