O-19 SARS-CoV-2 Variants and qRT-PCR Cycle Threshold Values
Author(s):
V Matthew-Belmar , N Noel , E Chitan , B Sharma , T Khan , N Cudjoe , B Osei Boakye , P Fields , T Noel , A Alhassan and CNL Macpherson
Type Of Study:
- Analytical Study
- Quantitative
Year of Presentation:
2022
Objective: SARS- CoV-2 has developed many variants that are responsible for causing the coronavirus pandemic over the past two years. Sequencing of the variants provides valuable clinical, epidemiological, and public health information. The aim of the study was to sequence positive SARSCoV-2 cases to examine the variants circulating in Grenada.
Methods: This study was conducted from the outbreaks of SARS-CoV-2 in Grenada during August/September 2021 and December/January 2022. Nasopharyngeal samples were obtained from persons stored on ice, transported to the laboratory and processed within a few hours using qRTPCR, targeting the E gene. Aliquots of samples were stored at –80. and sequencing was performed using the MinIon MK1C sequencing platform. Only samples with a Ct value of = 25 were included in the study.
Results: A total of 104 samples were sequenced (57 samples the from first wave, 47 from the second wave), variants were detected in 52 of these samples with their lineage. In the first wave, 20 samples (35.08%) were found to be the Delta variant (Ct values 11.3–21.15), whilst in the second wave, 32 samples (68.08%) were found to be of the Omicron variant (Ct values 11.57–24.66).
Conclusion: Our data demonstrates that the first wave of COVID-19 in Grenada was due to the Delta variant in August/September 2021 and by the Omicron variant in December/February 2022. It also confirms that the 2022 wave of infection in Grenada was due to the omicron variant; the same variant predominates globally