Comparison of Cycle Threshold and Clinical Status Among Different Age Groups of COVID-19 Cases

PURPOSE: Aim of the study was to compare the viral load and clinical status among different age groups with COVID-19 infection METHODS & MATERIALS: A retrospective cross-sectional study was carried out to analyse the Ct values of positive samples reported during April 2020 till May 2021. Result of 13,820 number of RT-PCR positive samples were included for analysis of Ct values. Ct values of confirmatory genes were taken into consideration and Ct values below 25, >25 to 30 and >30 was categorized as high, moderate and low viral load respectively. Age group was stratified into ≤18 years, 18-60 and >60 years as young, adult and elderly respectively. The data was analysed using SPSS windows version 25.0. RESULTS: The Mean Ct value was 27.9, 26, and 26.2 in young, adult and elderly age group respectively. Mean Ct value of young patients were significantly higher as compared to adult and elderly patients (p<0.05). The percentage of high viral load (Ct<25) was found to be significantly higher in adults and elderly (44.6% & 43.7%) as compared to young (32.2%) (p<0.001). Majority of the covid 19 positive cases belonging to <18 years age (75.9%) were asymptomatic as compared to 64.5% and 59.7% in adult and elderly age groups respectively. CONCLUSION: Present study observed a significantly high proportion of viral load in the adult and elderly population which plays a substantial contribution to SARS CoV-2 transmission, whereas the majority of the young population being asymptomatic play major role as silent transmitters. The study reemphasizes the need for strict adherence to COVID appropriate behaviours.