Explainer: A closer look at the ‘inevitable’ rise in Covid-19 cases in schools as community infections surge

• At least 14 schools have had students testing positive for Covid-19 over the past week
• They included a primary school where two students from the same class were infected
• MOE said there was no school-based transmission in the recent string of infections among children
• Medical experts said it is hard to eliminate the possibility of such transmissions, but contact with cases outside can rule out an infection within the school

SINGAPORE — Two classmates at Xingnan Primary School in Jurong have come down with Covid-19, prompting the school to conduct home-based learning for its students for up to two weeks.

This comes amid a string of circulars from more than a dozen primary and secondary schools over the past week, including at least four sent out on Tuesday (July 27) alone, informing parents of positive Covid-19 cases among their students.

In another circular on Monday, Pei Chun Public School told parents that a third student had tested positive for Covid-19. This student had been swabbed as part of a testing operation for those who had been in close contact with one of two other pupils who had earlier contracted the disease.

Nonetheless, TODAY understands that the authorities are ruling out school-based transmission in these cases.

Here is a closer look at the available information so far and what health experts say could have led to the two cases at Xingnan Primary.

THE TWO CASES AT XINGNAN PRIMARY SCHOOL

In a letter to parents seen by TODAY that was sent out last Friday, Xingnan Primary School principal Charles Chan said two Primary 5 pupils had tested positive for Covid-19.

One of them was last in school on July 21 and was well. The second was last in school on July 23 and had gone home early that day as he was feeling unwell.

Upper primary students at the school were put on home-based learning for two weeks and lower primary students for one week, starting from Monday. Preliminary oral examinations for Pri 6 students were postponed.

Students and staff members who were in close contact with the students have been identified and placed on leave of absence, said Mr Chan. The school will also thoroughly clean and disinfect its premises.

THE THREE CASES AT PEI CHUN PUBLIC SCHOOL

Pei Chun Public School principal Lim Meng Wei informed parents in a letter on Saturday that two pupils had been infected — one in Pri 3 and another in Pri 6.

Mr Lim said the two cases were unrelated and that the two had not been in school while they were infectious. They were both last in school on July 16.

Mr Lim added that there was no evidence of school-based transmission in the two cases, but MOH was arranging mandatory swab tests for students and teachers who were close contacts of the Pri 3 pupil as a precaution.

In an update two days later, Mr Lim informed parents in another circular that a third student — a close contact of the Pri 3 pupil —had tested positive after being swabbed in the testing operation.

As such, the school will be placing all Pri 3 students on home-based learning from July 27 to Aug 6. Students in other levels will continue to attend classes in school as usual.

‘NO SCHOOL-BASED TRANSMISSION’

MOE told TODAY last Friday that there had not been any school-based transmissions in the recent wave of cases involving students.

In response to a follow-up query, the ministry reiterated on Tuesday that its initial statement remained valid.

In a separate statement that same day when asked about the two cases at Xingnan Primary School, MOE said that the rise in the number of students and staff members testing positive for Covid-19 in the past few weeks is in tandem with the rise in cases within the wider community.

“The students have mild symptoms, and thus far, all the students are recovering well,” it said.

If there are confirmed cases in a school, the school will take necessary measures to safeguard students and staff members, and curb the risk of any transmission, MOE added.

RISING CASES ‘INEVITABLE’: EXPERTS

Neither MOE nor Mr Chan’s letter to parents provided information on how the two classmates at Xingnan Primary School were infected.

If the two cases also happened to be close contacts of separate Covid-19 cases outside school, such as within their own households, then it would be more likely that they were infected at home, said Dr Alex Cook, an associate professor at the National University of Singapore’s (NUS) Saw Swee Hock School of Public Health.

Amid the rising community cases, students have been returning to schools even as employees continue working from home by default. So why has Singapore not seen any instances of school-based transmissions recently?

Dr Leong Hoe Nam, from Rophi Clinic at Mount Elizabeth Novena Specialist Centre, said that’s probably because the major clusters involving the Jurong Fishery Port and markets are not places that school children tend to go.

And if parents get infected from these places, their children would get quarantined quickly, making subsequent spread less likely.

Still, at least one medical expert said it is possible that the two classmates could have been infected via transmission within the school, unless there is evidence to prove otherwise.

Dr Paul Tambyah, president of the Asia Pacific Society of Clinical Microbiology and Infection, said that further phylogenetic studies — or molecular analyses — will have to be completed to categorically rule out any school-based transmission.

“Those are probably pending,” he said.

HOW WORRIED SHOULD PARENTS BE?

Almost all the infectious diseases experts pointed out that infections among children are mostly mild and they are far less likely to develop severe complications from Covid-19 than adults.

While some parents may be understandably concerned, it is natural that school children would be infected as the number of cases within the community rises, said Associate Professor Hsu Li Yang from NUS’ Saw Swee Hock School of Public Health.

“In the future, as the majority of adults become vaccinated and physical distancing and travel restrictions are eased, it is also inevitable that we will see more infections among children,” said the former clinical director of the National Centre for Infectious Diseases.

SCHOOLS AFFECTED

Over the past week, at least 14 schools including Pei Chun Public School and Xingnan Primary School have had students or staff testing positive for Covid-19, according to circulars to parents seen by TODAY.

The most recent cases included Jurong Secondary School, West Grove Primary School, Stamford Primary School and Qifa Primary School. Parents of students from these schools were notified on Tuesday.

The letters from the 14 schools that TODAY has seen have been verified by MOE.

Aside from Pei Chun and Xingnan, they are:

• Stamford Primary School: All Pri 5 students placed on home-based learning from July 28 to 30 after a Pri 5 student tested positive

• West Grove Primary School: Students from all levels had lessons from home on July 28 after a Pri 3 student tested positive

• Jurong Secondary School: A student who was not in school while he or she was infectious tested positive on July 26

• Qifa Primary School: A Pri 2 student who was last in school on July 23 tested positive

• De La Salle School: Students from all levels had lessons from home on July 27 after a student tested positive

• Henry Park Primary School: All Pri 1 students to have lessons from home from July 26 to 30 after a student tested positive

• Ang Mo Kio Secondary School: All Secondary 1 students had home-based learning from July 26 to 28 after a Sec 1 student tested positive

• St Margaret’s Secondary School: All Sec 2 students had home-based learning from July 26 to 28 after a Sec 2 student tested positive

• Anglo-Chinese School (Barker Road): Students from all levels had lessons from home on July 26 after a Sec 4 student tested positive

• Anderson Secondary School: All Sec 2 students placed on home-based learning from July 26 to 28 after a Sec 2 student tested positive

• Raffles Girls’ Primary School: Students from all levels had lessons from home on July 26 after a Pri 1 student tested positive

• CHIJ (Katong) Primary School: A student tested positive on July 23 while in quarantine. She was last in school on July 19

MOE said it always acts quickly in the event of a positive case to stem the spread of the virus.

“(This) includes issuing leave of absences quickly to close contacts of confirmed cases, and implementing home-based learning for affected levels or the entire school out of an abundance of caution,” it said. Close contacts are also put under quarantine by the MOH.

Students and staff who have been put under MOH’s health risk warning will also be put on approved absence and will only be allowed to return to school after they get a negative result on a polymerase chain reaction (PCR) swab test.

Those put under such health-risk warnings include individuals identified to be a casual contact of a Covid-19 case, or have visited specific higher-risk hot spots on the same day as an infected person, MOH’s website stated. They must self-isolate until they receive a negative PCR test.

If the household member of any students of staff member is put on such a warning, they will also be placed on approved absence and can only return to school after their household member tests negative for Covid-19.