On Sunday, 3rd May, news regarding an outbreak of hantavirus aboard a cruise ship sailing near Cabo Verde woke up the world.
The outbreak occurred aboard the MV Hondius, a vessel belonging to Oceanwide Expeditions, as it was making its way from Argentina to the Canary Islands in Spain.
Experts on infectious diseases have assured the public that such occurrences are rare but even they were surprised that hantavirus was found on board a cruise ship.
According to Dr Emily Abdoler MD of the University of Michigan Medical School: “I don’t know of any other cases reported on a cruise ship before. This is not a common infection, but it’s even less common to have the human spread raised as a possibility. Six people sick on a cruise ship; I’ve never heard of that from this kind of infection.”
Rare as hantavirus may be among humans as it is more common in animals, viral outbreaks do occur aboard cruise vessels as having so many people aboard within close proximity to each other often results in textbook examples of contagion.
Handling such outbreaks takes dedication on the part of cruise staff, and preventing them from even happening in the first place is something that global cruise lines are taking seriously.
Why cruise ships are hotspots for contagion
To understand why viral outbreaks pose such a regular challenge aboard cruise ships, let’s take a cue from a recent Science Alert report and consider each vessel a type of temporary city.
As the report states: “[Each vessel] has restaurants, theatres, lifts, cabins, kitchens, water systems, and indoor gathering spaces. That is great for convenience, but it also means that once an infection gets on board, it can move through the ship in ways that are hard to stop.”
This is especially true in the case of rapidly-spreading viruses like the norovirus, and also COVID-19 which infamously spread through the passengers and crew of the Diamond Princess back in 2020.
It was, nevertheless, fortunate that medical staff aboard the vessel quickly put measures to ensure public health and safety into place to mitigate the further spread of illness.
To quote from the conclusion of the post-contagion report from the Diamond Princess:
“The cruise ship conditions clearly amplified an already highly transmissible disease. The public health measures prevented more than 2000 additional cases compared to no interventions. However, evacuating all passengers and crew early on in the outbreak would have prevented many more passengers and crew from infection.”
Also, the spread of gastrointestinal infection could be driven by poor standards in food and beverage (F&B) handling and overall sanitation, revealing another key issue that cruise lines need to address.
What needs to be done
The US Centres for Disease Control and Prevention (CDC) has a long-standing protocol in place in the event of a shipwide outbreak consisting of three key steps:
- Cruise staff are mandated to immediately notify the onboard medical team in the event that they or any passengers experience symptoms;
- US cruise ships are required to report all cases of certain illnesses; and
- The CDC’s Vessel Sanitation Programme (VSP) must commence an outbreak response even before laboratory results can confirm the presence of infectious pathogens.
Through this protocol, outbreaks get detected more quickly than on land and the impact of contagion can be brought down to a bare minimum.
But even without such protocols in place, cruise lines need to implement their own environmental safety measures which may include:
- Greater cleaning frequency, especially in high-traffic areas, using high-potency sanitisers, especially those formulated to prevent the spread of viral and / or bacterial infection;
- Heating, ventilation, and air-conditioning (HVAC) systems need to be equipped with specialised filters, as well as vents for the better circulation of fresh air throughout the vessel, thus reducing the spread of air-borne illnesses;
- Food and beverage services must be held to the highest standards of hygiene and routine inspections conducted on the regular to ensure compliance; and
- Provision of quarantine areas staffed with medical teams with ample experience in viral and bacterial infections as both a standard and preventive measure.
At the same time, passengers also need to do their part by looking to their own personal hygiene routines and becoming proactive should they or their companions show signs of being unwell.
By doing so, cruises can be made safer and trips made more enjoyable for everyone aboard.
