At the end of May this year, around 62,000 COVID-19 cases had been recorded in Singapore.
Of this amount, 550 had been infected with the Delta variant of the coronavirus, which was first detected in India.
428 of these cases are local while the remaining 122 are imported.
According to ST, which accessed global database GISAID on Wednesday (8 June), 20 people in Singapore had been infected with the Delta variant in the past four weeks.
These 20 cases make up around 87% of COVID-19 cases from Singapore reported on GISAID over the same length of time.
If you’re unfamiliar with GISAID, it’s an online platform that allows research groups to upload genetic sequences of the virus that causes COVID-19.
However, according to Associate Professor Raymond Lin, director of the National Public Health Laboratory at the National Centre for Infectious Diseases (NCID), submission of data to GISAID is purely on a voluntary basis, so laboratories have full control over what information they choose to upload to the platform.
Hence, Prof Lin said that if there is no submission from a country, the entry will be labelled as “the lowest in the world”, making the numbers submitted on GISAID less “meaningful”.
Examples of this include Canada, Argentina and Sri Lanka, which were seen to have zero delta variant cases on the platform.
Naturally, Prof Lin explained that GISAID data is more an indication of a country’s overall ability to conduct sequencing.
He revealed that Singapore conducts sequencing for all confirmed cases of COVID-19, but not all cases result in successful sequencing “due to inadequacy of specimen material”.
However, all cases with high-quality sequences are submitted to GISAID.
Dr Sebastian Maurer-Stroh, executive director of the Agency for Science, Technology and Research’s (A*Star) Bioinformatics Institute, echoed Prof Lin’s assertions, adding that, “Higher number of genomes is not a sign of having more of a specific variant than other countries unless both compared countries have the same surveillance intensity. For example, it is not true that Britain has more Delta variant cases than India.”
According to GISAID data, there were 16,779 Delta variant Covid-19 cases in Britain over the past four weeks while India had 330, which goes to show how “meaningless” the data can be since it’s purely voluntary.
Dr Maurer Stroh then advised studying the frequency of variants in countries with high genomic surveillance efforts in order to get a more accurate idea of how widespread a particular variant is.
As of 31 May, here are the statistics of local cases of COVID-19 infection involving a variant of concern:
- Delta variant: 428 people
- Alpha variant (first detected in Britain): 7 people
- Beta variant (first detected in South Africa): 9 people
- Gamma variant (first detected in Brazil): 5 people
To know more about why viruses mutate into variants of concerns, watch this video to the end:
Featured Image: aslysun / Shutterstock.com