Tugboats are now towing the disabled ship to Mobile, Alabama, but until it gets there, some passengers are having to endure conditions they call deplorable.  And that includes reports of backed-up toilets that sent raw sewage into hallways and cabins. 

Dr. Herbert Dupont directs the Center for Infectious Diseases at the UT School of Public Health. 

"And if people touch it, which they invariably have to do, and get their fingers or hands near their mouth, they're subject to developing infections of the intestional tract."

Those infections include hepatitis and dysentery, along with norovirus, which is known as the "cruise ship virus."  Dupont worries some of those passengers could find themselves seriously ill.

"If we're talking about elderly, infirm, immunocompromised, which is what a cruise ship group is like, then a bout of dysentery or diarrhea can actually be life-threatening." 

Carnival Cruise Lines officials say a medical triage unit will be on dock when the ship arrives, but Dupont says some ill passengers may not develop symptoms until a few days after they get home.