300,000 Cases in Islamabad and Understanding Seroprevalence Survey

Mawra Irshad
Computational Biological, Data Analyst in TTQ- COVID Surveillance Cell, Islamabad.

A piece of fascinating but tragic news on the media was circulated about 300,000 cases in Islamabad lately. Efforts are continuing to restrain the virus; however, given the many uncertainties about pathogen transmission and virulence, the effectiveness of those trials is unexplored.

Based on the stratified systematic random sampling of the 2 Million residents of the Federal capital, a sample of 4,328 people was selected per probability proportionate to size technique giving equal representation to rural and urban residents

The new about Islamabad got 290,000 cases was being researched and coming to the conclusion we found that seroprevalence Surveys needs to be understood before getting panic.

Government of Pakistan conducted a large scale Seroprevalence survey in the geographical region of Islamabad; Seroprevalence surveys use serology tests to identify people in a population or community that have antibodies against infectious disease. Antibodies are specific proteins made in response to infections. Antibodies are identified in the blood of individuals who are tested after contagion; they show an immune response upon the infection. Antibody-test results are especially important for detecting previous infections in people who had few or no symptoms. It is unknown yet if having antibodies to the virus that causes COVID-19 can protect someone from getting the virus again, or, if they do, how long this protection might stay.

Islamabad has a population of 2 Million, almost equally divided into rural and urban areas. The sample size was taken equally from both urban and rural.

The very small size of the sample was selected and out of a population of 2 Million, 4,328 people were picked.  14.5% of total showed prevalence, upon converting 14.5% of 2 Million is 290,000 individuals, who have been infected from the SARS-CoV-2 virus, immune and developed antibodies too. Keeping in mind that a vast majority of these were asymptomatic, including documented and undocumented data.

This kind of large-scale geographic seroprevalence surveys are performed in different parts of the world, in the US, a survey was conducted in California, blood samples were taken from random people for antibody testing and the survey revealed that actual cases were 50-80% more than the detected cases. Initial seroprevalence estimates propose that the number of infections was much greater than reported cases, potentially indicating persons who had mild or no ailment or who did not seek medical attention or got tested, but who still may have contributed to ongoing virus transmission in the population.

Tracking population seroprevalence over time, in a diversity of specific geographic sites will familiarize models of virus transmission and policy declarations regarding the influence of social distancing and other defensive measures. CDC and now Pakistan plans to conduct seroprevalence surveys at regular intervals across the country to detect ongoing incidence, to determine if antibody responses are waning, and to assess herd immunity.

A similar survey was conducted in London too, that showed 17.5% of the population has already caught the virus.

The results are worrisome but if we look from another angle, the death rate of COVID is lesser than the predictions.

The detected cases in Islamabad are 14, 500 and 127 deaths, 1%. Death rate becomes 0.05% if we take it out from 300,000 is said by a government survey. CDC reports in the US, the flu death rate was 0.1%, less than the flu.

We cannot say that the death rate is very low and we should take it seriously but these type of surveys in the US and UK shows a very interesting picture too.

We cannot count an exact number of affected people. With the passage of time, we will get the data and can count the figures and stats better. If the survey is correct about 300,000 people get affected by COVID-19 that means we are actually moving towards the concept of herd immunity.

Another face of the picture is that there are cases reported where one a person has been affected by COVID for 2 times, we are not even sure about the antibody working duration either they remain there for a few months or it is a lifetime immunity.

Coming times and the facts and figures can tell us better about COVID-19.

Last but not the least, Results from seroprevalence surveys should not be paraphrased to mean that individuals who have diagnosed positive for having SARS-CoV-2 antibodies are protected and immune. We cannot distinguish whether having SARS-CoV-2 antibodies produces protection against becoming infected again.

Because people do not always know if they are infected with SARS-CoV-2, the populace should continue to take steps to help prevent the spread of COVID-19, such as wearing face coverings when outside the home, remaining six feet apart from other people, washing hands frequently, and staying home when unwell, stay clean and choose a healthy diet, including more fruits in it. Moreover, people should spend Eid-ul-Azha responsibly.