On Tuesday, with 1,061 people testing Covid-positive of the 11,910 tests done, Delhi recorded a positivity rate of 8.9%. The last time the capital showed a similar positivity rate was July 20 when the positivity was 8.3%.
So, are infection levels once again rising in the city — they had fallen to a low of 5.1% on August 7— or is it a change in the kind of tests being done?
Delhi’s positivity levels started falling when it began conducting more Rapid Antigen Tests (RAT). From 21.4% on June 2, when there were no RAT tests, the positivity fell to 12.8% on June 30 by when the share of RAT had climbed to 45%; and on July 31, when RAT further increased to 70%, the positivity fell to 6.3%.
Positivity levels continued to fall thereafter, but as the share of RT-PCR has started to rise again, so has the positivity. Three weeks ago (August 4-10), just a fourth of tests were RT-PCR and less than six per cent of those being tested were found to be infected. That share of RT-PCR rose to about 32-33% in the August 18-24 period, and the positivity is also up to 7.3%.
