Global search

Find data and evidence

Type at least 2 characters. Use arrow keys to review and Enter to open.

Peer reviewedOpen accessCOVID-19SARS

Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship, Yokohama, Japan, 2020

Eurosurveillance·

Kenji Mizumoto, Katsushi Kagaya, Alexander Zarebski, Gerardo Chowell

DOI
10.2807/1560-7917.es.2020.25.10.2000180
PMID
32183930
PMCID
PMC7078829
OpenAlex
W3010781325
Study type
Journal article
Publisher
European Centre for Disease Control and Prevention (ECDC)
Article type
journal-article
Integrity
current

Why this research matters now

The findings provide early empirical evidence on asymptomatic COVID-19 transmission in a closed setting, relevant to outbreak investigation and transmission dynamics during the early pandemic phase.

01

Structured evidence summary

Research question

The study aimed to estimate the asymptomatic proportion of COVID-19 infections among passengers and crew aboard the Diamond Princess cruise ship during its February 2020 quarantine in Yokohama, Japan.

Study design

Statistical modeling was applied to testing data from the quarantined cruise ship to derive delay-adjusted estimates of asymptomatic infection proportion and the timeline of infections.

Population and setting

The study population consisted of 3,711 people aboard the Diamond Princess cruise ship during a 2-week quarantine starting February 5, 2020, in Yokohama, Japan. By February 20, 634 individuals had tested positive for SARS-CoV-2.

Main findings

The delay-adjusted asymptomatic proportion of infections was estimated at 17.9% (95% credible interval: 15.5-20.2%). The modeling indicated that most infections occurred before the quarantine commenced.

Public-health relevance

The findings provide early empirical evidence on asymptomatic COVID-19 transmission in a closed setting, relevant to outbreak investigation and transmission dynamics during the early pandemic phase.

Important limitations

This summary is limited to the supplied single-article abstract and metadata. Full interpretation of model assumptions, testing coverage, generalizability beyond cruise ship settings, and confidence interval derivation requires access to the original paper.

GIDS interpretation

This peer-reviewed journal article from March 2020 would be discoverable through disease classifiers for COVID-19 and SARS, geographic filters for Japan, and topic tags for outbreak investigation, transmission dynamics, and travel medicine. It represents early pandemic research on asymptomatic transmission.

02

Related GIDS surveillance

Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.

03

Evidence relationships

This article has 13 auditable classifier relationships to diseases, places, topics, and study design.

about diseaseabout diseaseaddresses topicaddresses topicaddresses topichas pathogen typestudied instudied population settingstudies pathogenstudies populationstudies populationstudies populationuses study design