Comparative Analysis of Epidemiological & Clinical Trends Across the First, Second and Third Waves of COVID-19: Insights from a Tertiary Care Hospital

Abstract

Background: The COVID-19 pandemic has unfolded in multiple waves, each marked by unique transmission patterns and clinical outcomes. In India, three notable waves occurred from October 2020 to December 2022, recognized globally for their variation in disease severity, demographic impact, and healthcare demands. Examining these variations is essential for developing targeted healthcare responses and improving preparedness for future infectious disease surges.

Aim: This study compares the clinical characteristics, epidemiological factors, and impact of COVID-19 patients admitted during the first, second, and third waves of the pandemic at Integral Institute of Medical Sciences and Research (IIMSR), Integral Hospital, a tertiary care hospital in Lucknow, India.

Methods: This prospective study conducted a comparative epidemiological analysis of COVID-19 patient admissions across three distinct SARS-CoV-2 waves at Integral Institute of Medical Sciences and Research (IIMSR), Integral Hospital, a tertiary care hospital in Lucknow, India.: the first wave (Oct-Dec 2020), the second wave (March–May 2021), and the third wave (January–February 2022). A total of 6,732 COVID-19 tests were performed, resulting in 1,196 confirmed positive cases by RT-PCR included for analysis. Clinical data on risk factors, demographical variables, age, gender, vaccination status, laboratory results, and in-hospital outcomes were gathered from the ICMR Specimen referral form.

Results: From 6793 real-time quantitative PCR (qRT-PCR) tests assessed, the selected 1,196 positive diagnostics showed a decrease in case fatality rate in the second wave (10.31%) compared with the first (5.95%) while no deaths were recorded in the third wave, suggesting decreased severity as the pandemic progressed. The second wave had the highest case count with 970 confirmed cases and a positivity rate of 30.8%.

Conclusion: The second wave of COVID-19 presented the most severe clinical outcomes among the three waves. Co-morbid conditions contributed to increased mortality rates, especially in second wave, underscoring the need for targeted healthcare strategies in managing high-risk patients during pandemic waves. Understanding these distinctions offers valuable insights into the disease’s progression in a specific regional context and highlights factors influencing patient outcomes across different pandemic stages.