South African variant of Covid-19 dominant in Dhaka: icddr,b study

A recent study by the icddr,b revealed that the South African variant of the novel coronavirus is dominant in Dhaka.

Between March 18 and 24, the scientists at icddr,b analysed genomic sequence of around 57 samples of Covid-19 positive patients. Of those, 46 or more than 80 percent were found as same as the South African variant of novel coronavirus.

In the previous week (between March 12 and 17), the icddr,b team analysed genomic sequence of 99 novel coronavirus samples and found South African variant in 64 or more than 64 percent samples.

In the first week of March (between March 5 and 11), the team analysed genomic sequence of around 30 samples. In that case, there was no existence of South African variant. The samples were collected from 13 districts.

Scientists said, a dramatic change in the distribution of variants was observed when the South African variant appeared.

"We observed that the South African variant became the most prevalent variant during the third week of March by replacing the UK variant and others. Our findings warrant continuous monitoring of genetic variations of SARS‐CoV‐2 [novel coronavirus], which is crucial for vaccine effectiveness and patients management," Dr Mustafizur Rahman, senior scientist at the icddr,b who leads the genome sequence team told The Daily Star tonight.

"We have continued genomic sequencing of the samples collected after March 24. The analysis is not ready yet," he added.

Recently, the novel variants of SARS-CoV-2, especially the UK variant named as B.1.1.7, South African variant named B.1.351, and Brazilian variant named P1/P2 have spread all over the world, according to different studies across the globe.

These variants are said to have increased transmissibility and harbour new genetic changes, which may impact clinical manifestation and vaccine effectiveness, scientists said.

icddr,b initiated SARS-CoV-2 variant surveillance in December 2020 in collaboration with the Institute of Epidemiology, Disease Control and Research (IEDCR), Directorate General of Health Services (DGHS).

Between January 1 and March 24, 2021, a total of 16,265 specimens were tested for SARS-CoV-2 using real-time PCR in Virology Laboratory at icddr,b, of which 2,751 (17%) were positive.

The icddr,b scientists identified the first UK variant on 6 January 2021; however, the SARS-CoV-2 sequence database at GISAID.ORG indicated that the UK variant was already circulating in December 2020 in the country.

The icddr,b study shows, the UK variant gradually increased over time until the second week of March 2021, with the highest positivity rate (52%).

Considering the recent upsurge of Covid-19, the icddr,b scientists suggested everyone follow the standard mitigation measures including wearing masks properly, washing hands, maintaining physical distance, and avoiding gatherings regardless of previous infections, vaccination, or new variants.

They also stressed that everyone needs to abide by the restrictions recently announced by the government.