As Covid-19 cases rise, testing in 4 most affected cities slowing

Better testing is key to identifying new areas of the surge before they turn into hotspots.

Scientists and doctors know more about Omicron a month after it was declared a coronavirus variant of concern and rapidly spreads across the world and Indian cities.

Test positivity rate--the percentage of all coronavirus tests that turn out to be positive --is rising in Mumbai, Pune, Delhi and Bengaluru, four of the most-affected cities. Here, weekly averages of confirmed cases and laboratory tests have been used to arrive at a weekly test positivity rate, which refers to the seven days prior to any particular date.

Mumbai, Delhi and Pune have shown a dramatic rise in the positivity rate in the