These are the 8 nastiest cruise ships

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Japan Cruise Line's Pacific Venus ship.

• Of the more than 200 active cruise ships the Centers for Disease Control and Prevention have inspected, the vast majority have received passing grades, which means they scored at least an 86 on the agency's 100-point sanitation score.
• But a handful earned failing grades for a variety of reasons, including improperly-stored food and the presence of flies in food and beverage areas.
• Japan Cruise Line's Pacific Venus ship received the lowest score, with 76 points out of 100.
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Most cruise ships are pretty clean, according to the Centers for Disease Control and Prevention (CDC), which inspect ships to make sure they maintain proper sanitation.

Of the more than 200 active cruise ships the CDC have inspected, the vast majority have received passing grades, which means they scored at least an 86 on a 100-point sanitation score. But a handful have earned failing grades for a variety of reasons, including improperly-stored food and the presence of flies in food and beverage areas.

These are the eight cruise ships that currently operate in the US market and received a failing grade during their most recent CDC inspection, ranked in descending order of the inspection score.

Read more: Royal Caribbean just opened a $250 million private island for its cruise passengers that has a 135-foot-tall waterslide - here's what it looks like