Coronavirus (COVID-19): Among the measures for assessing the spread of an infection, one is test positivity rate — the proportion of positive cases among all tests done. It is taken to be a useful indicator if a substantial section of suspected cases has been tested.
From data on tests for COVID-19 and positive cases between March 18 and April 13, it emerges that the test positivity rate in India has been between 1.1% and 4.3% (ratios based on cumulative counts until any date). On April 9, the Indian Council of Medical Research (ICMR) said the positivity rate had not changed substantially over the last one to two months, maintaining between 3% and 5%.
In an outlier, the rate was 4.68% on April 3. That day, The Indian Express reported the Tablighi Jamaat congregation in Delhi accounted for one-fifth of the COVID-19 positive cases nationwide. Since then, the rate has remained around 4% — meaning about two in every 50 tests is positive.
Over 21,000 tests were conducted on April 13, and between 16,000 and 17,000 on the five preceding days. “If we are testing more and the positivity rate remains the same, it’s a clue that the infection is where it was and is not expanding per se. If you see that it suddenly goes up, that’s something that could be worrisome,” Tarun Bhatnagar, a scientist at ICMR and National Institute of Epidemiology, Chennai, said last week.
📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay updated with the latest headlines