Travel medicine is devoted to the health of travelers who visit foreign countries. It is an interdisciplinary specialty concerned not only with prevention of infectious diseases during travel but also with the personal safety of travelers and the avoidance of environmental risks. The field has evolved as a distinct discipline over the last 2 decades. It is represented by an international society - the International Society of Travel Medicine (ISTM) - and by an active clinical group within the American Society of Tropical Medicine and Hygiene (ASTMH). Those who practice in the field come from a wide range of specialty training experiences; however, it is members of the infectious disease community who have frequently taken the lead in providing the evidence base for practice. Accompanying the growth of travel medicine has been a parallel effort in defining a body of knowledge and standards for its practice. These guidelines set forth the minimum standards for knowledge, experience, and practice in travel medicine and review the major content areas in the field. Travel medicine standards are increasingly based on evidence and are moving away from reliance on the opinion of experts. Where possible, recommendations in this document have been graded using the Infectious Diseases Society of America - United States Public Health Service grading system (table 1) . As a young discipline, however, expert opinion and experience still dominate many of the topic areas, highlighting the need for continued investigation in the field. Setting. Most travel medicine care should be performed in a specialized travel clinic by persons who have training in the field, particularly for travelers who have complex itineraries or special health needs (C-III). Primary care physicians and nonspecialists should be able to advise travelers who are in good health and visiting low-risk destinations with standard planned activities. Knowledge base. The knowledge base for the travel medicine provider includes epidemiology, transmission, and prevention of travel-associated infectious diseases; a complete understanding of vaccine indications and procedures; prevention and management of noninfectious travel-associated health risks; and recognition of major syndromes in returned travelers (e.g., fever, diarrhea, and rash) (A-III) (table 2). All providers should access Web-, text-, and journal-based resources. The US Centers for Disease Control and Prevention (CDC) provides authoritative advice on travel health (http://www.cdc.gov/ travel). Competency in travel medicine. Appropriate knowledge and aptitude for practicing travel medicine may be demonstrated by achieving a certificate of knowledge in the field (table 2). Maintaining competency includes ongoing education and performing pretravel consultations on a frequent and regular basis (B-III). Pretravel risk assessment. The key element of the pretravel visit is a health risk assessment of the trip (A-II) (table 3). This balances the health of the traveler (the traveler's age, underlying health conditions, medications, and immunization history) with the details of the planned trip (the season of travel, itinerary, duration, and planned activities). Spectrum of travel medicine advice. Topics of health education and advice that should be covered for all travelers include vaccine-preventable illness, avoidance of insects, malaria chemoprophylaxis (for itineraries that include a malaria risk), prevention and self-treatment of traveler's diarrhea, responsible personal behavior, sexually transmitted infections and safety, travel medical insurance, and access to medical care during travel (A-II) (table 3). Other topics should be covered as indicated by the risk assessment. Consistent and clear advice that is provided in both verbal and written form will help to increase traveler compliance with preventive measures (A-II). The interaction between traveler and health care provider should be collaborative and affords the opportunity to enhance preventive health knowledge. Records and procedures. (1) Permanent records should be maintained for the pretravel visit, including records of traveler demographic data and health history, travel health risk assessment, and immunizations, recommendations, and prescriptions given (A-III) (table 4). (2) Standard procedures for immunization should be followed, including informed consent, vaccine storage, administration, record-keeping, and reporting of adverse events (A-III). Immunization. (I) The pretravel visit should be used to update vaccinations that are routinely recommended according to US schedules and based on the traveler's age and underlying health status (A-I) (table 5). These vaccinations include tetanus, pertussis, diphtheria, Haemophilus influenzae type b, measles, mumps, rubella, varicella, Streptococcus pneumoniae, and influenza vaccinations. Vaccination against hepatitis A and B, poliomyelitis, and Neisseria meningitidis may be recommended for travel, as well as for routine health care. (2) Vaccination against yellow fever is usually indicated for travelers to countries in the zone of endemicity for yellow fever (areas in Africa and South America where conditions are conducive to yellow fever transmission) (A-III). In addition, under International Health Regulations (IHRs), some countries that lie within or outside of the zone of endemicity may require yellow fever vaccination as a condition for entry. Recent recognition of serious adverse events associated with yellow fever vaccination requires that a careful risk-benefit assessment be performed before administration of the vaccine. (3) Hepatitis A vaccination should be considered for all travelers (A-III). Booster doses following the primary 2-dose series are not currently recommended (A-II). (4) Vaccination against Japanese encephalitis, rabies, tick-borne encephalitis, and typhoid fever should be administered on the basis of a risk assessment (A-III). Quadrivalent (A/C/ Y/W-135) meningococcal vaccine should be administered to travelers at risk. It is required by Saudi Arabia for religious pilgrims to Mecca for the Hajj or Umrah. Traveler's diarrhea. Traveler's diarrhea is the most common disease among travelers. Management of traveler's diarrhea includes education and advice about prevention, food and liquid hygiene (A-III), and provision for prompt self-treatment in the event of illness (A-I) (table 6). The elements of self-treatment include hydration; treatment with loperamide for control of symptoms, if necessary (when there is no temperature >38.5°C or gross blood in the stool); and a short course (single dose to 3 days of therapy) of a fluoroquinolone antibiotic (A-I). Antibiotic resistance of enteric pathogens, particularly Campylobacter species, in the destination country needs to be considered. For those travelling to these destinations, as well as for other travelers, azithromycin may be indicated (B-II). Combination treatment with loperamide and an antibiotic may be considered for travelers with moderately severe diarrhea (B-III). Antibiotic prophylaxis is not recommended for most travelers (A-III). Malaria. (I) Malaria is one of the most severe infectious diseases among travelers (tables 7 and 8). Nearly all cases in travelers are preventable. Methods for prevention and best management of malaria include awareness of risk, avoidance of mosquito bites, compliance with chemoprophylaxis, and prompt diagnosis in the event of a febrile illness either during or on return from travel (A-I). When seeking medical care after return from travel, travelers should be instructed to inform their health provider of their travel history. (2) Travelers at risk for malaria should practice the following measures to prevent mosquito bites: wearing of protective clothing to cover exposed skin, application of repellents, and sleeping in areas protected by netting (preferably impregnated with a residual insecticide, such as permethrin) and screens (A-I). Currently, repellents that contain 20%-50% N, N diethylmetatoluamide (DEET) are considered to provide sufficient protection (B-II). (3) The choice of chemoprophylaxis should be made following a careful assessment of malaria risk during the trip. In addition, whether the traveler has contraindications to a particular antimalarial should be considered. (4) The malaria risk assessment includes the itinerary, the species of malaria at the destination (and whether the most severe form of malaria, that due to Plasmodium falciparum, is present and whether it is resistant to chloroquine or other antimalarials), the season of travel, activities, duration, and access to medical care. Consultation with the latest resource information is necessary. Personal safety and environmental heath. (1) All travelers should be aware of personal safety during travel and exercise responsible behavior (A-III). Road and pedestrian safety, risk of blood-borne infections, avoidance of animal bites, awareness of the risk of assault, sexually transmitted infections, and moderation in alcohol use should be discussed. (2) Travelers should understand the effects that air, sea, and land travel, sun, altitude, and heat and cold may have on their health. To prevent deep venous thrombosis (DVT), long-haul travelers with journeys of 6-8 h and longer should avoid constrictive clothing around their waist and lower extremities, exercise their calf muscles, and maintain hydration (A-III). Travelers with increased risk factors for DVT may consider wearing below-the-knee support stockings (B-II) or receiving low molecular weight heparin (B-I). (3) Ascent to altitudes of 2500-3500 m (8200-11500 feet) is often associated with various forms of high altitude illness. Staged ascent is an effective way to decrease the risk of altitude illness. Travelers who need to ascend rapidly may take acetaxolamide for prevention (B-I). © 2006 by the Infectious Diseases Society of America. All rights reserved.