Cleanest cruise lines revealed after CDC surprise sanitation inspections

Cruise ships were graded on a 100-point scale. To pass inspection, ships must score 86 or above. 

The Viking Ocean Cruises II Ltd., Viking Expedition Operations and Crystal Cruises were tied as the cleanest cruise lines, according to the study. Each cruise line scored a 99 out of 100.

"The federal government's Vessel Sanitation Program (VSP), established in 1975 to work with the cruise industry to protect travelers' health, is critical for the health and safety of passengers, staff and the locations that cruise ships visit," Gavin Macgregor-Skinner, an infection prevention expert and epidemiologist, told Fox News Digital.

Oceania Cruises, P&O Cruises, Japan Grace, Virgin Voyages, Norwegian Cruise Lines, Celebrity Cruises and Royal Caribbean International completed the top 10 cleanest cruise line list.

All the ships in the top 10 scored higher than 97.12.

Viking, Virgin and Norwegian were the corporations that ranked the highest, with sanitation scores of 98.75, 97.67 and 97.39, respectively, according to the study.

Royal Caribbean and Carnival had average sanitation scores of 96.74 and 94.82, respectively.

But the CDC implements strict cleaning protocols for all vessels.

"Cruise ships are shared environments where thousands of people touch the same surfaces every day," Brian Sansoni, senior vice president of communications at the American Cleaning Institute in Washington, D.C., told Fox News Digital.

"Without strong cleaning and hygiene practices, germs can spread quickly, increasing the risk of illness among passengers and crew," he continued.

Surprisingly, the study found no link between viruses and the lack of cleanliness.

Macgregor-Skinner said cruise lines are the only part of the travel sector that routinely report illnesses to the federal government.

"It is very important not to confuse the wider availability of cruise health data with a higher incidence rate on cruise ships compared to settings like restaurants, hotels and planes," Macgregor-Skinner said.

Overall, the cruise industry is actually cleaner than other travel sectors, he said.

According to the study, here are the top 10 cleanest cruise lines. 

Viking Ocean Cruises

Viking Expedition Cruises

Crystal Cruises

Oceania Cruises

P&O Cruises

Japan Grace

Virgin Voyages

Norwegian Cruise Line

Celebrity Cruises

Royal Caribbean International