Opinion & Comment:
HYGIENE ON CRUISE SHIPS: CDC'S VESSEL SANITATION
PROGRAM
By Thomas E. O'Toole, M.P.H., Deputy Chief
Special Programs Group
National Center for Environmental Health
(Published October
1994)
Two recent episodes of disease (Legionnaires' disease and shigellosis) aboard cruise ships have focused attention on the Vessel Sanitation Program ("VSP"), a small public health service provided by the Centers for Disease Control and Prevention("CDC"). In 1975, because of several major disease outbreaks on cruise vessels, CDC established the VSP as a cooperative activity with the cruise ship industry. VSP staff assist the cruise ship industry to develop and set up sanitation programs that will minimize the risk of passengers and crew contracting gastrointestinal diseases.
Every vessel that has a foreign itinerary and carries 13 or more passengers is subject to twice-yearly inspections and, when necessary, re-inspection. The vessel owner pays a fee, based on tonnage, for all inspections. The cost of two inspections is 1.2 cents per passenger or crew member per day for an extra large ship and 1.5 cents for a medium-size ship.
Although cooperation with the VSP inspection program is voluntary for carriers, CDC is authorized by § 361(a) of the Public Health Service Act to take any measures necessary to prevent the introduction, transmission, or spread of communicable diseases in the United States from a foreign country (42 United States Code, § 264(a)). Regulations designed to carry out this duty authorize CDC to conduct regular sanitary inspections of carriers traveling to a U.S. port from a foreign area (42 Code of Federal Regulations (CFR), § 71.41). This inspection is to determine whether ships have vermin, contaminated food or water, or other unsanitary conditions that may contribute to the introduction, transmission, or spread of communicable diseases.
VSP inspectors calculate whether a ship is in compliance with the program's recommendations by totaling individual scores for 42 preset criteria. Full information on inspection criteria can be obtained by writing to the VSP office (the address is at the end of this article). A score of 86 points out of 100 is the threshold for determining a ship's compliance. In general, the lower the score, the lower the level of sanitation; however, a low score does not necessarily imply an imminent risk for gastrointestinal disease. Each ship is required to document a plan for corrective action following each inspection. Inspectors will recommend that a ship not sail if they detect an imminent health hazard aboard ship (e.g., inadequate facilities for maintaining safe fond temperatures or a contaminated drinking water system). At any time, the Director of CDC may determine that failure to implement corrective actions presents a threat of introduction of communicable diseases into the United States and may take additional action through the CDC Division of Quarantine, including detention of the ship in port.
The scores for each ship are published every two weeks in the Summary of Sanitation Inspections of International Cruise Ships, commonly referred to as the green sheet. This sheet is distributed to more than 4,500 travel-related services around the world and is a way to communicate a ship's compliance with VSP recommendations to both the cruise ship industry and the consumer. The green sheet is also available by writing to the VSP office.
VSP has three categories for ships in the program: Regularly Sail From US Ports (ships that use US ports for more than 6 months during the year); Seasonally Sail From US Ports (ships that use US ports for three to six months during the year); and Occasionally Sail From U. S. Ports (ships that use US ports for less than three months during the year). The percentage of inspection scores that are 86% or higher Las steadily increased from 51% in 1988 to 80% in 1993 (see VSP Chart 1). These percentages are for all ships inspected - not just for one category. Ships that score below 86% are re-inspected within 30 to 60 days, when possible. All ships that regularly sail from US ports have, at least once, achieved a score of 86% or higher. Occasionally the score of a ship may fall below 86 % to the low 80s or high 70s. Some ships, however, get scores in the low 60s, and recently one ship scored 42. On ships that score in the low 60s or below, little is being done correctly.
VSP also monitors reports of diarrheal illness on each vessel at the end of each cruise and will conduct an investigation if those reports show that more than 3 % of the passengers were ill. In the 1970s and early 1980s, 12 to 15 outbreaks of diarrheal illness occurred each year; however, the number of outbreaks decreased to I to 3 in the 1990s. Another way to lock at this is that the rate of an onboard outbreak of diarrhea illness has declined from 8.1 outbreaks per 10 million passenger-days when the program was first implemented to approximately 2.1 outbreaks per 10 million passenger-days in recent years (see VSP Chart 2). This dramatic improvement is the direct result of the cruise ship industry's commitment to following VSP's recommendations, VSP's consultation services and classes on sanitation for cruise ship personnel, and VSP's highly skilled staff.
Cruise ship companies frequently ask VSP staff to help them improve their onboard sanitation efforts, and VSP is happy to oblige. Other services include providing information about emerging diseases and the risks those diseases create for the cruise ship industry. Periodically VSP sends cruise ship companies an advisory letter about various public health concerns and recent changes in public health practices and interpretations.
Mr. O'Toole, M.P.H., is Deputy Chief of the Special Programs Group of the National Center for Environmental Health in Atlanta, Georgia. One of his primary areas of responsibility is ensuring public health safety on cruise ships. Interested parties can obtain additional information regarding the Vessel Sanitation Program by writing to Vessel Sanitation Program, National Center for Environmental Health, 101S North America Way, Room 107, Miami, FL 33132.
