Multiple clades of SARS-CoV-2 were introduced to Thailand during the first quarter of 2020

Abstract

In early January 2020, Thailand became the first country where a coronavirus disease 2019 (COVID-19) patient was identified outside China. In this study, 23 whole genomes of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) from patients who were hospitalized from January to March 2020 were analyzed, along with their travel histories. Six lineages were identified including A, A.6, B, B.1, B.1.8, and B.58, among which lineage A.6 was dominant. Seven patients were from China who traveled to Thailand in January and early February. Five of them were infected with the B lineage virus, and the other two cases were infected with different lineages including A and A.6. These findings present clear evidence of the early introduction of diverse SARS-CoV-2 clades in Thailand.

Keywords: SARS-CoV-2; Thailand; clade; diverse; early.

Figure 1

Sequencing data were uploaded to Nextclade (https://clades.nextstrain.org/, accessed on April 4, 2020) for phylogenetic analysis. Thai sequences (n = 243) from specimens sampled before March 31, 2020, were downloaded from the GISAID database on November 13, 2020, including the genomes from this study (n = 23). Colored circles show the sequencing data obtained in this analysis. Five Nextstrain clades were indicated; 19A (purple color), 19B (dark blue), 20A (blue), 20B (emerald green), and 20C (leaf green). The new GV GISAID clades (20E. EU1 Nextstrain clade) found in Thailand in October 2020 is in lime green circle [Color figure can be viewed at wileyonlinelibrary.com]