The first official norovirus outbreak on a cruise ship this year involved the Norwegian Cruise Line (NCL) Norwegian Star.
The outbreak occurred during a cruise from January 5-19, 2014. The virus sickened 130 of 2318 cruise passenger (5.61%) and 12 of 1039 crew members (1.15%). You can read the CDC report here.
The CDC concluded that the virus in question which sickened the 142 or so people was norovirus. This was the “causative factor” in CDC parlance. The CDC can usually figure out the “causative factor” and most of the time norovirus is the culprit. But I have never seen a CDC report in the last 10 or 15 years where the CDC figured out how the norovirus came aboard the cruise ship.
The cruise lines always blame the passengers. Sometimes the blame is direct with a cruise line public relations representative pointing the finger at their guests. Sometimes it is more subtle with no blame assessment but in the form of “passengers-need-to-wash-their-hands” type of admonishment.
Determining the cause of a norovirus outbreak is a scientific process to be made by epidemiologists and doctors, not cruise line PR people.
The CDC is severely limited by the few inspectors and epidemiologists who are assigned to the cruise ships. The cruise lines are also eager to re-load their cruise ships and begin another cruise as soon as possible. Our federal government and the cruise lines work together to keep the cruise industry moving. No one wants to inconvenience the next round of passengers and hold a ship in port. Unfortunately, no one is advocating a more comprehensive (and slower) methodical analysis of data.
My suggestion is that any time there is an outbreak, the CDC should automatically conduct a sanitation inspection as soon as the ship returns to port pursuant to its vessel sanitation program (VSP). The inspectors should determine whether the cruise ship’s food or water supplies are contaminated. Medical literature indicates that many outbreaks are due to noro-laden food or water. Particular attention should be focused on the crew members’ medical records, particularly the logs indicating whether food handlers (cooks and waiters) have reported to the ship infirmary with acute gastrointestinal symptoms of cramping, diarrhea and nausea.
Yes, it will take greater resources from the CDC to accomplish this but it is worth it. The “enhanced cleaning” that takes place after an outbreak is “hit or miss.” No one figures out what caused the outbreak. The ship is just pressing everyone to work overtime and spray and wipe everything in sight.
There was no CDC sanitation inspection on January 19th when the Norwegian Star returned to port. I would have liked to see the food handler’s medical logs for the preceding two weeks in order to determine whether there were complaints of nausea, diarrhea, cramps, fever and headaches. How did the cruise line handle the illnesses? Did they log all of the complaints and quarantine the sick crew members? Did they interview the crew members’ cabin mates to determine whether they were ill too?
The Norwegian Star underwent a CDC sanitation inspection on February 16th. The results were disgusting. Many crew members worked while suffering from acute gastrointestinal illnesses, threatening the health of passengers, and then appeared in the ship infirmary after working. The cruise line failed to properly document and log many of the sicknesses and report them to the CDC. For the January 19th to February 2nd 2014 cruise, the number of sick passengers reached over 2% but the cruise ship did not notify the CDC. Many of the cabin mates of the sick crew members were not interviewed by the ship’s medical staff, as required by the CDC protocols.
The following violation was typical:
“Violation: On 28 January, the medical notes indicated a food worker had an illness onset at 0600 with four episodes of diarrhea, abdominal cramps, and a headache, but the AGE surveillance log indicated these symptoms started on 28 January at 1315. On the same day at 1315, this person had their last AGE symptom. There was no documentation indicating how long this person was isolated. This individual had four roommates, but there was no documentation the 48 hour interviews were conducted for three of the four roommates.”
The CDC flunked the ship with a score of 82. You can read the CDC report here. In addition to the problems with the sick crew members, parts of the galleys and restaurants were filthy.
Does the CDC employ epidemiologists to study the results of vessel sanitation reports to look for trends to explain why gastrointestinal outbreaks occur? Correlating the medical records of sick food handlers and their cabin mates with outbreaks may be a good idea. A scientific analysis of medical records and logs of crew members with GI problems would certainly be a better use of time than having to listen to the cruise line always blame the passengers for not not washing their hands.
Photo Credit: Top: Wikipedia / Pjotr Mahhonin; bottom: Centers for Disease Control & Prevention