A measure for Covid-19 distress

Covid-19 progresses roughly according to a logistical law-exponentially at first till a peak rate is reached and then the curve turns and finally levels off. In this correspondence, we identify two components-the death rate per million of population (N) and the fractional rate of change (f) at each stage. We propose a second-order indicator X = f 2 N as a single number metric summarising the criticality of the rate of progress of the pandemic at that stage. We use as example, the progress of Covid-19 within India, and show that Kerala is the state with the highest distress as the New Year turns in. Keywords Covid-19 · SARS-CoV-2 virus · death rates per million · doubling time · fractional rate of change · second-order indicator