Larry, it is only a snap shot in time with the CDC score. Many ships scored 100 at the last inspection. Check the link below:
http://wwwn.cdc.gov/InspectionQueryTool/InspectionWith100Score.aspx

I am guessing that someone throw some marketing dollars at some place and someone writes a positive article. Notice that only a specific cruise line is singkled out when clearly there are a lot more ships scoringg the 100.

There had been situations (several) that there were novovirus outbreak and the ship that had the outbreak scored 100 at their most current inspection.

I think that by and large, all ships are clean. They depend on it.

Larry,

The cruise critic article mentioned that Carnival Splendor achieved "an unprecedented sixth perfect score since the vessel's debut in 2008".

I just take a peek at a few ships that I had been on and here is what I have found.

The Diamond Princess scored six perfect score in a row between July 2007 to September 2010 (which is more impressive than the Splendor getting their 6th perfect score), and after one lowly score of 97 (compared to 98 and 99 of the Spelndor), returned with 2 perfect scores in a row, giving it an amazing eighth perfect score since 2007, (which is 2 more than the "unprecedented" sixth perfect scores of the Splendor)

I would say that there's a bit of a hype and a bit of promo and I guess we just can't believe everything that we see on the internet.

http://wwwn.cdc.gov/InspectionQueryTool/InspectionResults.aspx

The Diamond Princess CDC scores are as fellow:
5/24/2012 100
9/6/2011 100
5/25/2011 97
9/14/2010 100
5/25/2010 100
9/15/2009 100
5/20/2009 100
5/27/2008 100
12/3/2007 100
7/14/2007 98
2/3/2007 95