[Peter Libra]

You pose a very cogent question here regarding the how and why.

I think I stumbled on the answer elsewhere. It seemed that the CDC themselves e-mailed the authority on board the ship. They wrote that although a person had worked in the Dallas laboratory and was a passenger, do not worry. Absolutely no chance of their being infected. Carry on and enjoy your cruise etc.

Oh boy!

[Cvengr]

If the CDC assurances weren't enough to scare the reasonable, they're now terrified after John Kerry's reassurances to Mexico of the ship's safe status.

Maybe the cruise line theme can be "Day of the Dead!"