Last month, the P&O Oceana flunked a sanitation inspection with a score of 82 out of 100, according to the CDC report, which was released April 1. The CDC chided the cruise line for kitchens with soiled grout, insect remains and “potentially” hazardous food. A passing score is 85. The inspectors also shut down the Oceana’s swimming pool after a spot check found it had chlorine levels that were too low, the report said..

Only four other cruise ships have failed a CDC inspection since 2008.

In February, another P&O vessel, the Oriana received one of the lowest scores of any P&O ship in six years. CDC inspectors wrote up a laundry list of problems. Among them: Utensils were stored unprotected in front of the temporary sneeze shield; and three live cockroaches, one adult and two nymphs, were observed in the two undercounter hot boxes underneath the grills in the galley. The Oriana was awarded a score of 90, which is a “pass.”

P&O cruises, which is a unit of Carnival, said it was “extremely disappointed” in the result of the inspections. “We immediately rectified the areas identified as needing attention,” Michele Andjel, a Carnival spokeswoman, told Fortune.

The cruise line hasn’t yet submitted a corrective action report, a formal filing that outlines how it plans to fix the problems.

Among the highlights of the reports:

• A Chef de Partie, or line cook, experienced onset of gastrointestinal illnesses symptoms in January on the Oriana. The crew member worked from 7 a.m. to 11 am, took lunch at the crew mess, then returned to work from 1 p.m. to 5 p.m, according to the report. The crewmember reported his symptoms to the medical center at 6 p.m. Among the paper records of this case was a written reprimand for not reporting these symptoms immediately. Cruise lines are quick to blame passengers for gastrointestinal illnesses such as the Norovirus, but critics have long contended that unsanitary employees share some of the blame.
• The Oceana experienced a problem with its cheese, with the temperature in one refrigerator as high as 50°F. The recommended temperature range for storing cheese is between 35°F and 45°F. One tray containing smoked cheddar and Lester cheese measured 46°F and 44°F, and had to be discarded. The other cheeses in the unit were within temperature, and were transferred to another unit. Spoiled cheese can lead to food poisoning, which is not an uncommon complaint. Cruise lines tend to dismiss these grievances, but these results suggest the accounts may have some merit.
• One of the starboard pantries on the Oceana had an insect infestation. Inspectors counted nine fruit flies on the seam to the deckhead above the preparation counter behind the beverage station. They recommended the cruise lines more effectively control the presence of insects, rodents, and other pests to minimize their presence in the food storage, preparation, and service areas and warewashing and utensil storage areas aboard a vessel.

A spokeswoman for the Cruise Lines International Association, an industry trade group, said it is “keenly focused on keeping ships clean and safe.” It also fully cooperates with the CDC on all inspections.

“The process starts even before a ship leaves port, including screening of passengers for any illnesses they may have contracted on land,” said Elinore Boeke. “Passengers are also reminded to wash hands regularly, just as people should do on land, and hand sanitizers are located throughout a ship.”

The health report comes at a time when some cruise lines have had Norovirus outbreaks. Just last month, 150 were stricken on the Diamond Princess in Australia, and 135 passengers fell ill on the the Norwegian Gem in New York. March is considered the peak of high season for infectious diseases, but the cruise industry and its supporters have generally argued that unsanitary passengers — not employees — are the cause of the malaise.

It also raises questions about the industry’s squeaky-clean image, and indeed, that there may be more unreported cases that were either ignored or dismissed by the sickened passengers or the cruise lines themselves.