Coronavirus Disease 2019 (COVID-19) in Americans Aboard theDiamond PrincessCruise Ship

Abstract

Background The Diamond Princess cruise ship was the site of a large outbreak of coronavirus disease 2019 (COVID-19). Of 437 Americans and their travel companions on the ship, 114 (26%) tested positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Methods We interviewed 229 American passengers and crew after disembarkation following a ship-based quarantine to identify risk factors for infection and characterize transmission onboard the ship. Results The attack rate for passengers in single-person cabins or without infected cabinmates was 18% (58/329), compared with 63% (27/43) for those sharing a cabin with an asymptomatic infected cabinmate, and 81% (25/31) for those with a symptomatic infected cabinmate. Whole genome sequences from specimens from passengers who shared cabins clustered together. Of 66 SARS-CoV-2-positive American travelers with complete symptom information, 14 (21%) were asymptomatic while on the ship. Among SARS-CoV-2-positive Americans, 10 (9%) required intensive care, of whom 7 were ≥70 years. Conclusion Our findings highlight the high risk of SARS-CoV-2 transmission on cruise ships. High rates of SARS-CoV-2 positivity in cabinmates of individuals with asymptomatic infections suggest that triage by symptom status in shared quarters is insufficient to halt transmission. A high rate of intensive care unit admission among older individuals complicates the prospect of future cruise travel during the pandemic, given typical cruise passenger demographics. The magnitude and severe outcomes of this outbreak were major factors contributing to the Centers for Disease Control and Prevention’s decision to halt cruise ship travel in U.S. waters in March 2020.

The Bayesian Susceptible-Exposed-Infected-Recovered model for the outbreak of COVID-19 on the Diamond Princess Cruise Ship

“…Previous studies have suggested the heterogeneity in the cases on different decks and locations due to different transmission modes (Azimi et al 2020;Fang et al 2020;Plucinski et al 2020;Yamagishi et al 2020b). The fomite and aerosol transmission (van Doremalen et al 2020;Mallapaty 2020;Mizumoto and Cowell 2020;Nakazawa et al 2020), and meteorological factors (Cheng and Wang-Li 2019;Hsiao et al 2020;Lin et al 2020;Pang et al 2020;Pani et al 2020) have been reported to make respective contributions to the spread of SARS-CoV-2.…”

Systematic Review on Outbreaks of SARS-CoV-2 on Cruise, Navy and Cargo Ships

“…Overall, 27 studies were identified referring to the Diamond Princess. Eleven studies gave a descriptive epidemiology report of the outbreak of SARS-CoV-2 on the cruise ship [39][40][41][42][43][44][45][46][47][48][49] analyzing, e.g., the proportion of asymptomatic cases [39,[42][43][44][45][46][47][48][49]. Seven studies analyzed clinical outcomes or clinical courses [39,45,[50][51][52][53][54] e.g., with a special focus on conjunctivitis [53], lung opacities and airway abnormalities [39,52] or single patients [51].…”

Phylogenomic tracing of asymptomatic transmission in a COVID-19 outbreak

“…In the outbreak cluster, we observed that the asymptomatic carriers and minimally symptomatic patients (without fever) accounted for 35.7% and 28.6% of the cases (Table 1), respectively, which is consistent with previous studies. 16,17,24,25 It is worth noting that the four minimally symptomatic patients did not realize their SARS-CoV-2 infection and were missed by mandatory temperature checks. Therefore, when discussing prevention and control strategies for COVID-19, the minimally symptomatic carriers should be managed the same as asymptomatic cases.…”