Positivity rate in Ggm dips, increased tests to continue TREND Officials say dip coincides with an increase in RT-PCR test and the district opening its own laboratory for tests

GURUGRAM: For the first time in over two weeks, the district’s daily test positivity rate (TPR) dipped to 3.5% on Monday, with just 43 of the 1,217 new samples testing positive for Covid-19.

For at least three days now, the TPR — defined as the ratio of positive cases to the total number of tests conducted — has inched below the 5%-mark, which is the World Health Organisation’s (WHO) recommended benchmark for lifting restrictions on public mobility (if TPR is sustained for over two weeks).

On July 15, Gurugram’s daily TPR hit a record low of 3.2 %.

However, at the time, the improvement was not consistent.

“We were still seeing an average positivity rate of about 6 to 8%, but now the number is reducing daily. Even in hot spot areas such as Sohna, where the TPR was 11% in mid-July, the positivity rate has now been brought down to about 6% now,” said Dr Jai Prakash Sharma, the Integrated Disease Surveillance Programme’s district surveillance officer in the Gururgam.

Health department data showed a steep dip in test positivity rate beginning mid-June, which coincides with an increase in RT-PCR tests and the district opening its own laboratory for testing of samples.

Until then, nasal swabs taken from patients were being sent to

one of the six other government labs in the state, with most samples being tested at PGIMS Rohtak.

From an average positivity rate of 60% in the first week of June — when as many as 200 new cases were emerging each day — the number dipped to 26% around June 25, after an upgrade in Gurugram’s testing capabilities.

Then, with the introduction of rapid, point-of-care antigen tests in late June, which allowed authorities to more than double the number of daily tests, Gurugram’s TPR (taken as a seven day moving average) saw a sharper dip over subsequent weeks, to as little as 5.35% by July 19.

Authorities cited this trend as evidence that Gurugram is past its first epidemiological ‘peak’ of the outbreak.

Health department officials, including the district’s chief medical officer, compared the district’s trajectory of infection to that of larger metropolitan cities, which experts now believe are past their peaks.

“Delhi and Mumbai too have seen almost simultaneous dips in their growth rate and positivity rates. In terms of the severity of the outbreak, Gurugram’s absolute numbers are not that high, but we also have a population that’s 20 times less than Delhi’s. We have seen the same trend in terms of how the epidemic has progressed, but at a smaller scale,” said Dr Virender Yadav, chief medical officer(CMO), Gurugram, adding that transmission of the virus itself has been halted to a significant degree.

The challenge ahead lies in sustaining the prevailing positivity rate so that normal life can resume, albeit with strict social distancing measures. The WHO’s recommendation for lifting curbs on mobility is a daily TPR of five percent or less, over a period of at least two weeks.

“We are confident of being able to meet this benchmark, but it means that we cannot falter

on testing at all now, otherwise it will skew the progress that we are witnessing. The second thing is social distancing, which is more important for people to understand. The pandemic is not over. Our behaviour still needs to be vigilant,” said Dr Ram Prakash, district epidemiologist, Gurugram.

Cumulatively, a total of 8.6% of all samples tested from the district have come out positive for the SARS-Cov-2 virus.

This, officials said, is an improvement from about 17% in mid-June, while Gurugram’s peak was underway. While other cities like Delhi and Mumbai have since released comprehensive serological studies mapping the prevalence of Covid-19 among the community, a similar analysis for Gurugram is awaited.

While at least 361 IgG antibodies tests were conducted last month — on subjects belonging to 18 vulnerable demographic categories specified by the ICMR — only 25 of them (or 7%) were found to be seropositive.

“This is still a small sample. We will be able to make a concrete statement on prevalence and infection fatality rate once a wider study is done,” Dr Jai Prakash Sharma said.

Delhi and Mumbai too have seen almost simultaneous dips in their growth rate and positivity rate... We have seen the same trend in terms of how the epidemic has progressed, but at a smaller scale.

DR VIRENDER YADAV, CMO