A new study has revealed the cleanest cruise ships in the world, with some outlets reporting the results of surprise sanitation inspections by the CDC. The study appears to have ranked cruise lines based on their cleanliness, with some lines being identified as the cleanest and others as having poor sanitation. However, the specific rankings and details of the study's findings are not consistent across all reports, with some outlets also mentioning unrelated rankings of river cruise lines and overall best cruise lines.