RESUMEN
OBJECTIVES: This study aimed to explore associations between the molecular characterization of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and disease severity in ambulatory and hospitalized patients in two main Colombian epicentres during the first year of the coronavirus disease 2019 pandemic. METHODS: In total, 1000 patients with SARS-CoV-2 infection were included in this study. Clinical data were collected from 997 patients, and 678 whole-genome sequences were obtained by massively parallel sequencing. Bivariate, multi-variate, and classification and regression tree analyses were run between clinical and genomic variables. RESULTS: Age >88 years, and infection with lineages B.1.1, B.1.1.388, B.1.523 or B.1.621 for patients aged 71-88 years were associated with death [odds ratio (OR) 6.048036, 95% confidence interval (CI) 1.346567-32.92521; P=0.01718674]. The need for hospitalization was associated with higher age and comorbidities. The hospitalization rate increased significantly for patients aged 38-51 years infected with lineages A, B, B.1.1.388, B.1.1.434, B.1.153, B.1.36.10, B.1.411, B.1.471, B.1.558 or B.1.621 (OR 8.368427, 95% CI 2.573145-39.10672, P=0.00012). Associations between clades and clinical outcomes diverged from previously reported data. CONCLUSIONS: Infection with lineage B.1.621 increased the hospitalization and mortality rates. These findings, plus the rapidly increasing prevalence in Colombia and other countries, suggest that lineage B.1.621 should be considered as a 'variant of interest'. If associated disease severity is confirmed, possible designation as a 'variant of concern' should be considered.