Burden of COVID-19 and Case Fatality Rate in Pune India: An Analysis of First and Second Wave of the Pandemic

Background The recent second wave in India in April-May 2021 placed an unprecedented burden on the Indian health systems. However, limited data exist on the epidemiology of the COVID-19 pandemic from the first wave through the second wave in India. With detailed epidemiologic data, we aimed to assess trends in incident cases and case fatality, its risk between pandemic waves in Pune, an epicenter of COVID-19 cases in India, a country with the second-largest absolute burden worldwide. Methods Programmatic COVID-19 data from Pune city between the first wave (March 09 th 2020-October 31 st , 2020), maintenance phase (November 01 st 2020-February 14 th , 2021), the second wave (February 15 th , 2021-May 31 st , 2021) were assessed for trends of incident cases, time-to-death, and case fatality rate (CFR). In addition, Poisson regression models adjusted for age and gender were used to determine the independent effect of pandemic waves on mortality. Results Of 465,192 COVID-19 cases, 162,182 (35%) were reported in the first wave, and 4,146 (2.5%) died among them; Maintenance period registered 27,517 (6%) cases with 590 (2.1%) deaths; Second wave reported 275,493 (59%) cases and 3184 (1.1%) deaths (p<0.01). The overall CFR was 1.16 per 1000 person-days (PD), which declined from 1.80 per 1000 PD during the first wave to 0.77 per 1000 PD in the second wave. The risk of death was 1.49 times higher during the first wave (adjusted case fatality rate ratio-aCFRR,1.49; 95% CI: 1.37–1.62) and 35% lower in the second wave (aCFRR, 0.65; 95% CI: 0.59 – 0.70), compared to the maintenance phase. Interpretation The absolute burden of COVID-19 cases and deaths were more significant in the second wave in Pune, India; however, the CFR declined as the pandemic progressed. Nevertheless, investigating newer therapies and implementing mass vaccinations against COVID-19 are urgently needed.