New measures were announced on Friday (May 14) by the multi-ministry task force on Covid-19 in light of increased community cases. This will take effect from this Sunday for a month to June 13.

1. Reduced group size from five to two people

2. No dine-in allowed, among tighter measures for higher-risk settings

3. Work from home as default for workplaces

4. Reduced event sizes and mall capacity. Currently, events can have 100 attendees without pre-event testing and 250 with pre-event testing. This will be scaled down to 50 and 100 attendees respectively

5. The cap of five distinct visitors per household per day will also be reduced to two distinct visitors per household per day

6. Other activities that will not be allowed during this period include strenuous indoor exercise classes or strenuous individual and group indoor sports and exercise activities,

7. Museums and public libraries will also be allowed to operate at a reduced capacity of 25 per cent.

As of the latest news, one student each from The Learning Lab tuition centre in United Square and the HCL Education Centre in Katong V have tested positive for Covid-19. According to MOH’s daily case update on Friday, the tuition centre at Katong V was among places visited by community cases. In addition, just three days ago, five primary school students have tested positive for the virus after attending a lesson run by an infected tuition teacher at Learning Point in Parkway Centre. 

There appears to be a few Covid-19 clusters mushrooming, starting from the food canteen, hospitals and now enrichment centres. We would expect more teachers and students to test positive in the days ahead. An obvious question: How did this happen? Didn’t hospitals and enrichment centres have Safety Management Measures in place to protect the healthcare workers, teachers and students? 

Students sit elbow to elbow in some tuition centres, and lifts are packed with students and parents before and after the lesson. Some students have bubble tea drinks in their hands while they laugh and chatter happily with their friends. Families visiting in the hospital wards are unmasked while eating the snacks they bring along during visiting. Friends enjoying hours of good chat, unmasked, over a cuppa in cafes or coffee shops. 

At best, this is inconscient on our part as a community. At worst, it’s negligence that endangers others. 

The most significant Covid-19 risk is being around laughing, singing, coughing, sneezing and unmasked while eating or drinking. So the best Covid-19 prevention is to keep humans far apart from one another and interact remotely as far as possible. There are three effective ways to stop the risk of viral spread. 

The main one is to keep your mask on at all times and do not touch your face with your hands. Of course, you will need to wash your hands before doing so. Though masking can slow down the viral-laden aerosols coming out from our orifices on our face, it doesn’t replace distancing. Even with your mask on, you need to keep your distance at least 1 metre from one another to reduce the spread of the virus. And if you are in a poorly ventilated indoor space, masking and safe distancing can reduce but not stop the spread of the virus. Superspreading events where the virus infects many people in one setting tend to occur in poorly ventilated indoor spaces. Studies recommend changing the air in the room four to six times per hour through any combination of the following: ventilation with outdoor air, recirculated air that passes through a filter with MERV 13 rating or portable air cleaners with HEPA filters.

Precautions like temperature check and vigilant Covid-testing can be part of the mitigation strategy, but they each come with pitfalls. For example, a temperature check may help identify a person with fever and is therefore infectious. But a person can be contagious without any symptoms, and not everyone who is infected gets a fever. 

Recurrent testing enables infected individuals to be identified and isolated to reduce spread. But a negative Covid-19 test doesn’t necessarily mean a person is virus-free. Experts reported false-negative rates between 2% and 29% (equating to the sensitivity of 71-98%), based on negative RT-PCR tests, which were positive on repeat testing. Also, the accuracy of viral RNA swabs varies depending on the size and quality of sampling, the state of the disease and the degree of viral multiplication. Disease prevalence can also affect estimates of accuracy. Tests developed and evaluated in a population with high prevalence may yield a lower sensitivity when applied in a lower prevalence setting. 

There is no replacement for the primary prevention measures: proper masking, distancing and adequate ventilation. 

Allen JG, Ibrahim AM. Indoor Air Changes and Potential Implications for SARS-CoV-2 Transmission. JAMA. Published online April 16, 2021. doi:10.1001/jama.2021.5053
Arevalo-Rodriguez I, Buitrago-Garcia D, Simancas-Racines D, et al. False-negative results of initial RT-PCR assays for covid-19: a systematic review.