In Islamabad, over 14% of population may have developed antibodies against Covid-19
Islamabad (TP) July 16, 2020: A new survey of the National Institute of Health (NIH) has said that 14.5 per cent or 290,000 individuals in the Islamabad Capital Territory (ICT) may have been exposed to novel coronavirus, now designated as the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).
The NIH’s “Sero-Epidemiological Survey for COVID-19 in ICT” says that the results of the survey showed that the calculated prevalence of COVID-19 in ICT is 14.5 per cent which translates to 290,000 individuals, who have been exposed to the SARS-CoV-2 virus and have developed the immunoglobulin against the virus.
A senior NHA official, however, clarified that the survey should not be misinterpreted or misconstrued that the number of active Covid-19 cases is 290,000 in the ICT jurisdiction.
“In the backdrop of the current COVID-19 situation in the country, an enhanced surveillance strategy that focuses on population-based methods is mandatory to understand the actual situation and then successfully control the pandemic. Asymptomatic/mild cases of COVID-19 are usually not picked up on routine surveillance and hinder estimation of true population infection rate. Therefore, the estimation of the true population infection rate is mandatory to effectively guide public health interventions. To address the above needs, following WHO guidelines, a population-based, age-stratified, sero-epidemiological survey was conducted in Islamabad to determine the extent of infection in the general population, age-specific attack rates and the fraction of asymptomatic or subclinical infections,” said a press release issued here.
“The cross-sectional survey was conducted between June 1 and June 25, 2020. The geographic scope of the survey was limited to the Islamabad Capital Territory (ICT). Equal representation from the rural and urban areas was ensured. According to Pakistan Bureau of Statistics, ICT is divided into 44 administrative units: 12 urban and 32 rural; and as per the National Census 2017-18, the population is 2,006,572 (urban 1,014,825; 50.6% and rural 991,747; 49.4%),” it added.
“Applying the stratified systematic random sampling using probability proportionate to size technique a sample of 4,328 was calculated. A structured, pretested questionnaire was used to gather demographic, clinical, exposure and risk factor data from the community. Blood samples were collected from each participant and tested for immunoglobulin against SARS-CoV-2 on Chemi-luminescence. Throat/ nasopharyngeal swabs were also collected from those having symptoms or contact history with a positive case for PCR testing. All samples were tested at Virology lab, PHLD at National Institute of Health,” the press release said.
According to the survey “the preliminary analysis showed a prevalence of COVID-19 to be 14.5 per 100 population. As for the area wise distribution of the disease, rural union councils were more affected. Out of all the union councils, Chattar was found to be most affected followed by union councils Muhrian and Tarlai Khurd. Considering age, the most affected group was 41-50 years followed by 31-40 years and 51-60 years age groups. RT-PCR positivity rate was found to be 17%,”.
The press release further added that “This should be seen in the context that a vast majority of the individual already exposed to the virus are asymptomatic and therefore escape detection. This was one of the objectives of this survey to uncover the hidden/already exposed individuals in the communities and these must not be taken as new cases/patients.”
NIH doctor Mumtaz Ali Khan while talking to The Punch said that some media outlets have misinterpreted the survey by stating that 14 per cent of the population or over 0.29 million people in Islamabad were affected by the coronavirus. He said that the survey should not be misconstrued or misinterpreted, as, according to him, serological surveys are a valuable tool to assess the extent of the epidemic, given the existence of asymptomatic cases and little access to diagnostic tests. This population-based survey aims to estimate the seroprevalence of SARS-CoV-2 infection at the national and regional level.
He said that a sizeable number of people with symptoms compatible with COVID-19 did not have a PCR test and over 14 per cent of infections determined by serology were asymptomatic. “These results emphasise the need for maintaining public health measures to avoid a new epidemic wave,” he said.
Dr Mumtaz said that they will issue a press release tomorrow or hold a press conference to do away with the misinterpretation of the survey report.