Vectorborne Diseases

Vectorborne Diseases

Cruise ship port visits may include countries where vectorborne diseases such as malaria, dengue, yellow fever, Japanese encephalitis, and Zika are endemic. New diseases might surface in unexpected locations. For example, chikungunya was reported in late 2013 for the first time in the Caribbean (with subsequent spread throughout the Caribbean and numerous North, Central, and South American countries and territories). Zika virus was first reported in Brazil in 2015 and subsequently spread across the Caribbean and Latin America. See Chapter 3 for additional information on specific vectorborne diseases.

Passengers should follow recommendations for avoiding mosquito bites and vectorborne infections:

  • Use an effective insect repellent (see Chapter 2, Protection against Mosquitoes, Ticks, & Other Arthropods).
  • Treat clothing and gear with permethrin or purchase permethrin-treated items.
  • While indoors, remain in well-screened or air-conditioned areas.
  • When outdoors, wear long-sleeved shirts, long pants, boots, and hats.
  • Obtain yellow fever vaccination if recommended or required.
  • Take antimalarial chemoprophylaxis if needed (see Chapter 3, Yellow Fever & Malaria Information, by Country).

Other Health Concerns

Stresses of cruise ship travel include varying weather and environmental conditions, as well as unaccustomed changes in diet and physical activity. Foreign travel may increase the likelihood of risk-taking behaviors such as alcohol misuse, drug use, and unsafe sex. In spite of modern stabilizer systems, seasickness is a common complaint (affecting up to one-fourth of travelers) (see Chapter 2, Motion Sickness). Cruise lines may not allow women to board after the 24th week of pregnancy, and pregnant women should contact the cruise line for specific policies and recommendations before booking (for additional information, see Chapter 8, Pregnant Travelers).

Preventive Measures for Cruise Ship Travelers

Cruise ship travelers often have complex itineraries due to multiple, short port visits. Although most of these port visits do not include overnight stays off the cruise ship, some trips have options for travelers to venture off the ship for ≥1 night. Therefore, cruise ship travelers may be uncertain about potential exposures and which antimicrobial prophylaxis, immunizations, and preventive measures should be considered. Box 6-1 summarizes recommendations for cruise travelers and clinicians advising cruise travelers in pretravel preparation and healthy behaviors during travel. Travelers with special medical needs, such as wheelchairs, oxygen tanks, or dialysis, should inform their cruise line before traveling. Travelers with health conditions should carry a written summary of essential health information (electrocardiogram, chest radiograph, if abnormal, blood type, chronic conditions, allergies, treating physician contact information, and medication list) that would facilitate their care during a medical emergency. In addition, all prospective cruise travelers should verify coverage with their health insurance carriers and, if not included, consider purchasing additional insurance to cover medical evacuation and health services in foreign countries (see Chapter 2, Travel Insurance, Travel Health Insurance, & Medical Evacuation Insurance).

Box 6-1. Cruise travel health precautions

Advice for Clinicians Giving Pretravel Cruise Consultations

Risk Assessment and Risk Communication

  • Discuss itinerary, including season, duration of travel, and activities at port stops.
  • Review the traveler’s medical and immunization history, allergies, and special health needs.
  • Discuss relevant travel-specific health hazards and risk reduction.
  • Provide the traveler with documentation of his or her medical history, immunizations, and medications.

Immunization and Risk Management

  • Provide immunizations that are routinely recommended (age-specific), required (yellow fever), and recommended based on risk.
  • Discuss food and water precautions and insect-bite prevention.
  • Older travelers, especially those with a history of heart disease, should carry a baseline electrocardiogram to facilitate onboard or overseas medical care.

Medications Based on Risk and Need

  • Consider malaria chemoprophylaxis if itinerary includes port stops in malaria-endemic areas.
  • Consider motion sickness medications for self-treatment (see Chapter 2, Motion Sickness).

Precautions for Cruise Ship Travelers


  • Evaluate the type and length of the planned cruise in the context of personal health requirements.
  • Consult medical and dental providers before cruise travel.
  • Notify cruise line of special needs (such as wheelchair access, dialysis, oxygen tank).
  • Consider additional insurance for overseas health care and medical evacuation.
  • Carry prescription medications in their original containers, with a copy of the prescription and accompanying physician’s letter.
  • Bring insect repellent and sunscreen and consider treating clothes and gear with permethrin.
  • Defer travel while acutely ill.
  • Consult for travel health notices.
  • Check for gastrointestinal outbreaks.

During Travel

  • Wash hands frequently with soap and water. If soap and water are not available, use an alcohol-based sanitizer that contains ≥60% alcohol.
  • Follow safe food and water precautions when eating off the ship at ports of call.
  • Use measures to prevent insect bites during port visits, especially in malaria- or dengue-endemic areas or areas where outbreaks of vectorborne diseases, such as chikungunya and Zika, are occurring.
  • Use sun protection.
  • Maintain good fluid intake, but avoid excessive alcohol consumption.
  • Avoid contact with ill people.
  • If sexually active, practice safe sex.
  • Report illness to ship’s infirmary and follow medical recommendations.

Reporting Illness after Travel

Travelers who become ill after returning home should inform their health care providers of where they have traveled. Clinicians should report suspected communicable diseases in recently returned cruise ship travelers to public health authorities:

  • Report GI illnesses related to cruise ship travel to the CDC VSP by calling 800-CDC-INFO (800-232-4636) or by visiting and clicking on “Contact CDC-INFO” in the bottom right hand corner.
  • Inform CDC of any travel-associated Legionnaires’ disease cases by sending an e-mail to
  • Report communicable diseases to their local public health authority. Health departments should notify the CDC quarantine station of jurisdiction ( for communicable diseases of public health concern during travel.


  1. Cramer EH, Slaten DD, Guerreiro A, Robbins D, Ganzon A. Management and control of varicella on cruise ships: a collaborative approach to promoting public health. J Travel Med. 2012 Jul;19(4):226–32.  [PMID:22776383]
  2. Freeland AL, Vaughan GHJ, Banerjee SN. Acute gastroenteritis on cruise ships—United States, 2008–2014. MMWR Morb Mortal Wkly Rep. 2016 Jan 15;65(1):1–5.  [PMID:26766396]
  3. Guyard C, Low DE. Legionella infections and travel associated legionellosis. Travel Med Infect Dis. 2011 Jul;9(4):176–86.  [PMID:21995862]
  4. 4. Hill CD. Cruise ship travel. In: Keystone JS, Freedman DO, Kozarsky PE, Connor BA, Nothdurft HD, editors. Travel Medicine. 3rd ed. Philadelphia: Saunders Elsevier; 2013. pp. 349–55.
  5. Lanini S, Capobianchi MR, Puro V, Filia A, Del Manso M, Karki T, et al. Measles outbreak on a cruise ship in the western Mediterranean, February 2014, preliminary report. Euro Surveill. 2014 Mar 13;19(10):2–6.
  6. Millman AJ, Kornylo Duong K, Lafond K, Green NM, Lippold SA, Jhung MA. Influenza outbreaks among passengers and crew on two cruise ships: a recent account of preparedness and response to an ever-present challenge. J Travel Med. 2015 Sep-Oct;22(5):306–11.  [PMID:26031322]
  7. Mouchtouri VA, Rudge JW. Legionnaires’ disease in hotels and passenger ships: a systematic review of evidence, sources, and contributing factors. J Travel Med. 2015 Sep-Oct;22(5):325–37.  [PMID:26220258]
  8. Neri A, Fazio C, Ciammaruconi A, Anselmo A, Fortunato A, Palozzi A, et al. Draft genome sequence of C:P1.5-1,10-8:F3-6:ST-11 meningococcal clinical isolate associated with a cluster on a cruise ship. Genome Announc. 2014 Dec 4;2(6).  [PMID:24744341]
  9. Peake DE, Gray CL, Ludwig MR, Hill CD. Descriptive epidemiology of injury and illness among cruise ship passengers. Ann Emerg Med. 1999 Jan;33(1):67–72.  [PMID:9867889]
  10. Tomaszewski R, Nahorski WL. Interpopulation study of medical attendance aboard a cruise ship. Int Marit Health. 2008;59(1-4):61–8.  [PMID:19227739]