Infectious diseases at sea can pose severe problems, not only for the crewmember or passenger affected, but also for others aboard, for ship operations, and for port health clearance.
Point of care (POC) testing has the potential to improve the speed and reliability of diagnosis and hence for treatment and outbreak control. The study by Bouricha and colleagues in this issue provides evidence of the practicality of using such tests on board a ship as well as noting the need for modifications to POC equipment to make it sufficiently robust for maritime use.
The authors couple the use of POC testing with a simple syndromic (signs and symptoms based) system to help decide if testing is indicated. They indicate, from evidence in other settings, the potential benefits of such testing, but the small number of tests performed in this study means that the benefits of adoption of such test methods at sea cannot readily be evaluated. More studies are clearly needed to provide answers on the cost effectiveness of such testing before it can be recommended for general use.
The management of medical emergencies at sea is underpinned by requirements in international conventions that are adopted into the national law of maritime states and these provide for basic minimum standards. The elements of this standard are provision of medications and equipment, a ship hospital, an international or national medical guide, training for deck officers to a level that should enable them to use the guide, provision of medications and equipment, and availability of a shore-based radiomedical service to manage illness and injury until the ship arrives in the next port or until evacuation of the casualty is arranged. Ships with over 100 persons on board, operating distant-from-shore—now almost all exclusive cruise liners—are also required to have a doctor and additional medical facilities on board.
Because of the multiple elements in the medical emergency system, all of which are the subject of regulation, practices are slow to change and tend to be modified only rarely rather than reflecting recent developments in diagnosis, treatment, and prevention. For this reason, progressive ship operators act well in advance of regulatory requirements to introduce additional provisions to help manage medical emergencies. It is here that POC tests for infections are most likely to be adopted, as they have already been used for a number of diagnostic applications in the cruise industry, where the justification is strongest because of the larger crews and especially the larger numbers of passengers who join the ship without prior medical selection and so have a higher risk of ill-health.
There would be advantages if similar equipment could be used for POC testing in both infectious and noninfectious conditions, as this would provide more economic justification for the installation of the equipment required. The overall costs, both capital and for replacement of consumables, either because they have been used or because they have become outdated, will need to be considered and it is likely that the business case for installation will be strongest when there are large numbers aboard.
An approach to medical management based on presenting symptoms and signs (syndromic) rather than one based on reaching a diagnosis has many advantages in the maritime setting and it is here that POC testing can best form a logical part of the decision-taking process. The key question here has to be: does such testing improve the outcome of the condition in the individual or the management of its consequences when compared to other means of reaching a decision on treatment and infection controls? This must remain an open question until more extensive evaluations of use at sea, or from related distant-from-shore settings, becomes available. Those with an interest in the development and marketing of POC tests will need to build many more effective partnerships of the type that made this study possible if this goal is to be achieved.
If use of such tests is to become the norm, a skeptical and economically tough-minded international shipping industry will need to be convinced of the benefits, so that such testing is adopted into conventions and associated recommendations and these lead to adaptations of training, medical equipment requirements, and telemedical advice arrangements worldwide. This can be seen as one measure helping to fulfill the goal of the ILO Maritime Labour Convention 2006 that:
The requirements for on-board health protection and medical care set out in this code include standards for measures aimed at providing seafarers with health protection and medical care as near as possible to that which is generally available to workers ashore.
However, proof of the benefits from the use of POC tests will be needed to use this goal as a justification for their general adoption.