The popular cruise blog written by Gene Sloan for the USA Today newspaper published an article yesterday entitled "Outbreaks of Illness on Cruise Ships at Multiyear Low."
CruiseLog cites statistics from the U.S. Centers for Disease Control ("CDC") of 11 outbreaks of illnesses so far in 2011, down from 14 in 2010 and 15 in 2009. It concludes that this reflects a "downward trend that began several years ago as the industry increased prevention efforts."
But looking at the data at the CDC website, you can see that the "trend" is actually flat, with 14 to 15 outbreaks reported to the CDC for each the past 3 years (2008, 2009 and 2010). This year will probably end up with the same number of reported incidents.
There has been an additional outbreak reported to the CDC just since the CruiseLog article was published yesterday. HAL's Ryndam cruise ship has reported that more than 5% of its passengers reported to the ship's infirmary complaining of vomiting and diarrhea. You can read about this latest outbreak here. The cruise ship is returning to Tampa tomorrow.
Unfortunately, there seems to be an outbreak or two over the Christmas and New Year sailing somewhere each year, so we should reasonably expect there to be the usual number (14 to 15) this year as in past years.
My real criticism of the CruiseLog article is not whether the number is actually 15 versus 11. It is that the article really doesn't explain that the cruise ship outbreaks reported to the CDC are probably less than 50% of the actual number of incidents which occur around the world each year. Remember that cruise lines do not report sickness outbreaks to the CDC if the cruise does not call on a U.S. port. This is significant because many cruise lines re-positioned a greater number of their cruise ships to Europe and Asia in recent years compared to five years ago
Although it is difficult to track the incidents outside of the U.S., we have reported on a number of incidents this year.
For example, in September, norovirus broke out on Celebrity's Eclipse sailing out of Southampton, England. Royal Caribbean's cruise ships sailing out of this U.K. port remained on heightened alert for months. You will find no mention of this is in the official CDC database. The cruise lines certainly will never voluntarily disclose this.
In November, we reported on one death and 80 sick passengers on HAL's Veendam which experienced a sickness outbreak as the cruise reached in Rio de Janeiro.
The other issue that the CruiseLog does not explain is the cruise lines report disease outbreaks only when 3% of passengers are afflicted based on the number of ill passengers who appear in the ship infirmary. This is significantly less than the true number of those afflicted with viral illnesses. Many sick passengers know that they will be quarantined in their cabins or they simply do not want to wait in the long lines outside of the ship infirmary.
The Clinical Infectious Disease Journal reported earlier this year that 40% of passengers with a viral infection did not report being sick to the ship medical staff. If these passengers were included in the sickness count, then the number of CDC reportable cases would surely increase.
CruiseLog also points to Carnival as not reporting a single outbreak this year. Does that mean that Carnival has a vaccine against the cruise ship bug? Hardly. Consider the following comments by cruise passengers on the CruiseJunkie website about the Carnival Conquest last week:
"From a passenger: There was an outbreak of something vomiting and diarrhea starting on Tuesday of the cruise (4-11 Dec). My husband got sick on Thursday morning and was asked to stay in cabin on isolation. On Friday I came down with vomiting and diarrhea. We were told there were lots of people sick.
Another passenger writes: On our final day at sea suddenly all the crew was wearing gloves and none of the passengers were allowed to get their own plate or food at the buffet. Everything had to be served by the staff and they were constantly wiping down everything and making announcements about hygiene. We asked if something was going on and we were told no however by that night 3 of the seven people in our party were very sick and once we walked in on an employee in the bathroom vomiting very badly. A casino employee told us that night many of the crew and passengers were very sick.
When we were getting off the boat Sunday we saw stacks and stacks of mattresses in plastic they were loading on the ship. We still have people from our group sick and I wish we had been told something. We received no information and since I was traveling with two children and my seventy year old father I continue to be concerned."
Families intending to cruise and worried about norovirus should read news sources like CruiseLog with a grain of salt. There is no empirical evidence that norovirus and other cruise ship sicknesses are on the decline.
Regarding cruises not calling on a U.S. port, the best sources of information are anecdotal, like cruise community forums and websites not beholden to the cruise lines like Professor Ross Klein's CruiseJunkie.