Norovirus Outbreak on Cruise Ships
It’s a month before the end of the term, stress levels are rising as deadlines draw near and we count down the days before finals start. A holiday cruise seems like a perfect way to unwind and relax during your break from school or work. This was what passengers of Star Princess thought on September 19, 2015 when they boarded their 2-week long cruise to the Hawaiian Islands. Little did they know that they were about to suffer the effects of a Norovirus outbreak. On October 4th 2015, Star Princess docked in Vancouver with a total of 61 passengers who were sickened by Norovirus and displayed symptoms of acute gastroenteritis such as abdominal pain, nausea, vomiting and diarrhea. The Virus was spread through contaminated food, water and personal contact. Earlier this year, the same cruise ship experienced another Norovirus outbreak that affected a total of 135 passengers.
The cruise ship reportedly stopped at several ports where sick passengers were taken to the hospital for further treatment. Several passengers even took a flight back from Hawaii instead of continuing the journey on the cruise. In order to prevent the further spread of the virus, several measures were implemented on the cruise ship:
- Disinfection of hand railings, door handles and elevator buttons
- Hand sanitizers were placed on several locations on the ship
- Infected passengers were isolated from the rest of the passengers
A single food source has not yet been identified for the cause of this outbreak. However, the Food and Drug Administration states that the most common sources of Norovirus include water supply on cruise ships and raw oysters, fruits and vegetables. Once the virus has infected someone, it can be easily transmitted through close contact or cross contamination. A big issue with eating contaminated food on cruise ships is that the sewage and waste produced on cruise ships is dumped 12 miles from the shore. This results in contamination of shellfish that filter-feed around the area where waste was disposed. These contaminated shellfish are then harvested and consumed by people on shore, leading to more infections or outbreaks.
Norovirus outbreaks seem to be a recurring phenomenon on cruise ships with a total of 9 outbreaks recorded in this year alone. But why is Norovirus so notorious for causing outbreaks on cruise ships? Firstly, outbreaks on cruise ships are generally reported more quickly than outbreaks on land. Cruise ships also provide an ideal condition for the spread of Norovirus as it is an enclosed environment that increases the amount of person-to-person contact within the shared living space. The common source of food and drinks also facilitates the spread of Norovirus infection. Lastly, about a third of the passengers on cruise ships are elderly people who are more susceptible to Norovirus infections, which results in a greater incidence of infection.
Due to the high occurrence of this issue on cruise ships, Centers for Disease Control (CDC) has created a surveillance and reporting system to prevent and reduce the risk of spreading gastrointestinal illnesses. CDC’s Vessel Sanitation Program monitors the magnitude and distribution of cases reported, helps to implement sanitation procedures, makes recommendations for control of the pathogen and conducts investigations to determine the causative agent. If the illness rate on board the cruise is 3% or more, an investigation is performed through 3 main steps:
1) Epidemiological investigation: Measures the size of the outbreak through questionnaires, medical records and cruise ship layout.
2) Laboratory investigation: Specimens collected from infected passengers to confirm the pathogen responsible.
3) Environmental investigation: Uses information from the epidemiological investigation and further investigations to determine the source of infection.
After learning about the occurrence of Norovirus outbreaks on cruise ships, would you still consider going on a cruise? Can you think of any other ways that this issue can be prevented?
Sources:
Bert, F., Scaioli, G., Gualano, M. R., Passi, S., Specchia, M. L., Cadeddu, C.. . Siliquini, R. (2014). Norovirus outbreaks on commercial cruise ships: A systematic review and new targets for the public health agenda. Food and Environmental Virology, 6(2), 67-74.
Centers for Disease Control and Prevention. (2015). Outbreak updates for international cruise ships. Retrieved from http://www.cdc.gov/nceh/vsp/surv/gilist.htm#2015
Centers for Disease Control and Prevention. (2015). Outbreak Investigation Overview. Retrieved from http://www.cdc.gov/nceh/vsp/surv/investigationoverview.htm
Canadian Broadcasting Corporation News. (2015). Norovirus hits Star Princess, delays massive cruise ship in Vancouver. Retrieved from http://www.cbc.ca/news/canada/british-columbia/star-princess-cruise-norovirus-hawaii-vancouver-b-c-outbeak-1.3255632
International Business Times. (2015). Cruise Ship Norovirus Outbreak 2015: Dozens of Star Princess Passengers Sickened By Stomach Bug. Retrieved from http://www.ibtimes.com/cruise-ship-norovirus-outbreak-2015-dozens-star-princess-passengers-sickened-stomach-2127270
MichelleLui, 
teewong, 
Carissa Li, and 4 others are discussing.
csontani 11:20 pm on November 6, 2015 Permalink |
it’s funny cause I was actually on board another Princess cruise last August around British Isle and that ship had a Norovirus as well before my sail. I think for that case it was because of the spread from 1 infected person that boarded on the ship. I agree that there are numerous outbreaks that occur in cruise ships because they’re pretty much “isolated” in one place. Cruise ships should definitely be more strict in checking the passengers’ conditions before they board the ship. From what I see so far, they only have questionnaires that they hand out to the passengers, asking if they’ve been sick for the past couple of days/weeks, and I personally think it’s not effective cause people can just easily lie about it. So they should definitely think of a better way to monitor passengers health conditions before sailing.
cvalencia 4:17 pm on November 7, 2015 Permalink |
It is challenging to be on a cruise and find out that there is currently an outbreak going on… I can’t imagine having that constant worry in your mind that you or your family members might be the next ones to get ill. It just ruins the whole point of going on a cruise and having a peaceful vacation alone or with your loved ones. It’s also hard since there are little to no other options for other foods once you’re on the ship, but the ones that they serve on the buffet and cafes. I also think that it is devastating not only for the passengers but also for the cruise company, since they will now have a bad reputation because of these outbreaks. It’s great to know though that the CDC are providing guidelines to prevent future outbreaks.
Silvia Low 1:47 pm on November 12, 2015 Permalink |
This is so saddening to hear. I love cruise ships but I have heard of the many onboard outbreaks they often have. My understanding of how they reduce the risk of infection/contamination is by having their employees serve all the food at the buffet instead of passengers self serving. Anyway, I donot think any one cruise company should have their reputation or brand tarnished because of this because it could also be the passengers’ fault for bringing infectious illnesses onboard and the cruise companies do specifically ask all passengers if they’re sick or experiencing any symptoms prior to boarding.
shinnie 2:54 am on November 18, 2015 Permalink |
I believe that the newly implimented measures to prevent the spread of the virus on cruise ships will not be as effective as perceived. In fact, it may worsen the spread of the virus if the employees are led to think that hand sanitizers alone are enough to eliminate the pathogens. If sanitizers with insufficient ethanol content are used (60-65% of normal hand sanitizers is NOT enough), norovirus will not be eliminated. Studies show that hand sanitizers are useless against norovirus because the virus is non-enveloped and protected by a capsid. Statistics from the U.S. Centers for Disease Control and Prevention in winter of 2006-2007 show that “facilities in which staff used alcohol-based sanitizers were six times more likely to have an outbreak of norovirus compared to those in which staff cleaned their hands using soap and water.” The best methods to minimize norovirus outbreaks on cruise ships include minimizing food contact or food contact surfaces with bare hands and using extremy hot water and bleach to clean dishes and stainless steel surfaces. Proper hand washing should be strongly enforced on cruise ships as studies show that they are more effective in eliminating norovirus than sanitizers due to physical foce. For me personally, I will probably go on a cruise expecting to catch some kind of stomach flu.
Carissa Li 3:32 am on December 13, 2015 Permalink |
I was on a cruise ship this past summer too and I can relate how quickly an infection can be spread inside an enclosed environment. In my case, one of my family members caught a flu before the trip start and within 2 days, 5 other family members got infected with the flu. How quickly that was! With norovirus, I think the rate can get even faster since everyone is consuming the same food which is only one of the several routes Norovirus can take to infect people. I know that one of the surveillance cruise ships take is once they identified anyone who’s at risk, they will send them to the hospital at the next port they arrive. It is very important to make sure we all get sanitized before walking into any restaurants on the ship so as to prevent any bacteria contaminating the food as well as prevent ourself getting infected by others.
teewong 7:04 pm on December 14, 2015 Permalink |
I agree with this post entirely about the fact that cruise ships are more susceptible to these types of outbreaks as people are confined in a close proximity area. I was planning on booking a cruise trip this coming summer and this really made me second think my decision. I think if I were to follow through with my decision in booking a cruise trip, I would bring my own cutleries and personal towels to minimize any cross contaminations with other passengers.
I was also wondering, in the post it didn’t mention what the cruise company did to compensate the passengers that fell ill from this infection, did they compensate these passengers at all?
MichelleLui 10:13 pm on December 18, 2015 Permalink |
Cruise ship can certainly provide an environment that facilitate the spread of foodborne illnesses. Good personal hygiene and sanitation program should be followed by cruise ship workers. Passengers should be prepared and take preventative measures such as immunization and follow good hygiene practices (e.g. wash hands often).