While Covid-19 cases continue to drop at a national level, data from some Indian states show the threat is still looming.
India’s overall 7-day daily average test positivity rate (TPR)—the percentage of all tests that come back positive—was 2% as of June 27 but in eight states, it was still over 5%, according to data shared by US-based epidemiologist Bhramar Mukherjee, who is the John D. Kalbfleisch collegiate professor of biostatistics at the University of Michigan.
Five of the states with higher TPRs were in the northeast, with Sikkim posting the highest at 16.3%, data show. Officials have attributed the high value to smaller sample size. Only “symptomatic patients and their primary contacts” are tested, the state’s health secretary Pempa T Bhutia said.
Why is the TPR crucial? Because it’s a benchmark for restrictions across states. According to Maharastra’s five-level unlock plan, for instance, after it crosses the 5% mark, offices, gyms, and restaurants have to operate at half capacity and can’t remain open post 4pm.
Besides the handful of states with higher TPRs, several others aren’t out of the weeds either. They could easily slip back into crisis, another indicator reveals.
Delta variant and Covid infection rates
To assess whether the infection is rising or subsiding, experts use the “R” value—a measure of how fast an infection spreads. An R number of one means one patient is infecting one other person on average. If the figure crosses one, there’s a chance the infection may snowball. And the second wave is proof that it will take no time for one state’s crisis to become a national one.
Right now, in over half a dozen states, the R-value was close to or more than one, Mukherjee found. In states like Maharashtra and Kerala, the R had come down to 0.4-0.5 but is now inching back up.
Maharashtra has been conservative about reopening in light of an impending third wave. In Mumbai, the capital of the state, authorities continued to implement level 3 restrictions even after its TPR dropped below 4% to err on the side of caution.
But most other states are not exercising caution.
In Mizoram, where the R-value was the highest at 1.29, the government is easing curbs for a partial opening. Other states in the northeast susceptible to a spike, like Assam and Nagaland, have gradually begun withdrawing restrictions. National capital Delhi, where the R-value was 0.99, has unlocked further this week.
Experts worry that the laxity, combined with an insufficient pace of vaccination, could spell trouble.
On June 29, Mukherjee warned the week-on-week rate of growth for Covid-19 cases is beginning to show a slight uptick in four states—Maharashtra, Kerala, Andhra Pradesh, and Delhi—and called for tighter restrictions in these places right away. She also said a vaccination rate of anything less than 10 million per day would be inadequate to shield the country from another wave.