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Identification and monitoring of SARS-CoV-2 Variants of Concern/Interest (VOC/VOIs) is essential to guide public health measures. We report the surveillance of VOCs circulating in Karachi during the pandemic between April 2021 and February 2022. We screened 2150 SARS-CoV-2 PCR positive samples received at the AKUH Clinical Laboratories. VOC was identified using a PCR-based approach targeting lineage-specific mutations using commercially available assays. Of the SARS-CoV-2 PCR positive samples, 81.7% had VOC/VOI, while 18.3% were undetermined. Alpha variants were predominant at 82.5% and 40.3% of the cases in April and May 2021. Beta variants increased in May (29%) and June (42%) and then reduced to 6% by July. Gamma variant cases were at 14.5% and 9% in May and June, respectively. Delta variants first detected in May, increased to comprise 66% of all variants by July, remaining dominant in August, September, October, and November 2021 at 88%, 91%, 91% and 85% respectively. Omicron (BA.1) variants emerged in December, rising to 42% of cases with an increase to 81% by January 2022 and then reducing to 45% in February 2022. Delta variant prevalence was coincident with increased hospital admissions and mortality. The Omicron variant surge was associated with increased daily infections but limited COVID-19 severity. We highlight the predominance of the VOCs identified through a rapid PCR based approach. As this is important to inform a public health response, we propose that a mutation targeted approach can be a rapid, lower cost solution to aid tracking of known VOCs during pandemic waves.
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ObjectivesPakistan has a high infectious disease burden with about 265,000 reported cases of COVID-19. We investigated the genomic diversity of SARS-CoV-2 strains and present the first data on viruses circulating in the country. MethodsWe performed whole-genome sequencing and data analysis of SARS-CoV-2 eleven strains isolated in March and May. ResultsStrains from travelers clustered with those from China, Saudi Arabia, India, USA and Australia. Five of eight SARS-CoV-2 strains were GH clade with Spike glycoprotein D614G, Ns3 gene Q57H, and RNA dependent RNA polymerase (RdRp) P4715L mutations. Two were S (ORF8 L84S and N S202N) and three were L clade and one was an I clade strain. One GH and one L strain each displayed Orf1ab L3606F indicating further evolutionary transitions. ConclusionsThis data reveals SARS-CoV-2 strains of L, G, S and I have been circulating in Pakistan from March, at the start of the pandemic. It indicates viral diversity regarding infection in this populous region. Continuing molecular genomic surveillance of SARS-CoV-2 in the context of disease severity will be important to understand virus transmission patterns and host related determinants of COVID-19 in Pakistan.
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COVID-19 caused by SARS-CoV-2 manifests as a range of symptoms. Understanding the molecular mechanisms responsible for immuno-pathogenesis of disease is important for treatment and management of COVID-19. We examined host transcriptomes in moderate and severe COVID-19 cases with a view to identifying pathways that affect its progression. RNA extracted from whole blood of COVID-19 cases was analysed by microarray analysis. Moderate and severe cases were compared with healthy controls and differentially regulated genes (DEGs) categorized into cellular pathways. DEGs in COVID-19 cases were mostly related to host immune activation and cytokine signaling, pathogen uptake, host defenses, blood and vasculature genes, and SARS-CoV-2- and other virus-affected pathways. The DEGs in these pathways were increased in severe compared with moderate cases. In a severe COVID-19 patient with an unfavourable outcome we observed dysregulation of genes in platelet homeostasis and cardiac conduction and fibrin clotting with disease progression. COVID-19 morbidity is associated with cytokine activation, cardiovascular risk and thrombosis. We identified DEGs related to dysregulation of blood clotting and homeostasis, platelet activation pathways and to be associated with disease progression. These can be biomarkers of disease progression and also potential targets for treatment interventions in COVID-19.
