SARS-CoV-2 clearance in term of Cycle Threshold (Ct) during first two waves of COVID-19 in Pakistan: a phenomenon of delayed viral clearance post-corticosteroid treatment

Abstract

SARS-CoV-2 is recently emerged virus, which caused millions of deaths, all over the world. To tackle COVID-19 pandemic, there is an utmost need for in-depth analysis of viral replication. We aimed to examine viral load in SARS-CoV-2 patients during first two waves of COVID-19 in Pakistan. 225,615 suspected subjects from 75 different regions of Pakistan were selected in the study. SARS-CoV-2 RNAs were detected via real time PCR. During first wave (period of June-July, 2020) of COVID-19 the prevalence of SARS-CoV-2 was 20.38%. However, during second wave (period of November-December, 2020) of COVID-19, the rate of prevalence was 9.41%. During first wave of COVID-19 96.31% of participants remained PCR positive for 14 to 21 days, 3.39% of subjects showed positive results for 22 to 35 days, while delayed Ct values were observed among 0.26% of participants for 36 to 49 days. However, during second wave of COVID-19 89.31% of the subjects exhibited symptoms and showed real-time PCR positive results for 14 to 21 days, 9.42% showed positive results for 22 to 35 days, while significantly delayed Ct value results were observed among 1.026% of participants for 36 to 63 days (3.95 times higher than first wave). In contrast to first wave of COVID-19, the factors that were different in second wave were neither viral (different strains) nor host (same population). But treatment factors changed significantly. As during second wave besides azithromycin, corticosteroid dexamethasone consumption was increased consequently causing delayed Ct value negativity. This suggests that corticosteroid treatment might be linked with delayed Ct value or viral clearance. This study is crucial for re-considering effective therapeutic options against COVID-19.