Home > Travel-Associated Legionnaires' Disease
Travel-Associated Legionnaires' Disease
For Health Departments: Common Q&As
Patient Questions: If the Patient Fact Sheet does not answer your specific question(s), please contact CDC-INFO at cdcinfo@cdc.gov or (800) CDC-INFO.
Why should travel-associated Legionnaires' disease be a priority?
About 20-25% of all Legionnaires' disease reported to CDC is travel-associated.
Legionnaires' disease is important to diagnose and to report because its identification implies the presence of an environmental source to which other susceptible individuals are likely to be exposed. Clusters of Legionnaires' disease associated with travel to hotels or aboard cruise ships are rarely detected by individual clinicians or health departments; travelers typically disperse from the source of infection before developing symptoms. Therefore, a travel history should be actively sought from patients with community-acquired pneumonia and Legionella testing should be performed for those who have traveled in the 2 weeks before onset of symptoms.
Because of the multi state nature of travel in the U. S., national-level surveillance is necessary to detect outbreaks of travel-associated Legionnaires' disease. CDC relies upon state and local health departments to conduct this surveillance. Surveillance through the National Notifiable Diseases Surveillance System (NNDSS) is still important for monitoring national trends; all cases should be reported through NNDSS.
CSTE adopted a position statement relevant to travel-associated Legionnaires' disease
[PDF 101KB, 4 pages] in 2005.
How should I report a travel-associated case of Legionnaires' disease?
Because of the public health importance of timely reporting, inform CDC of travel-associated cases by emailing travellegionella@cdc.gov.
For a single case residing in your jurisdiction, inform the other relevant state health departments. Click here for a list of state health department web sites.
Notify the hotel (sample letter
PDF 65KB, 2 pages)
What diagnostic tests can confirm Legionnaires' disease?
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Urine Antigen |
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Serology |
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DFA |
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How do I start interviews?
Interview the patient or the patient's proxy (spouse, adult offspring, etc.) about the patient's movements in the 2-10 days before onset. Be sure to take a good travel history including dates of travel and address of lodging including room number if known. Use this sample hypothesis-generating questionnaire
[PDF 424KB, 6 pages] which can be incorporated into your state electronic notifiable disease surveillance system.
Where can I get information on environmental sampling?
Environmental testing guidelines
PDF 3.7MB, 15 pages
Environmental sampling/testing should only be conducted after careful consideration of the epidemiologic evidence linking a case(s) to a particular location. If environmental sampling/testing is conducted, it should be done in accordance with published guidelines. For more information, see
- Sampling protocol
PDF 901KB, 5 pages
- Procedures for collecting and processing
- Potential sampling sites
What do I tell hotel operators, hot tub maintenance staff, and others about de-contamination?
There are many options available for remediation of water systems contaminated with Legionella. Considerations include type of water system (e.g., cooling tower, potable water, hot tub), demonstrated effectiveness, cost, and ease of application. Consultation with an experienced Legionella contractor is recommended, as general guidelines are often difficult to apply to complex and varied water systems. For additional information about remediation, see: American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. ASHRAE Guideline 12-2000: Minimizing the risk of legionellosis associated with building water systems. 2000. (Also available from Baltimore Air Coil Company.)
What can CDC do to assist us as we begin to investigate a potential cluster of Legionnaires' disease?
- Epidemiologic assistance
CDC staff, including Epidemiologic Intelligence Service officers (EIS), is available to assist you as you define terms of your outbreak, as well as to help centralize communication among state health departments in a travel-associated case or outbreak. We can also assist with: case definitions, travel-associated reporting, and reporting in general. Download a case report form.PDF 439KB, 2 pages
Inform CDC about travel-associated cases by emailing travellegionella@cdc.gov. We are trying to improve the efficiency of travel-associated surveillance at CDC and need your help. See the home page for more details. Please continue official reporting mechanisms through NNDSS and through submission of case report formsPDF 439KB, 2 pages.
Public inquiries: Please contact CDC INFO at 1-800-CDC-INFO, (800-232-4636), TTY: (888) 232-6348 24 hours/every day, cdcinfo@cdc.gov - Laboratory testing
CDC does not accept laboratory specimens of any type without clearance through the Respiratory Diseases Branch prior to submission. This includes urine antigen testing, specimens for culture, or other submissions for either initial or confirmatory testing.
CDC Laboratory testing is only done under special circumstances, e.g., an outbreak investigation that CDC is involved with, or if CDC has granted prior permission for submission of specimens. Routine laboratory submissions are not accepted by the CDC laboratories.
- Sample outbreak questionnaires and other tools
Samples of questionnaires used in institutional outbreaks, tracking travel-associated cases, or other situations are available on our website. They are free for you to download and use as tools or 'starter points' as you begin your investigation. (See the home page for examples.)
What should I tell providers in my state or area?
Let them know to be alert for new cases. Encourage them to obtain lab testing, the preferred methods being cultures of respiratory secretions or tissue, and urine antigen testing.
Who has authority over cruise ships?
Email CDC Vessel Sanitation Program
Where can I get Legionella statistics?
The MMWR weekly report or the Annual Surveillance Summary.