I think that cholera is one of those diseases like typhoid where some people can be carriers and transmit the disease without actually coming down with the disease.
Cholera is definitely spread by contaminated water and other contacts with fecal material.
I read that with what the cruise ships are charging to house evacuees and FEMA workers that it would be cheaper for the government to send these cruise ship tenants on a cruise.
At least on a cruise there would be a debarking date.