TY - JOUR
T1 - SARS-CoV-2 infections among Australian passengers on the Diamond Princess cruise ship
T2 - A retrospective cohort study
AU - Walker, Liz J.
AU - Codreanu, Tudor A.
AU - Armstrong, Paul K.
AU - Goodwin, Sam
AU - Trewin, Abigail
AU - Spencer, Emma
AU - Colquhoun, Samantha M.
AU - Stephens, Dianne M.
AU - Baird, Rob W.
AU - Douglas, Nicholas M.
AU - Cribb, Danielle
AU - Owen, Rhonda
AU - Kelly, Paul
AU - Kirk, Martyn D.
N1 - Funding Information:
We thank members of the Australian Medical Assistance Team (AUSMAT), the National Critical Care and Trauma Response Centre (NCCTRC) and the National Incident Room who conducted the repatriation, quarantine and interviewing of the passengers. We also thank the research officers at the National Centre for Epidemiology & Population Health who entered data into REDCap and the Japanese National Focal Point for providing the Diamond Princess manifest of Australian nationals and in-country testing outcomes. We especially thank the Australian passengers of the Diamond Princess without whose cooperation this investigation could not have been conducted.
Publisher Copyright:
© 2021 Walker et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
PY - 2021/9
Y1 - 2021/9
N2 - Background Prolonged periods of confined living on a cruise ship increase the risk for respiratory disease transmission. We describe the epidemiology and clinical characteristics of a SARS-CoV-2 outbreak in Australian passengers on the Diamond Princess cruise ship and provide recommendations to mitigate future cruise ship outbreaks. Methods We conducted a retrospective cohort study of Australian passengers who travelled on the Diamond Princess from 20 January until 4 February 2020 and were either hospitalised, remained in Japan or repatriated. The main outcome measures included an epidemic curve, demographics, symptoms, clinical and radiological signs, risk factors and length of time to clear infection. Results Among 223 Australian passengers, 56 were confirmed SARS-CoV-2 positive. Forty-nine cases had data available and of these over 70% had symptoms consistent with COVID-19. Of symptomatic cases, 17% showed signs and symptoms before the ship implemented quarantine and a further two-thirds had symptoms within one incubation period of quarantine commencing. Prior to ship-based quarantine, exposure to a close contact or cabin mate later confirmed SARS-CoV-2 positive was associated with a 3.78 fold (95% CI, 2.24-6.37) higher risk of COVID-19 acquisition compared to non-exposed passengers. Exposure to a positive cabin mate during the ship's quarantine carried a relative risk of 6.18 (95% CI, 1.96-19.46) of developing COVID-19. Persistently asymptomatic cases represented 29% of total cases. The median time to the first of two consecutive negative PCR-based SARSCoV- 2 assays was 13 days for asymptomatic cases and 19 days for symptomatic cases (p = 0.002). Conclusion Ship based quarantine was effective at reducing transmission of SARS-CoV-2 amongst Australian passengers, but the risk of infection was higher if an individual shared a cabin or was a close contact of a confirmed case. Managing COVID-19 in cruise ship passengers is challenging and requires enhanced health measures and access to onshore quarantine and isolation facilities.
AB - Background Prolonged periods of confined living on a cruise ship increase the risk for respiratory disease transmission. We describe the epidemiology and clinical characteristics of a SARS-CoV-2 outbreak in Australian passengers on the Diamond Princess cruise ship and provide recommendations to mitigate future cruise ship outbreaks. Methods We conducted a retrospective cohort study of Australian passengers who travelled on the Diamond Princess from 20 January until 4 February 2020 and were either hospitalised, remained in Japan or repatriated. The main outcome measures included an epidemic curve, demographics, symptoms, clinical and radiological signs, risk factors and length of time to clear infection. Results Among 223 Australian passengers, 56 were confirmed SARS-CoV-2 positive. Forty-nine cases had data available and of these over 70% had symptoms consistent with COVID-19. Of symptomatic cases, 17% showed signs and symptoms before the ship implemented quarantine and a further two-thirds had symptoms within one incubation period of quarantine commencing. Prior to ship-based quarantine, exposure to a close contact or cabin mate later confirmed SARS-CoV-2 positive was associated with a 3.78 fold (95% CI, 2.24-6.37) higher risk of COVID-19 acquisition compared to non-exposed passengers. Exposure to a positive cabin mate during the ship's quarantine carried a relative risk of 6.18 (95% CI, 1.96-19.46) of developing COVID-19. Persistently asymptomatic cases represented 29% of total cases. The median time to the first of two consecutive negative PCR-based SARSCoV- 2 assays was 13 days for asymptomatic cases and 19 days for symptomatic cases (p = 0.002). Conclusion Ship based quarantine was effective at reducing transmission of SARS-CoV-2 amongst Australian passengers, but the risk of infection was higher if an individual shared a cabin or was a close contact of a confirmed case. Managing COVID-19 in cruise ship passengers is challenging and requires enhanced health measures and access to onshore quarantine and isolation facilities.
UR - http://www.scopus.com/inward/record.url?scp=85114459751&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0255401
DO - 10.1371/journal.pone.0255401
M3 - Article
AN - SCOPUS:85114459751
VL - 16
SP - 1
EP - 12
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 9 September
M1 - e0255401
ER -