First of all, thank you very much for your interest and your relevant remarks about our article “COVID-19 on board a cruise ship: medical management” [1].
We do agree with you when you write: “Because the study only comprises one ship and its crew members, the sample size is quite limited. This small sample size may not be typical of the larger population or provide an in-depth insight of COVID-19 transmission patterns on cruise ships in general.” [2].
We can specify that we reported on medical management on a single ship and tried to determine whether there are benefits or not of the presence of a medical doctor on board and what can be experienced. Our findings are available for this particular situation and this kind of ship. It is important to state these limitations clearly.
Nevertheless, we think that at that time, during the evolution of the pandemic, there were no medical management strategies than non-specific preventive measures and treatments. For us, isolation in onboard cabins is quite similar to isolation in in-land rooms. And it was the principal way to limit the spread of the pathogen on board.
Moreover we reported the cases on board the Jacques Cartier in order to aggregate information on COVID-19 pandemic in the maritime sector. If the experience of one ship’s contamination is not sufficient to draw general conclusions, we can refer to other publications onboard different ships. And we finally found some similarities that allowed us to conclude in the effectiveness of the measures taken onboard.
You write: “False positive and false negative can still occur and it is necessary to interpret the results with concerns on possibility of the false result. The quality control of all laboratory investigation on ship might be difficult but it is needed.” [2].
We know that and we need a quality control for medical devices on board ships. And it was done in this case. We can also mention that even some false positive or false negative tests can occur, the onboard laboratory is: (i) practical; (ii) transportable, and (iii) appropriate to give quick answers to biological questions regarding many infectious diseases in patients on board, such as COVID-19.
In our cases, passengers and crew were tested by reverse transcription-polymerase chain reaction (RT-PCR) on the Biosynex© machine on board (VITA PCR Credo Diagnostics©) and all positive samples were re-tested. They were also re-run to verify the positive RT-PCR test results at the Starmetropolis© Dubai inland laboratory.
Conflict of interest: None declared