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There has been ongoing media coverage of the cases of coronavirus, and the quarantine efforts aboard the Diamond Princess cruise ship.
Dr Nathalie MacDermott, NIHR Academic Clinical Lecturer, King’s College London, said:
“The COVID19 situation on board the Diamond Princess is unusual. While cruise ships have previously been associated with outbreaks of norovirus infections, once affected individuals are isolated in their cabins until symptoms resolve the outbreak is usually contained. The failure of the quarantine on board the Diamond Princess requires a full investigation to determine whether quarantine measures were appropriately implemented or whether some form of environmental contamination has occurred through contact with surfaces, the re-circulation of air between cabins or the mixing of waste materials from different cabins. While a thorough investigation may provide new insights into understanding viral transmission of SARS-COV2, conclusions cannot be drawn on this until such an investigation is completed and clear breaches in quarantine measures excluded.
“Given the circumstances on board the Diamond Princess, those passengers leaving the boat should be managed in a similar manner to those individuals departing a highly affected city or region, as such a further 14 day self isolation or quarantine period would be advisable even in the absence of symptoms.”
Dr Bharat Pankhania, Senior Clinical Lecturer, University of Exeter, said:
“It should be possible to bring back all British nationals whether they have tested negative or positive for the virus if they are well enough, though we don’t know what the decision will be. Special measures would need to be taken for the infected and the ill passengers, but it could technically be done.
“It’s very interesting that there have been so many cases onboard, and of much more concern that these cases appear to have arisen after the ‘lock down’ on the ship.
“Initially the plans for containment on the ship were to quarantine the passengers, in the hope that the infection would die away. Instead, more cases have arisen and the pattern for the new cases arising after the ‘lock down’ seems to suggest there has been another route of transmission of infection to the passengers in their cabins.
“During the 2002 SARS outbreak, cases were generated via a hotel’s ventilation shaft. If this is also the case on the ship, it indicates that the ship was not a suitable place for holding a large number of cases with a centralised air conditioning system. The normal route is droplet spread. My supposition is based upon the large number of cases on the cruise liner when we were told all holiday makers were confined to their cabins, all the time. How did they manage to make so many cases, over a period of time considering interactions with fellow passengers was supposedly not happening?
“In the same light, this raises issues about looking after people who are infected with the virus in a facility where the same ventilation and air conditioning systems may be in place, whether a hospital or other facility. If transmission is possible via these systems, which we can’t yet be sure about, then much thought must be given to where infectious people are cared for in the quarantine phase or as cases.
“If the UK passengers are repatriated to the UK, it would be sensible to offer them stricter quarantine conditions. They appear to have been in an environment where transmission of infection has occurred and over several days, thus their risk of having been exposed to the virus is greater and their chances of being infected also greater.”
Dr Simon Clarke, Associate Professor in Cellular Microbiology, University of Reading, said:
“While cruise ships are not typically known for being breeding grounds for infectious disease, having a large number of people in relatively close confines, is a recipe for transmission. There have previously been problems on such ships with spread of viruses that cause diarrhoea and vomiting. Unfortunately, the more elderly demographic found on a typical liner are more likely to be susceptible to anything which might present a serious health challenge.
“It might have been better to remove the passengers from the Diamond Princess and house them on land nearby during the 14-day quarantine period, but finding suitable accommodation for around 3,700 people for a two week quarantine period, plus enough medical staff to look after them, would have presented a significant obstacle to this. Moreover, if those passengers had spread COVID19 coronavirus to the local population in Japan, that would have caused serious logistical and political problems for those local health authorities.
“If someone has coronavirus, but is not sick, it’s a political call as to whether the risk should be taken to repatriate them. If they are ill and there are suitable medical facilities wherever they happen to be, it might be best to leave them overseas until they are fit enough to travel, but there are established ways of transporting people who are ill and depending on how unwell they are, the logistics, the risk and of course the cost will vary.”
Prof John Oxford, Professor of Virology, Queen Mary University of London, said:
“Cruise ships are very prone to outbreaks of common cold and the vomiting virus, Norovirus. Invariably the ships are overcrowded and with so many passengers hygiene levels can slip. I suspect also that the passengers have not been properly quarantined since they have gone through a virus incubation time and infections are still appearing. There must be a great temptation to interact with other passengers exercising on deck etc. and we know paper masks are not fully effective. Quarantine on a ship is not as strict as proper quarantine. In fact it might be impossible to properly quarantine people on a ship. I am sure that passengers will need to be quarantined properly when they return home. And that they will be monitored.”
Prof Paul Hunter, Professor in Medicine, UEA, said:
“Since the cases of COVID19 were identified on the Diamond Princess about two weeks ago the ship was put into quarantine. It is well known that certain infections such as influenza and Norovirus can spread rapidly on board cruise ships. Cruise ships take passengers and crew from all over the world, often passengers are relatively elderly, they spend most of their time on board indoors mixing with others, and then they leave to go home or continue their holidays.
“The primary reason for the quarantine was to stop potentially infectious people then spreading infection further around the world as they continued their holidays or returned home. In this regard it would appear that the quarantine has so far been successful.
“However, with the high number of cases reported in the past few days it would appear that measures to prevent spread amongst passengers and crew after quarantine was imposed were ineffective. How and when these new cases acquired their infections is not currently clear so the reasons how and indeed when this transmission occurred in not yet known. The most likely route is direct person to person transmission when people are close to an infected person, but with currently publicly available information it is not possible to rule out other issues at this stage. I am sure the Japanese will be investigate this to identify the likely transmission pathways and make sure lessons are learned.
“Given that the safety from infection of remaining passengers and crew cannot be guaranteed, several countries are repatriating their nationals. Whilst such efforts are understandable and indeed desirable for the currently quarantined passengers, such repatriation is not free from risks. Considerable care needs to be made to ensure that the passengers do not transmit infection between themselves or to cabin crew during the flight home and once back on home soil they do not act as a focus for the spread of the disease into their home countries – any returning passengers may be put in quarantine on their return.”
All our previous output on this subject can be seen at this weblink:
http://www.sciencemediacentre.org/tag/covid-19
The SMC also produced a Factsheet on COVID-19 which is available here:
https://www.sciencemediacentre.org/smc-novel-coronavirus-factsheet/
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