Browsing by Author "Leite, Ricardo"
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- Massive dissemination of a SARS-CoV-2 Spike Y839 variant in PortugalPublication . Borges, Vítor; Isidro, Joana; Cortes-Martins, Helena; Duarte, Sílvia; Vieira, Luís; Leite, Ricardo; Gordo, Isabel; Caetano, Constantino P.; Nunes, Baltazar; Sá, Regina; Oliveira, Ana; Guiomar, Raquel; Portuguese network for SARS-CoV-2 genomics (Consortium); Pinto, M. Alice; Rodrigues, CarinaGenomic surveillance of SARS-CoV-2 was rapidly implemented in Portugal by the National Institute of Health in collaboration with a nationwide consortium of >50 hospitals/laboratories. Here, we track the geo-temporal spread of a SARS-CoV-2 variant with a mutation (D839Y) in a potential host-interacting region involving the Spike fusion peptide, which is a target motif of anti-viral drugs that plays a key role in SARS-CoV-2 infectivity. The Spike Y839 variant was most likely imported from Italy in mid-late February and massively disseminated in Portugal during the early epidemic, becoming prevalent in the Northern and Central regions of Portugal where it represented 22% and 59% of the sampled genomes, respectively, by 30 April. Based on our high sequencing sampling during the early epidemics [15.5% (1275/8251) and 6.0% (1500/24987) of all confirmed cases until the end of March and April, respectively], we estimate that between 14 March and 9 April (covering the epidemic exponential phase) the relative frequency of the Spike Y839 variant increased at a rate of 12.1% (6.1%–18.2%, CI 95%) every three days, being potentially associated with 24.8% (20.8–29.7%, CI 95%; 3177–4542 cases, CI 95%) of all COVID-19 cases in Portugal during this period. Our data support population/epidemiological (founder) effects contributing to the Y839 variant super spread. The potential existence of selective advantage is also discussed, although experimental validation is required. Despite huge differences in genome sampling worldwide, SARS-CoV-2 Spike D839Y has been detected in 13 countries in four continents, supporting the need for close surveillance and functional assays of Spike variants.
- SARS-CoV-2 introductions and early dynamics of the epidemic in PortugalPublication . Borges, Vítor; Isidro, Joana; Trovão, Nídia Sequeira; Duarte, Sílvia; Cortes-Martins, Helena; Martiniano, Hugo; Gordo, Isabel; Leite, Ricardo; Vieira, Luís; Portuguese network for SARS-CoV-2 genomics (Consortium); Pinto, M. Alice; Rodrigues, CarinaGenomic surveillance of SARS-CoV-2 in Portugal was rapidly implemented by the National Institute of Health in the early stages of the COVID-19 epidemic, in collaboration with more than 50 laboratories distributed nationwide. Methods By applying recent phylodynamic models that allow integration of individual-based travel history, we reconstructed and characterized the spatio-temporal dynamics of SARSCoV-2 introductions and early dissemination in Portugal. Results We detected at least 277 independent SARS-CoV-2 introductions, mostly from European countries (namely the United Kingdom, Spain, France, Italy, and Switzerland), which were consistent with the countries with the highest connectivity with Portugal. Although most introductions were estimated to have occurred during early March 2020, it is likely that SARS-CoV-2 was silently circulating in Portugal throughout February, before the first cases were confirmed. Conclusions Here we conclude that the earlier implementation of measures could have minimized the number of introductions and subsequent virus expansion in Portugal. This study lays the foundation for genomic epidemiology of SARS-CoV-2 in Portugal, and highlights the need for systematic and geographically-representative genomic surveillance.