Comparison of First and Second Waves of COVID-19 in Metropolitan Chennai City

The study aims to perform a comparative analysis of new cases of COVID-19 reported during the peak time of two waves in Chennai city in 2019–2020. Eight zone-wise variables for 15 zones of Chennai City were studied. They were reduced to fewer factors using a dimension reduction technique called factor analysis, and a standardized index value for each zone and two waves was obtained. The region of hot spots was identified using the Kriging interpolation method using the standardized index value. During wave 1, the average daily number of deaths, new cases, and active cases was 37, 2071, and 21163, respectively, but it was 76, 6663, and 39385 in the second wave. The second wave has a two times higher number of deaths, 3.2 times higher number of new cases, and 1.8 times of active cases. The first wave had a higher percentage of infected people aged 40 years or older, whereas it was more people aged 10–39 years in the second wave. The Krigged estimates showed comparison showed the regions at a higher risk of COVID-19 transmission. Population demographics play a vital role. The zone with a more slum population (Sholiganallur) does not show much intensity of new cases.