Talking Point: COVID-19: specific maritime medical challenges

October 06, 2020
Coronavirus 4

Originally published: 10 September 2020

Talking Point is a series of thought pieces written by experts in the maritime industry, offering insights into different topics affecting seafarers. This month, we hear from Dr Sue Stannard, Consultant at the Norwegian Centre of Maritime and Diving Medicine, Department of Occupational Medicine, Haukeland University Hospital in Bergen, Norway. Dr Stannard gives an overview of the current challenges during the COVID-19 pandemic and the status of medical guidance available for seafarers and shipowners.

The maritime industry is responsible for the transport of about 90% of the world’s trade1. Throughout the current pandemic, the industry has striven to maintain supply chains and the delivery of essential cargoes, including food and medical supplies, whilst ensuring the continued health and welfare of the 1.6 million seafarers serving on board ship. It has faced many challenges and these have been met by an unprecedented level of international, cross industry collaboration. All of the United Nations (UN) Agencies, the International Chamber of Shipping (ICS), the International Transport Workers’ Federation (ITF), the International Maritime Health Association (IMHA), the International Seafarers’ Welfare and Assistance Network (ISWAN) and many more organisations and governments, at an international and national level, have worked tirelessly in an attempt to manage these issues.

Challenges facing the Maritime Industry

The key medical and health challenges that the industry has faced in recent months include but are not limited to:

  • The management of an active case on board
  • The need to establish physical distancing and other measures to reduce the spread of the disease on a ship
  • Quarantine and Testing of seafarers
  • Access to Pre-Employment Medical Examination
  • Interaction with shore staff in ports
  • Crew changes
  • Access to medical, dental and welfare services in port
  • Reduced possibilities for shore leave
  • Contract extension
  • Increase in mental health issues in seafarers on board

Many of these issues were recognised early in the pandemic and addressed in publications from the International Maritime Organization (IMO), the International Labour Organization (ILO), the World Health Organization (WHO) and many others as early as February. The IMO issued Circular Letter 4204/12 on February 19th, identifying the international instruments in place that may be relevant to the management of a pandemic. It clearly stated the responsibility of all nations to adhere to these and to the Maritime Labour Convention 20063. The challenges, the regulations and the international response are summarised in an article published in International Maritime Health in June4.

From a medical perspective, the most challenging areas remain the management of cases on board and in port, the role of quarantine and testing and the access to medical care in ports.

What, when, how many?

The WHO recognised COVID-19 as a pandemic on March 11th 2020 and at the time of writing over 27 million cases have been reported, with over 900,000 deaths5 and the numbers continue to increase. The illness spreads by direct or indirect contact with droplets from an infected person and in order to slow the spread of the disease, and reduce the pressure on health services, many countries introduced ‘lockdown’ measures. These measures remain in place in many countries, to a greater or lesser degree, and have a major impact on the maritime industry.

No figures are currently available for the actual number of cases identified amongst seafarers serving on board a ship. Outbreaks on cruise ships such as the Diamond Princess and the Zaandam were widely reported in the press and in scientific journals6. However, reports in the press or journals of cases or outbreaks on non-passenger ships including fishing vessels, are few, suggesting that the number of cases on board these ships are limited. However, we know that there are cases on board ships as far afield as Brazil, Mozambique, Antwerp and China and some of these have unfortunately led to the death of seafarers7.

Management of COVID-19 on board

If a seafarer develops signs and symptoms suggestive of possible COVID-19, he/she should report these to the medical officer on board immediately. The seafarer should be isolated in the sick bay or his/her own cabin, preferably with access to a bathroom that is not used by others, and assessed further. Isolation of a seafarer may be very challenging depending on the size and design of the ship but isolation is the single most important factor in attempting to control the spread of the disease on board. Meals should be delivered to the cabin and a full cleaning protocol instigated.

Assistance with making a diagnosis is available at COVID-19 at sea8, designed by the Norwegian Centre of Maritime and Diving Medicine to assist in identifying a potential case and providing initial, supportive care.

The early recognition and close monitoring of a case is key to its successful management and that is one advantage of the shipboard environment. The sick seafarer should be monitored in person or by telephone, two to three times a day and a record kept of his/her symptoms and vital signs. Early involvement of a Telemedical Assistance Service (TMAS) or other shore side medical support is advised. Early access to oxygen and to more advanced medical care, if required, is essential and this has proven to be a potential issue for seafarers.

It may be that an increasing number of seafarers display symptoms suggestive of COVID-19 and therefore should isolate in their cabin and not undertake their duties. On a smaller vessel and with a limited number of crew this may lead to problems in maintaining operations and even with safe manning levels. If this situation should arise a full risk assessment and management plan should be developed in communication with shore side management, medical staff within the company or from TMAS and flag state representatives. Further information on the management of suspected COVID-19 cases on board can be found in the ICS documents ‘COVID-19 - Guidance for Ship Operators for the Protection of the Health of Seafarers’9 and ‘Protocols to mitigate the risk of cases on board ships’10.

Management of close contacts on board

In a shipboard environment the sick seafarer is likely to have been in contact with many/most of the other seafarers, depending upon the size of the ship, number of people on board and of course the position of that seafarer. The WHO publication ‘Operational considerations for managing COVID-19 cases or outbreaks on board ships: interim guidance’11 published in March 2020, defines a close contact as anyone who has ‘had physical contact (face to face contact within 1 metre for more than 15 min) or were in a closed environment with a suspected or confirmed COVID-19 case’. In addition, close contacts are those who have shared a cabin and those that have provided medical care to a suspect case. The ICS guidance advises that close contacts, and therefore seafarers at high risk of transmission of the virus specifically include those that have:

  • had close contact within one metre or were in a closed environment with a suspect/confirmed COVID-19 case (for example tank work, shared watch in an engine control room, eaten a meal with);
  • participated in the same immediate travelling group without quarantine before boarding the ship;
  • been a cabin steward who cleaned the cabin of a suspect/confirmed case of COVID-19.

If the number of high-risk close contacts is relatively small, they should be asked to quarantine in their cabin as long as to do so would not endanger the safety of the ship, those on board, or the ship’s operation.

Again, on a small ship if one seafarer develops possible COVID-19 all seafarers will be close contacts and should therefore quarantine for up to 14 days. Obviously, this is impractical on such a vessel as operations would be severely impaired and the ship unable to function. In these circumstances, all seafarers should self-monitor for symptoms and report anything suggestive of COVID-19 immediately. Daily temperature screening may be appropriate, as may the wearing of a face covering and the use of shipboard social distancing as outlined in the ICS Guidance and the WHO document, ‘Promoting public health measures in response to COVID-19 on cargo ships and fishing vessels’12, produced in August.

Management of suspected cases in port

It is imperative that any seafarer requiring medical attention, whatever the possible diagnosis, must be allowed to disembark the ship to receive necessary care. This is clearly outlined in the MLC 20063 and other maritime conventions.

The ship must report all suspect cases to the relevant health authorities at the next port of call as per the International Health Regulations (2005)13. For ships on an international voyage and calling at a foreign port, the Maritime Declaration of Health must be completed. Discussions as to the management of suspect cases, testing of seafarers on board, further medical care or isolation and monitoring should ideally take place before the arrival of the ship in port so appropriate arrangements can be made.

As a minimum, all seafarers with symptoms suggestive of COVID-19, and identified close contacts, should be tested by a Polymerase Chain Reaction (PCR) test on arrival in port. Ideally, tests will be conducted for all seafarers on board. Once the test results are available, those with a positive test result should be separated from those who are negative. Either the ‘positives’ or the ‘negatives’ could remain on board the ship whilst the others are managed ashore in appropriate accommodation. Alternatively, both groups can be managed ashore in separate areas/facilities. Those with an initial negative test should be monitored closely and a repeat test taken if they develop symptoms or as per a local recommended testing schedule.

Once seafarers have completed appropriate quarantine or isolation they may be allowed to re-join the ship or be repatriated. Further information on the advised isolation of positive cases, with or without symptoms, is available from the WHO in their document ‘Criteria for releasing COVID-19 patients from isolation’14.

If a large number of seafarers on board are infected with COVID-19, a complete crew change is advised with a thorough deep clean of the ship before the new seafarers go on board.

Quarantine and Testing

The role of testing and quarantine in managing the risk of seafarers bringing COVID-19 on board when they join a ship is a matter of much discussion. Quarantine requirements and testing policies vary hugely around the world, as do the requirements of different shipping companies. Any test only provides a snapshot of the moment it was taken. It cannot predict whether a seafarer will develop COVID-19 in the coming days, particularly if they are in contact with others and/or travelling to join a ship. Whilst a positive test at any point will ensure a seafarer with the virus does not undertake onward travel or board the ship, a negative test should be interpreted with care, in discussion with medical personnel and in the context of any clinical findings.

IMHA has produced an interim document, ‘Getting Healthy Seafarers to a Ship’15, that recommends 14 days of quarantine at the point of embarkation, in combination with testing, as the ideal way to try to ensure that new joiners do not carry COVID-19 on board. This may be difficult to achieve and other strategies involving testing and shorter periods of quarantine may be considered. However, any such strategy comes with an increased risk and this must be assessed as part of a full risk management plan. The quarantine and testing of seafarers in their home country will ensure that any who test positive do not travel to a ship but it will not ensure that all seafarers are free of coronavirus at the time of embarkation.

The PCR test is the most accurate to detect the presence of the virus but it is not widely available out of a health care setting and still has up to a 30% false negative rate due to issues including but not limited to:

  • Poor technique in taking the swab
  • Taking the swab too early in the illness
  • Issues in transportation and transport media
  • Delay in transport or analysis
  • Human error in interpretation and poor equipment in the laboratory. This may be a particular issue with the level of health infrastructure is poor and the numbers of skilled personnel are limited

These tests are certainly not recommended for use on board. Rapid diagnostic tests to detect either the virus antigen or antibodies produced because of prior infection are not yet accurate enough for use outside of a research or health care setting16.

Accessing medical care in ports

During recent months there have been many reports of seafarers refused access to medical care in ports for all medical conditions, even if they are clearly not suspected COVID-19 cases. Early on in the pandemic there were cases of a broken leg, a stroke, appendicitis, chest pain possibly due to a heart attack and visual disturbances17 that were refused access to care in the nearest port. On some occasions the intervention of the IMO, the ICS and the ITF were required to ensure that the seafarer received essential medical care. Whilst local and national lockdowns may have restricted the access to medical care for everybody, if medical facilities are available in port and are open to the local population, they should also be available to seafarers. MLC 20063 states this clearly.

If a ship is considering diversion for urgent medical care a risk assessment should be completed to decide the nearest, appropriate port for that individual case and access to care must be a factor in that assessment. If a ship experiences difficulty in accessing care ashore they should consider the use of TMAS, a ship’s agent or other port intermediaries to assist.

On the other hand, there are reports of the shipping company, Captain, or the seafarer themselves refusing shore leave to access medical care in some ports where the risk of COVID-19 is perceived to be high. Medical advice can be given by telephone or video conference but the risk of leaving port with a sick seafarer on board a ship should not be underestimated.


There are many more challenges that can and should be discussed, not least of which is the number of seafarers still unable to leave ships because of the difficulties in changing crew. This and other issues have a detrimental effect on crew wellbeing and their mental health in particular. Many have striven to raise awareness of this18, 19.

The medical challenges presented to the shipping industry are significant and much has been done and is still being done to address them, and to manage the risk to seafarers, ship operations, local shore personnel and others. Knowledge about the virus increases all the time and advice on the management of cases, quarantine and testing will change. As time moves on, alternative treatment options will be developed and their efficacy confirmed and hopefully a vaccine will be developed that will protect the most vulnerable in society and assist in reducing transmission. In the meantime, what is vitally important is that the entire maritime industry – seafarers, shipping companies, flag states, port states, P&I companies and the international organisations continue to work together to ensure maritime trade is maintained and our seafarers and ships remain healthy.

Sue gained her medical degree from the University of Birmingham in 1995 and has a clinical background in Acute Medicine, Anaesthetics/ITU and Paediatrics.

She worked as a Ship’s Doctor for P&O Princess and was later Medical Director at Carnival (UK) Cruise Lines with responsibility for the on board and shore side medical departments, all medical staff and the Public Health Department. Sue was also Medical Director (Assistance) at International SOS in London overseeing all medical assistance cases. These included evacuation and repatriation flights, monitoring of medical cases overseas and providing medical advice to leisure and business travellers, expats and companies.

Sue is currently a Consultant at the Norwegian Centre of Maritime and Diving Medicine in Bergen where her role includes the training of Doctors in assessment of the fitness of seafarers and offshore workers, international liaison with other maritime authorities within Northern Europe and research. She is also the Editor of the third edition of the Textbook of Maritime Health. During the current pandemic, Sue has contributed to many published documents related to the management of COVID-19 in the maritime setting and participated as a panellist in webinars hosted by the World Health Organization, the International Chamber of Shipping and the International Labour Organization.

1 Accessed August 27th 2020
2 Accessed August 27th 2020.
3 Accessed August 27th 2020.
4 Stannard S. Covid-19 in the maritime setting: the challenges, regulations and the international response: International Maritime Health 2020. Vol 72:2, pages 85 – 90.
5 Accessed September 9th 2020.
6 Dahl E. Coronavirus (Covid-19) outbreak on the cruise ship Diamond Princess. International Maritime Health 2020. Vol 71: Number1; p5 – 9.
7 Accessed August 27th 2020.
8 Accessed August 27th 2020.
9 Accessed October 6th 2020.
10 Accessed August 27th 2020.
11 Accessed August 27th 2020.
12 Accessed September 4th 2020.
13;jsessionid=A0E3F22529F1DCD356D207BE1424E7C6?sequence=1. Accessed August 27th 2020.
14 Accessed August 27th 2020.
15 Accessed August 27th 2020.
16 Accessed August 27th 2020.
17 Accessed September 4th 2020.
18 Accessed August 27th 2020.
19 Accessed August 27th 2020.

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