Epidemiology of Coronavirus Disease Outbreak among Crewmembers on Cruise Ship, Nagasaki City, Japan, April 2020

Abstract

S evere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was fi rst reported from Wuhan, China (1), and led to outbreaks of coronavirus disease (COVID-19), which was declared a pandemic by the World Health Organization on March 11, 2020. COVID-19 also has been affecting global economies, leading to several recessions (2). Japan experienced an outbreak of COVID-19 on the cruise ship Diamond Princess during the early stages of the epidemic in February 2020 (3-5). The government of Japan prohibited entry into the country at the end of March, declaring a state of emergency in 7 prefectures on April 7, which became a nationwide policy on April 16. Against this backdrop, the Italian cruise ship Costa Atlantica had remained docked at Nagasaki City since January 2020 for full maintenance. In April 2020, we identifi ed an outbreak of COVID-19 on this cruise ship.COVID-19 spreads easily on cruise ships because of the "3 Cs": crowded places, close-contact settings, and confi ned and enclosed spaces (6-9). Given the specialized setting of a cruise ship and its closed population, a cruise ship can offer important insights about infectious disease epidemiology and transmission dynamics (10). How to manage an outbreak of COVID-19 on a cruise ship is a matter of debate, especially in a resource-limited situation. To improve our understanding of COVID-19 and prepare for outbreaks to come, studies of outbreaks on cruise ships are valuable. In this article we describe the epidemiology of the COVID-19 outbreak on Costa Atlantica and approaches taken for managing and responding to this outbreak.

Exploring spatiotemporal patterns of COVID-19 infection in Nagasaki Prefecture in Japan using prospective space-time scan statistics from April 2020 to April 2022

“…The first COVID-19 case in Nagasaki Prefecture was reported on Iki Island on March 14, 2020. The most challenging situation in Period 1 occurred on the foreign cruise that anchored near the quay of Nagasaki harbor in April [ 25 ]. The prospective space-time scan statistic identified four clusters with statistical significance ( p < 0.05), shown in Fig.…”

Unique Evolution of SARS-CoV-2 in the Second Large Cruise Ship Cluster in Japan

“…The present study investigated the evolution of SARS-CoV-2 strains in the second large cruise ship cluster in Japan on the Costa Atlantica (CA). Recently, an epidemiological study revealed the relationships of SARS-CoV-2 infections with age, occupation, underlying diseases, symptoms, and cabin room location on the CA cruise ship [18]. In this previous study, the first case of a body temperature >37.1 • C was identified on 22 March 2020, in a crew member who belonged to the entertainment group that boarded the CA cruise ship from Europe on March 18 or 19 [18].…”

“…Recently, an epidemiological study revealed the relationships of SARS-CoV-2 infections with age, occupation, underlying diseases, symptoms, and cabin room location on the CA cruise ship [18]. In this previous study, the first case of a body temperature >37.1 • C was identified on 22 March 2020, in a crew member who belonged to the entertainment group that boarded the CA cruise ship from Europe on March 18 or 19 [18]. Our BLAST analysis using the sequences of CA strains located at the root in the phylogenetic tree revealed that the possible origin of CA strains was derived from European countries, showing a high consistency of our results with the previous study.…”

“…Of all 712 COVID-19 positive individuals, 17.9% were estimated to be asymptomatic in the DP cluster [13]. Interestingly, 35.6% of COVID-19 positive cases were asymptomatic in the CA cluster, indicating that more asymptomatic individuals were related with the spread of the virus in the CA cruise ship than in DP [18]. Moreover, a recent study provided evidence that at least 50% of SARS-CoV-2 transmission is caused by asymptomatic individuals [31].…”

Analysis of the on-ship transmission of the COVID-19 mass outbreak on the Republic of Korea Navy amphibious warfare ship

“…'20년 1월 코로나19 판데믹 이후, 전세계적으로 교육시설, 종교시설, 목욕탕 및 음식점 등 다중이용시설, 병원 및 사업장 등 다양한 장소와 경로를 통한 집단 사례 발생이 보고되고 있 다 [3][4]. 코로나19에 의한 다양한 집단 사례 중 선박에서의 코로나19 집단 발병은 일본에서 2020 년 2월 중순 탑승자 700여 명이 감염된 D사의 크루즈선 사례가 있으며, 이후 미국 G사의 크루즈 선, 브라질의 화물선 등의 사례가 보고되었으며 [5][6][7], 특히 항공 모함(aircraft carrier)을 비롯한 군 함에서의 코로나19 집단 사례 [8][9] The adjusted rate ratio was calculated using the Mantel-Haenszel method, which is a weighted average of crude rate ratios from the individual stratumspecific two-by-two tables. 3 Due to the high correlation between age and rank, it was excluded from the calculation of adjusted rate ratio.…”