At least 45 per cent of the population in Dhaka city have developed antibody against COVID-19, found the first-ever study on COVID-19 seroprevalence in Bangladesh.
The study, carried out recently by the Institute of Epidemiology, Disease Control and Research and ICDDR,B, also found that the rate of COVID-19 antibody prevalence among slum people was a whopping 74 percent.
The study findings were disseminated at a city hotel on Monday.
The study tested 553 symptomatic and 817 asymptotic patients with IgG and IgM from 3,227 households in the capital.
Besides, 96 symptomatic and 314 asymptotic slum people were tested with IgG and IgM from 960 households.
Presenting the findings, study lead researcher Firdausi Qadri said that it was an ‘encouraging’ rate of antibody among people in Dhaka.
‘It suggests onset of herd immunity,’ said Firdausi, a senior scientist at ICDDR,B.
Epidemiologist Mustuq Husain told New Age that the prevalence of antibody in over 60 per cent population is considered herd immunity.
‘The findings suggest that the slum people have higher rate of antibody against COVID-19,’ he said.
Firdausi said that the seroprevalence findings should not be mixed up with the prevalence rate of COVID-19.
‘The prevalence rate might be higher,’ she said.
Replying to a question, she said that the seroprevalence rate could not be used for predictions about a second wave of infection.
‘Antibodies are short-lasting and we’re hearing about second-time infections in some people,’ Firdausi said.
Another study presented at the event found that 9.8 per cent of the Dhaka city population had COVID-19.
But the rate was 5.7 per cent among the city’s slum people.
Replying to a question about higher antibody among slum people but a lower prevalence in the same population, Firdausi said that slum people were mostly asymptotic but it could not be said that this population was less infected.
Another study on genomic epidemiology of COVID-19 in Bangladesh found that 19 distinct SARS-COV-2 lineages or descendants were spreading in Bangladesh.
The three main localized lineages found in Bangladesh were B.1.1, B.1.1.25 and B.1.36.
Lineages B.1.1 and B.1.1.25 spread to all the eight divisions of the country but B.1.36 was confined mostly to Chattogram division, the study found.
Lead researcher Tahmina Shirin, also director of the IEDCR, said that the study found that COVID-19 was imported to Bangladesh in mid-February and the virus spread all over the country by March.
The genomic data supports the multiple international importation of SARS-COV-2 from the countries of India, Saudi Arabia, the USA and the UK, she said.
Commenting on the studies, IEDCR principal scientific officer ASM Alamgir said that the sample sizes in the three studies were low and should not be accepted as nationally representative.
But, he said, vaccination alongside high antibody prevalence could help contain the coronavirus in the country.
Presiding over the dissemination, Directorate General of Health Services additional director general Meerjady Sabrina Flora said that the studies would be carried out all over the country.
None, she said, is safe from the novel coronavirus and wearing masks, washing hands and maintaining social distancing are crucial because necessary medicines and vaccine are yet to be developed.
‘We’re talking about a second wave of infection, but we’ve to follow the health practices to prevent the spread of COVID-19,’ she emphasised.
National Technical Advisory Committee on COVID-19 president Mohammed Shahidullah said that the findings could be used for future planning.
Health minister Zahid Maleque said that Bangladesh did well in preparation against COVID-19, which helped keep the severity of the novel coronavirus infection low.
Over 5,500 people have so far died of the coronavirus infection while 3.99 lakh have been infected since its detection in the country on March 8.
Want stories like this in your inbox?
Sign up to exclusive daily email
More Stories from Country