Impact of the COVID-19 pandemic on levels of deep-ocean acoustic noise.

The extraordinary circumstances of the COVID-19 pandemic led to measures to mitigate the spread of the disease, with lockdowns and mobility restrictions at national and international levels. These measures led to sudden and sometimes dramatic reductions in human activity, including significant reductions in ship traffic in the maritime sector. We report on a reduction of deep-ocean acoustic noise in three ocean basins in 2020, based on data acquired by hydroacoustic stations in the International Monitoring System of the Comprehensive Nuclear-Test-Ban Treaty. The noise levels measured in 2020 are compared with predicted levels obtained from modelling data from previous years using Gaussian Process regression. Comparison of the predictions with measured data for 2020 shows reductions of between 1 and 3 dB in the frequency range from 10 to 100 Hz for all but one of the stations.

The contribution of asymptomatic SARS-CoV-2 infections to transmission on the Diamond Princess cruise ship.

A key unknown for SARS-CoV-2 is how asymptomatic infections contribute to transmission. We used a transmission model with asymptomatic and presymptomatic states, calibrated to data on disease onset and test frequency from the Diamond Princess cruise ship outbreak, to quantify the contribution of asymptomatic infections to transmission. The model estimated that 74% (70-78%, 95% posterior interval) of infections proceeded asymptomatically. Despite intense testing, 53% (51-56%) of infections remained undetected, most of them asymptomatic. Asymptomatic individuals were the source for 69% (20-85%) of all infections. The data did not allow identification of the infectiousness of asymptomatic infections, however low ranges (0-25%) required a net reproduction number for individuals progressing through presymptomatic and symptomatic stages of at least 15. Asymptomatic SARS-CoV-2 infections may contribute substantially to transmission. Control measures, and models projecting their potential impact, need to look beyond the symptomatic cases if they are to understand and address ongoing transmission.

Tracking the global reduction of marine traffic during the COVID-19 pandemic.

The COVID-19 pandemic has resulted in unparalleled global impacts on human mobility. In the ocean, ship-based activities are thought to have been impacted due to severe restrictions on human movements and changes in consumption. Here, we quantify and map global change in marine traffic during the first half of 2020. There were decreases in 70.2% of Exclusive Economic Zones but changes varied spatially and temporally in alignment with confinement measures. Global declines peaked in April, with a reduction in traffic occupancy of 1.4% and decreases found across 54.8% of the sampling units. Passenger vessels presented more marked and longer lasting decreases. A regional assessment in the Western Mediterranean Sea gave further insights regarding the pace of recovery and long-term changes. Our approach provides guidance for large-scale monitoring of the progress and potential effects of COVID-19 on vessel traffic that may subsequently influence the blue economy and ocean health.

Mechanistic transmission modeling of COVID-19 on the Diamond Princess cruise ship demonstrates the importance of aerosol transmission.

Several lines of existing evidence support the possibility of airborne transmission of coronavirus disease 2019 (COVID-19). However, quantitative information on the relative importance of transmission pathways of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains limited. To evaluate the relative importance of multiple transmission routes for SARS-CoV-2, we developed a modeling framework and leveraged detailed information available from the Diamond Princess cruise ship outbreak that occurred in early 2020. We modeled 21,600 scenarios to generate a matrix of solutions across a full range of assumptions for eight unknown or uncertain epidemic and mechanistic transmission factors. A total of 132 model iterations met acceptability criteria (R2 > 0.95 for modeled vs. reported cumulative daily cases and R2 > 0 for daily cases). Analyzing only these successful model iterations quantifies the likely contributions of each defined mode of transmission. Mean estimates of the contributions of short-range, long-range, and fomite transmission modes to infected cases across the entire simulation period were 35%, 35%, and 30%, respectively. Mean estimates of the contributions of larger respiratory droplets and smaller respiratory aerosols were 41% and 59%, respectively. Our results demonstrate that aerosol inhalation was likely the dominant contributor to COVID-19 transmission among the passengers, even considering a conservative assumption of high ventilation rates and no air recirculation conditions for the cruise ship. Moreover, close-range and long-range transmission likely contributed similarly to disease progression aboard the ship, with fomite transmission playing a smaller role. The passenger quarantine also affected the importance of each mode, demonstrating the impacts of the interventions.

Effects of COVID-19 on maritime industry: a review.

COVID-19 is a global disease that has quickly shaken the world economy since the beginning of 2020 and consequently has significantly affected the shipping industries development (including shipping operators, port operators, government authorities, shippers, seafarers, passengers, supply chain operators, etc.). Currently, the clinical management of COVID-19 remains unclear. In order to understand the newest challenges and figure out potential solutions for the maritime industries post COVID-19, this paper selected four shipping industries (including dry bulk, tanker, container, and cruiser sector) and reviewed these industries' newest development. The research findings can strengthen the awareness of COVID-19 and reduce operational risk and further improve business performance for the maritime related industries and authorities.

Telemedical assistance at sea in the time of COVID-19 pandemic.

BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the aetiological factor of COVID-19 infection, poses problems in providing medical assistance at sea. Ships are in an isolated environment, and most of the merchant ships do not carry medical personnel or medical supplies. Telemedicine offers a real possibility to provide reasonable quality medical assistance to seagoing vessels. The fact that ships may touch ports in affected areas, the difficulties for seafarers to be assisted ashore due to quarantine measures and the crews' lack of turnover make medical assistance at sea difficult. This study has compared maritime telemedical assistance data before and during the COVID-19 pandemic to propose prevention measures. MATERIALS AND METHODS: The study was based on the data from medical records of Centro Internazionale Radio Medico (C.I.R.M.) database of seafarers assisted from January 1 to June 30, in the years 2017-2020. The data were collected separately for each year. Age, sex, rank, and pathologies affecting the assisted seafarers were considered. Common signs of COVID-19 infection such as fever, cough, sore throat, shortness of breath, and other respiratory symptoms were analysed. RESULTS: From January 1, 2017, to December 31, 2019, C.I.R.M. assisted 15,888 patients on board ships. During the first 6 months of the years under evaluation, C.I.R.M. assisted 2,419 patients in 2017, 2,444 patients in 2018, 2,694 patients in 2019, and 3,924 in 2020. The number of assisted cases almost doubled in the first 6 months (from January to June) of 2020 compared to the same period of the previous years. Gastrointestinal disorders, injuries/traumas, and dermatological pathologies were the first, second, and third most often reported causes of illness on board over the 4-year study period. A higher number of seafarers with fever, cough, sore throat, and shortness of breath were assisted during the COVID-19 pandemic than before the coronavirus outbreak. Medical requests for fever increased significantly during the COVID-19 pandemic compared to the same period from 2017 to 2019. CONCLUSIONS: The requests for medical advice for fever, sore throat, and shortness of breath were significantly more common during the coronavirus epidemic. Close follow-up, regular health education on preventing coronavirus transmission, personal protective equipment, adequate environmental hygiene, and applying other standard precautions could help minimise the risk factors for the spread of COVID-19.

Clinical characteristics of the coronavirus disease 2019 (COVID-19) outbreak on a cruise ship.

BACKGROUND: A large COVID-19 outbreak occurred on the cruise ship Diamond Princess in February 2020. Little information has been reported about the clinical characteristics of the patients. METHODS: This single-center, retrospective, observational study was conducted in Yokohama, Japan. We included symptomatic patients who were infected on the ship and admitted to our hospital between 5 and 19 February 2020. All the cases were confirmed with SARS-CoV-2 infection by polymerase chain reaction (PCR). RESULTS: We confirmed 17 cases. The average age was 69 years; 10 patients were Asian and 7 were Caucasian. Eleven patients had one or more chronic diseases. The major symptoms were cough and fever. Chest computed tomography (CT) scans found bilateral ground-glass opacities predominantly in the peripheral area, which were similar to reports from cases in China. C-reactive protein (CRP) levels were higher in severe and critical cases than in mild to moderate cases. The moderate to severe cases reached symptomatic resolution; one of the three critical cases resulted in death due to multiple organ failure. SARS-CoV-2 was detected by PCR at an average of 7 days after symptomatic resolution. CONCLUSIONS: Cough and fever, increased blood CRP levels, and CT findings of bilateral ground-glass opacities predominantly in the peripheral lung were characteristic of the COVID-19 cases in this study. These findings were compatible with those of previous reports.

Chronology of COVID-19 Cases on the Diamond Princess Cruise Ship and Ethical Considerations: A Report From Japan.

The Diamond Princess cruise ship has been anchored at the Yokohama port in Japan since February 3, 2020. A total of 691 cases of the coronavirus disease 2019 (COVID-19) infection had been confirmed as of February 23. The government initially assumed that the infection was not spreading aboard and therefore indicated that any persons who either tested negative for the virus or were asymptomatic should immediately disembark. However, on February 5, the government set a 14-day health observation period because of the severity of the infection. Passengers confirmed to be free from infection began disembarking on Day 15 (February 19) of the quarantine. The effectiveness and validity of infection control, justification for the timing of inspections, and even the nature of COVID-19 itself now are all in question. The ethical considerations related to cruise ship infection control include the reasonable justification for isolation, the psychological fragility and quality of life of the isolated passengers and crew members, the procedural justice inherent in a forced quarantine, and the optimization of control measures.The international coordination framework and the global ramifications of such outbreaks should be reevaluated by the international community. Denying a ship's entry based on local politics is incompatible with global justice. Events such as these require an international response and global regulations that seek to reduce disparities.

Estimation of the reproductive number of novel coronavirus (COVID-19) and the probable outbreak size on the Diamond Princess cruise ship: A data-driven analysis.

BACKGROUNDS: Up to February 16, 2020, 355 cases have been confirmed as having COVID-19 infection on the Diamond Princess cruise ship. It is of crucial importance to estimate the reproductive number (R0) of the novel virus in the early stage of outbreak and make a prediction of daily new cases on the ship. METHOD: We fitted the reported serial interval (mean and standard deviation) with a gamma distribution and applied "earlyR" package in R to estimate the R0 in the early stage of COVID-19 outbreak. We applied "projections" package in R to simulate the plausible cumulative epidemic trajectories and future daily incidence by fitting the data of existing daily incidence, a serial interval distribution, and the estimated R0 into a model based on the assumption that daily incidence obeys approximately Poisson distribution determined by daily infectiousness. RESULTS: The Maximum-Likelihood (ML) value of R0 was 2.28 for COVID-19 outbreak at the early stage on the ship. The median with 95% confidence interval (CI) of R0 values was 2.28 (2.06-2.52) estimated by the bootstrap resampling method. The probable number of new cases for the next ten days would gradually increase, and the estimated cumulative cases would reach 1514 (1384-1656) at the tenth day in the future. However, if R0 value was reduced by 25% and 50%, the estimated total number of cumulative cases would be reduced to 1081 (981-1177) and 758 (697-817), respectively. CONCLUSION: The median with 95% CI of R0 of COVID-19 was about 2.28 (2.06-2.52) during the early stage experienced on the Diamond Princess cruise ship. The future daily incidence and probable outbreak size is largely dependent on the change of R0. Unless strict infection management and control are taken, our findings indicate the potential of COVID-19 to cause greater outbreak on the ship.