Molecular Epidemiology of SARS-CoV-2 in Greece Reveals Low Rates of Onward Virus Transmission after Lifting of Travel Restrictions Based on Risk Assessment during Summer 2020
| Autor: | Meletios A. Dimopoulos, Panagiota Lourida, Dimitrios Chatzidimitriou, Spyridon Pournaras, Nikolaos Spanakis, Georgios Kollias, Fani Chatzopoulou, Georgios A. Pavlopoulos, Vaggelis Harokopos, Pantelis Hatzis, Athanasios Tsakris, Periklis Panagopoulos, Gkikas Magiorkinis, A. Hatzakis, Christos Hadjichristodoulou, Cleo Anastassopoulou, Dimitrios Paraskevis, Kleio-Maria Verrou, Gerasimos Gerolymatos, Spyros Sapounas, Aikaterini Argyraki, Sotirios Tsiodras, Vana Sypsa, Nikolaos Siafakas, Panagiotis Prezerakos, Theodoros Lytras, Georgios Panagiotakopoulos, Anastasia Kotanidou, Giannis Ampatziadis-Michailidis, Evangelia Georgia Kostaki, Petros P. Sfikakis, Panagiotis Moulos |
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| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
medicine.medical_specialty phylogeography medicine.disease_cause Microbiology molecular epidemiology law.invention 03 medical and health sciences 0302 clinical medicine law Pandemic medicine 030212 general & internal medicine Molecular Biology Coronavirus Phylogenetic tree Molecular epidemiology SARS-CoV-2 Public health public health QR1-502 Phylogeography travel restrictions 030104 developmental biology Geography Transmission (mechanics) Risk assessment human activities Contact tracing Demography Research Article |
| Zdroj: | mSphere mSphere, Vol 6, Iss 3 (2021) |
| ISSN: | 2379-5042 |
| Popis: | The novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spread rapidly during the first months of 2020 and continues to expand in multiple areas across the globe. Molecular epidemiology has provided an added value to traditional public health tools by identifying SARS-CoV-2 clusters or providing evidence that clusters based on virus sequences and contact tracing are highly concordant. Our aim was to infer the levels of virus importation and to estimate the impact of public health measures related to travel restrictions to local transmission in Greece. Our phylogenetic and phylogeographic analyses included 389 full-genome SARS-CoV-2 sequences collected during the first 7 months of the pandemic in Greece and a random collection in five replicates of 3,000 sequences sampled globally, as well as the best hits to our data set identified by BLAST. Phylogenetic trees were reconstructed by the maximum likelihood method, and the putative source of SARS-CoV-2 infections was inferred by phylogeographic analysis. Phylogenetic analyses revealed the presence of 89 genetically distinct viruses identified as independent introductions into Greece. The proportion of imported strains was 41%, 11.5%, and 8.8% during the three periods of sampling, namely, March (no travel restrictions), April to June (strict travel restrictions), and July to September (lifting of travel restrictions based on thorough risk assessment), respectively. The results of phylogeographic analysis were confirmed by a Bayesian approach. Our findings reveal low levels of onward transmission from imported cases during summer and underscore the importance of targeted public health measures that can increase the safety of international travel during a pandemic. IMPORTANCE Our study based on current state-of-the-art molecular epidemiology methods suggests that virus screening and public health measures after the lifting of travel restrictions prevented SARS-CoV-2 onward transmission from imported cases during summer 2020 in Greece. These findings provide important data on the efficacy of targeted public health measures and have important implications regarding the safety of international travel during a pandemic. Our results can provide a roadmap about prevention policy in the future regarding the reopening of borders in the presence of differences in vaccination coverage, the circulation of the virus, and the presence of newly emergent variants across the globe. |
| Databáze: | OpenAIRE |
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