COVID-19 cryptic transmission and genetic information blackouts: Need for effective surveillance policy to better understand disease burden

Abstract

We read with interest on the case of SARS-CoV-2 re-infection on the importance of genomic information in understanding the true burden of COVID-19 [1]. After the emergence of SARS-CoV-2 in China, initial cases in Japan were travel-associated cases from affected areas, as determined by the viral sequence analyses. In concordance with global COVID-19 epidemic, the Asian SARS-CoV-2 clades were dominant until the beginning of March, 2020 [2]. However, as of April, with the emergence of European clades (20A, 20B, 20C) as the dominant clade in Japan, there were no reports on local transmission of the Asian clades (19A and 19B) within the following weeks (figure).