Significance On February 5, 2020, the Diamond Princess cruise ship was put under quarantine offshore Yokohama, Japan, after a passenger who disembarked in Hong Kong was confirmed to have coronavirus disease 2019. Whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and a network/phylogeny analysis of the outbreak suggested that there was a single introduction of SARS-CoV-2, which disseminated among passengers on the ship through possible mass-gathering events in the recreational areas. These findings provide information useful for preventing future outbreaks on cruise ships and emphasize the importance of genome-based network/phylogeny analysis to elucidate possible transmission routes in outbreak situations. The Diamond Princess cruise ship was put under quarantine offshore Yokohama, Japan, after a passenger who disembarked in Hong Kong was confirmed as a coronavirus disease 2019 case. We performed whole-genome sequencing of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) directly from PCR + clinical specimens and conducted a phylogenetic analysis of the outbreak. All tested isolates exhibited a transversion at G 11083 T, suggesting that SARS-CoV-2 dissemination on the Diamond Princess originated from a single introduction event before the quarantine started. Although further spreading might have been prevented by quarantine, some progeny clusters could be linked to transmission through mass-gathering events in the recreational areas and direct transmission among passengers who shared cabins during the quarantine. This study demonstrates the usefulness of haplotype network/phylogeny analysis in identifying potential infection routes.
【저자키워드】 COVID-19, SARS-CoV-2, haplotypes,