January 6, 2004
Tips to Reduce Risk of ‘Cruise Ship Virus’
CHICAGO— Before you leave for that winter cruise, experts from the Travel Medicine and Immunization Center at the Northwestern Medical Faculty Foundation would like to have a few words with you: Viral gastroenteritis. Norwalk virus. “Cruise ship virus.”
Viral gastroenteritis is an infection that causes inflammation of the stomach and small and large intestines. The symptoms include nausea, vomiting, and diarrhea.
Norwalk and Norwalk-like viruses are the most common causes of outbreaks of viral gastroenteritis on cruise ships, and are second only to the common cold in the number of people they make ill each year, according to the Centers for Disease Control and Prevention (CDC).
The CDC reported 24 outbreaks of cruise-acquired viral gastroenteritis on 17 cruise ships in 2002. About 75 percent of the outbreaks of “cruise ship virus” were caused by Norwalk-like viruses, the CDC confirmed. Through October 2003, at least 26 outbreaks of viral gastroenteritis had been reported on cruise ships.
“We must educate cruise passengers about this disease, its causes, and preventive measures to avoid catching the viruses that cause viral gastroenteritis,” said infectious disease specialist Teresa R. Zembower, MD, assistant professor of medicine and medical director of the Travel Medicine and Immunization Center.
In addition to nausea, vomiting, and watery diarrhea, symptoms of “cruise ship virus” include fever, stomachache, and headache. The symptoms usually start one to two days after viral infection and can last from one to 10 days.
Most people who become sick with viral gastroenteritis recover quickly and have no further problems. However, for the elderly, children, and those with compromised immune systems, the illness can be more severe and require medical care to treat dehydration.
Viral gastroenteritis is contagious much like colds or flu and can be spread from person to person through ingestion of contaminated food or water, through contact with contaminated surfaces, and by contaminated hands through the fecal-oral route.
Controlling the “cruise ship virus” at the first sign of a suspected outbreak is critcal, Dr. Zembower said. Control measures include frequent, rigorous hand washing with soap and water and strict attention to basic food and water sanitation measures.
Cruise ships must receive thorough and prompt disinfection using freshly prepared chlorine solutions, phenol-based compounds, and accelerated hydrogen peroxide products; ill crew members must be isolated; and passengers must be isolated for 72 hours after they have recovered from the illness.
While no specific medications or vaccinations are available for the Norwalk-like viruses that cause viral gastroenteritis, risk for dehydration and associated complications can be lessened.
Families with infants and young children should keep a supply of oral rehydration solution (for example, Pedialyte®) on hand to be administered at the first sign of diarrhea.
Antibiotics should be avoided unless specifically recommended by a physician.
The Travel Medicine and Immunization Center specializes in the prevention of travel-related and vaccine-preventable illnesses. The center’s mission is to help patients stay healthy while traveling abroad through individualized consultation with experienced travel experts. The center also provides consultations and medical referrals if illnesses arise after the traveler returns home.
For information on the Travel Medicine and Immunization Center, call 312/695-1888 or see www.nmff.org/travelmedicine .