Norovirus outbreaks of international cruise ships

Cruise ships participating in the Vessel Sanitation Program (VSP) are required to report the total number of gastrointestinal (GI) illness cases–including zero–evaluated by the medical staff before the ship arrives at a U.S. port, when sailing from a foreign port.

A separate notification is required when the GI illness count exceeds 2% of the total number of passengers or crew onboard.

Data from CDC-led investigations is available from each year.The GI illness cases reported are totals for the entire voyage and do not represent the number of active (symptomatic) GI cases at any given port of call or at disembarkation.

Cruise ship outbreak updates are posted when they meet the following criteria:

  • Fall within the purview of VSP (see about VSP),
  • Are sailing on voyages from 3-21 days,
  • Are carrying 100 or more passengers,
  • Are cruise ships in which 3% or more of passengers or crew reported symptoms of diarrheal disease to the ships medical staff during the voyage, and
  • Are gastrointestinal illness outbreaks of public health significance.

This year the following cruises reported outbreak on their journey.

Cruise Line Cruise Ship Sailing Dates Causative Agent
Princess Cruises Crown Princess 4/5 – 4/12 Norovirus and Enterotoxigenic E. coli (ETEC)
Royal Caribbean Cruise Line Grandeur of the Seas 4/5 – 4/12 Norovirus
Royal Caribbean Cruise Line Grandeur of the Seas 3/28 – 4/5 Norovirus
Holland America Line ms Maasdam 3/2 – 3/28 Unknown
Holland America Line ms Veendam 2/8 – 2/22 Norovirus
Princess Cruises Caribbean Princess 1/25 – 2/1 Norovirus
Royal Caribbean Cruise Line Explorer of the Seas 1/21 – 1/31 Norovirus
Norwegian Cruise Line Norwegian Star 1/5 – 1/19 Norovirus

Failing at the VSP inspection

Several passenger ships fail the vessel sanitation inspection conducted by the CDC health inspectors twice a year. The scale is 100-point and every score under 85 is considered failing. Main purpose of the program is prevention and control of the introduction, transmission and spreading of gastrointestinal diseases.

  • Regent – Seven Seas Navigator
  • Un-Cruise Adventures – Safari Endeavour
  • Silversea – Silver Shadow
  • Celebrity Summit
  • Golden Princess
  • Ocean Princess
  • SeaDream II
  • Bahamas Celebration
  • FleetPro Ocean ms Nova Star.

What the CDC health inspectors usually find on board these ships is food debris, dead insects, insect droppings and records indicating crewmembers (including cooks) working while sick (gastrointestinal disorders or with acute gastroenteritis/AGE symptoms). The list of additional violations includes: cracked/corroded equipment, soiled cutting boards, food served undercooked, lack of safety instruction signs.

In contrast the “perfect 100″ vessels are Carnival Legend (Carnival Cruise Lines), (Disney Cruise Lines) and Eurodam (Holland America Line).