COVID-19 in India: 1 in every 15 individuals exposed to novel Coronavirus by August, finds second round of sero-survey

Coronavirus sero-survey in India: Only 6.6% of Indian population exposed to COVID-19 so far! The Indian Council of Medical Research (ICMR) released the findings of the second nation-wide sero-survey on Tuesday. The survey found that by August, 6.6% of population surveyed, or one in every 15 individuals, of the age of 10 years or more have been exposed to SARS-CoV-2, the novel Coronavirus causing COVID-19. This translated to the fact that a large portion of the country’s population is still vulnerable to the novel coronavirus, a report in The Indian Express said.

ICMR Director General Balram Bhargava was quoted by the report as saying that 29,082 individuals were surveyed in the second sero-survey, conducted between August 17 and September 22. While the overall exposure to Coronavirus was found in 6.6%, the prevalence was found to be higher in people aged 18 years and above, standing at 7.1%.

The report stated that the first sero survey, which was conducted on adult individuals across 70 districts between May 11 and June 4, had found a prevalence of a mere 0.73%. As compared to this, the prevalence rate has significantly increased in the second sero survey, which was also conducted across the same 70 districts, only this time, counting children above 10 years of age as well along with the adults.

Another significant finding of this survey was that children were also vulnerable to the infection. Bhargava was quoted as saying that the prevalence did not differ according to gender or age, adding that all age groups above the age of 10 had been exposed to the infection. This changed the perception of the health authorities, which were earlier of the view that the virus was not affecting people below the age of 18 years, Bhargava further said.

Bhargava said that the data showed a large group of people was still vulnerable to the infection, and said that prevention fatigue needed to be avoided. He asserted that it was important to stick to the 5T strategy—test, track, trace, treat and use technology. Apart from this, physical distancing and face masks were still essential, he said, and stated that the states must most effectively implement containment strategies, especially keeping in mind the pending festivities, winters and mass gatherings.

The survey had been conducted to test the prevalence of infection amid the gradual reopening of the country, easing of the restrictions and resumption of economic activities in the country. Another key finding from the survey was that the risk remained highest in urban slums, where the prevalence stood at around 15.6%. This figure contrasted with 4.4% prevalence in rural areas and 8.6% in non-slum urban areas, the report added.

On this, Bhargava said that risk-focused and people-centric interventions were more and more necessary in urban slums, especially with a focus on protection of elderly and individuals suffering from comorbidities.

The report added that the effect of increased testing within the past two months was also visible, as the new sero-survey found 26-32 infections for a reported case by August, as against the figure of 81-131 infections per reported case back in the May sero-survey.

The report also quoted NITI Aayog member Dr VK Paul as saying that the dimension of the novel Coronavirus is much wider. While the dimension of asymptomatic infected individuals is a well-known one, a notable finding was that in May, there were 81-131 cases with one confirmed case, while the number now stood at 26-32. This, Dr Paul said, indicated that the health authorities were now tracking the virus more intensely. However, a key point to remember was that not every asymptomatic individual could be identified—which is what made sero-survey an important additional tool for contact tracing.

Dr Paul further said that the data from this sero survey had to be seen from two perspectives in order to implement future containment measures. He said that the findings from the second round of sero survey, which was held in a systematic way, can be looked at in two ways – one being the efficacy of the containment measures that had been adopted, which kept prevalence rate low despite the unlocking of the country, and the second being that over 90% of people are still vulnerable to the infection, which means the risk is still high.

He added that the spread of respiratory viruses was faster in the winter months, meaning that social distancing and masks would be more crucial in the next few months. Thus, there would be a need to celebrate the upcoming festivals in small, intimate groups only.

Bhargava said that at present, India’s seroprevalence was comparable to that across the globe. Currently, the US has a seroprevalence of 9.3%, Switzerland has 8%, the UK has 7% and Belgium has 5%.