S African variant dominant in Dhaka

The South African variant of Covid-19 is dominant in Dhaka, revealed an icddr,b study last night.

"A dramatic change in the distribution of variants was observed when the South African variant appeared. It became the most prevalent variant during the third week of March 2021 after replacing all other variants," said the study published at the icddr,b.

"Between March 18 and 24, we have analysed the genomic sequence of around 57 samples of Covid-19 positive patients. Of those, 46 or more than 80 percent were found to have been infected with the same South African variant," Dr Mustafizur Rahman, senior scientist at the icddr,b, told The Daily Star last night. 

He said that they found the SA variant in 64 samples out of 99 positive samples tested last week (between March 12 and 17).

"In the first week of March [between March 5 and 11], we genomic-sequenced around 30 samples but found no existence of the South African variant," said the lead scientist.

He said that samples were collected from 13 districts but most were collected from Dhaka, adding that the study represents mostly the situation in Dhaka.

"We observed that the South African variant became the most prevalent variant during the third week of March by replacing other variants, including the UK variant. Our findings warrant continuous monitoring of genetic variations of SARS‐CoV‐2, which is crucial for vaccine effectiveness and patient's management," said Rahman.

Recently, the UK, South African, and Brazilian variants have spread all over the world, according to different studies across the globe.

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

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

Between 01 January and 24 March 2021, a total of 16,265 specimens were tested for Covid-19 using RT-PCR in icddr,b's Virology Laboratory.

Of those, 2,751 (17 percent) were positive, said the study.

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 UK variant gradually increased over time until the second week of March 2021, with the highest positivity rate [52 percent]", it said.

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

It also stressed that all need to abide by the restrictions recently announced by the government.

The SA variant, known as the 501.V2 variant, was identified by South African researchers and details have been sent to the World Health Organization in December last year.