VSP Gastrointestinal Illness Surveillance

Learn how we track cases of gastrointestinal illness on cruise ships.

The Vessel Sanitation Program (VSP) maintains an electronic surveillance system that tracks cases of gastrointestinal illnesses on cruise ships under our jurisdiction. We use this system to help the cruise ship industry prevent and reduce gastrointestinal illnesses on cruise ships. We monitor the system to observe illness patterns.

African american woman suffering from stomach ache, holding belly on edge of bed.

How does the surveillance system work?

Cruise ships are required to log and report to VSP the number of passengers and crew members that say they have symptoms of gastrointestinal illness. Ships are also required to keep a list of all passengers and crew members that have received or been issued antidiarrheal medication.

Passengers and crew tell ship medical staff they are sick. If it is a reportable case of gastrointestinal illness, it is entered in the log.

Medical staff send a report to VSP that shows the total number of gastrointestinal illness cases for both passengers and crew.

What is a reportable case of gastrointestinal illness?

VSP defines gastrointestinal illness as three or more loose stools within a 24-hour time period or what is more than normal for that person, OR vomiting along with one of the following symptoms:

  • diarrhea, or
  • muscle ache, or
  • headache, or
  • abdominal cramp, or
  • fever.

When do ships report gastrointestinal illnesses to VSP?

Cruise ship medical staff are required to send gastrointestinal illness case reports to VSP at these specific times:

  • Twenty-four to thirty-six hours before arriving to a U.S. port from a foreign port. This initial report is required even when there are no cases of gastrointestinal illness.
  • If the number of ill passengers or crew changes after the initial report, but before the ship is 4 hours from arrival.
  • When 2% or more of the passengers or crew are ill. This report must be sent any time the vessel is in the United States or within 15 days of arrival at a U.S. port.
  • When 3% or more of the passengers or crew are ill. This report must be sent any time the vessel is in the United States or within 15 days of arrival at a U.S. port.
  • When unusual illness symptoms are reported to the ship’s medical staff. Unusual gastrointestinal symptoms include relatively high incidences of illnesses in successive cruises, unusual severity of illnesses or complications, high numbers of persons reporting illnesses over a brief period, and suspicion of an uncommon causative agent.

What does VSP do with surveillance reports?

We monitor and evaluate reports of gastrointestinal illness aboard ships to

  • Determine if a high number of people are sick.
  • Find out if unusual cases occur.
  • Provide support to the cruise line and cruise ship crew as they respond to an increase in cases.
  • Analyze illness patterns over time.

VSP provides support and technical assistance when

  • the number of ill passengers or crew members reaches 2% or more of the total number of passengers or crew members or
  • an unusual gastrointestinal illness pattern or characteristic is found.

Learn what VSP does in an outbreak.

How can I protect myself from gastrointestinal illness?

  • Use proper handwashing techniques throughout your voyage, but especially after using the bathroom and before eating.
  • Avoid any food or water that you think may be contaminated.
  • Avoid raw or undercooked shellfish.
  • Avoid unnecessary direct hand contact with surfaces likely to be contaminated and items a lot of people touch such as elevator buttons or public toilet room door handles.
  • Avoid unnecessary close contact with ill persons.
  • See our tips for healthy cruising.

What are common types of gastrointestinal illnesses?