eMedicine Specialties > Emergency Medicine > Infectious Diseases

Travel Medicine and Vaccination

Bret A Nicks, MD, Assistant Professor, Assistant Medical Director, Department of Emergency Medicine, Wake Forest University Health Sciences
Debra Slapper, MD, Consulting Staff, Department of Emergency Medicine, St Anthony's Hospital

Updated: Feb 4, 2009

Introduction

An estimated more than 800 million travelers worldwide cross international boundaries each year.¹ However, whether associated with tourism, humanitarian efforts, globalization of industry, or migrant workers, studies suggest only a small number seek pre-travel health advice. In addition, the composition of those traveling continues to become more diverse and medically complex, creating a vastly different perspective on travel-associated medical concerns, preparations, and required medical knowledge.²

With these decreasing boundaries and increasing activities, travel medicine has become a rapidly evolving field of medicine. Classically, travel medicine focused on individuals traveling to developing countries with prevention and treatment of malaria, traveler's diarrhea, and general vaccinations as its primary goal. Travel medicine has subsequently become a dynamic multidisciplinary specialty that encompasses aspects of infectious disease, public health, tropical medicine, wilderness medicine, and appropriate immunization. Although these aspects are broad in reach, they are tightly integrated within the realm of travel medicine and require appropriate understanding prior to venturing out.

So, whether you are a humanitarian aid worker in Tanzania, an educator in Latin America, a tourist, or a businessperson for a multinational corporation, understanding the dynamics of travel and the interplay of healthcare will minimize the adverse effect of travel-related illnesses and concerns while maximizing enjoyment and success for the trip.

Travel Medicine: The Big Picture

The specialty of travel medicine is dynamic and vast in its medical knowledge requirements. Areas of expertise include vaccinations, epidemiology, region-specific travel medicine, pre-travel management, travel-related illnesses, and post-travel management.

Although the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) provide the backbone of current medical considerations, several groups have taken a paramount role in developing a structured curriculum to better identify the realm and role of travel medicine as a subspecialty of care. Two such examples are the International Society of Travel Medicine (ISTM) and the American Society of Tropical Medicine and Hygiene (ASTMH). The formation of such groups has allowed for a more open dialogue about the required body of knowledge for the practice of travel medicine and thereby improved related resources to an ever-expanding diversity of travelers.

In addition, recent establishment of collaborative sentinel surveillance networks specifically to monitor disease trends among travelers offers new supplemental options for evaluating travel health issues. These networks can inform pre-travel and post-travel patient management by providing complementary surveillance information, facilitating communication and collaboration between participating network sites, and enabling new analytical options for travel-related research. TropNetEurop and GeoSentinel represent two major networks currently available. Data obtained from studying health problems among travelers may provide significant benefits for local populations in resource-limited countries. However, given their limitations, they should be considered as complementary tools and not relied on as an exclusive basis for evaluating health risks among travelers.²

Pre-travel Medical Preparation

Annually, Americans make more than 300 million trips to other countries. An increasing number of these trips are to developing countries, and, according to the CDC, 30-60% of these travelers, estimated at greater than 10 million people, become ill as a result of their travel.^3,4

With a heightened interest in adventure travel, international destinations, and ecotourism, more patients return from vacations with presentations of possible exotic disease that are beyond the scope of an emergency physician's daily practice. However, much of the illnesses encountered could be eliminated with adequate pre-travel education and preparation. In the circumstance when prophylactic treatment and lifestyle modification fail, physicians need to know what to look for and where to find information on exotic diseases beyond the scope of daily practice. Further information can be quickly and easily accessed through the CDC Yellow Book, an online resource providing country-specific information.

Pre-travel preparation

Whether the participant is on an excursion to Nepal, is serving at a medical mission in Belize, or is the adventure-seeking traveler, preparation is paramount to a successful venture. All people planning travel should become informed about the potential hazards of the countries they are traveling to and learn how to minimize any risk to their health. Forward planning, appropriate preventive measures, and careful precautions can substantially reduce the risks of adverse health consequences. Although the medical profession and the travel industry can provide a great deal of help and advice, the traveler is responsible to ask for information, to understand the risks involved, and to take the necessary precautions for the journey. In addition, consideration should be given to any underlying medical or comorbid condition of each traveler — as medications and emergency planning should be established prior to leaving.

Travelers should ascertain the associated travel health information for their specific itinerary several months in advance of departure. This should include general health information such as vaccine requirements, prophylactic medications, disease outbreaks, political environment, and medical resources.

Although often overlooked, dental, and for women, obstetric/gynecologic (OB/GYN), check ups are advisable before travel to developing countries for prolonged travel to remote areas. This is particularly important for people with chronic or recurrent dental or OB/GYN problems.

Approach to medical preparation for travel

Prior to departure for any extended or overseas travel, the following information should be obtained:

Travel information

Geographic itinerary
Duration and month(s) of travel
Urban travel versus rural travel
Anticipated living conditions
Purpose of travel
Medical care resources during travel

Personal health

Personal health status (eg, age, weight, pregnant)
Medications and allergies
Past medical history
Medical or physical limitations

Basic health travel kit

A medical kit is an essential item that should be carried by all travelers to developing countries or where local availability of such resources remains in doubt. The kit should include standard first-aid items, simple medications for common ailments, and any items specific for that traveler. In addition, consider having a list of medications along with a medical attestation signed by a physician authenticating the need of those medications for personal use. Standard toiletry items sufficient for the entire travel period are recommended.^5,6

First-aid items

Antiseptic wound cleanser
Antihistamines
Adhesive bandages/bandages
Eye drops/rewetting drops
Hand antiseptic
Insect repellent
Insect bite treatment
Medical tape
Nasal decongestant
Oral rehydration powder
Scissors and safety pins
Simple analgesics (eg, ibuprofen, acetaminophen)
Sterile gauze/dressing
Thermometer (oral/rectal)

Additional considerations

Antidiarrheal medication
Antifungal medication
Malaria prophylaxis
Personal medications (current medical illnesses)
Sleeping medications/sedatives
Water purifier/disinfectant

Resource utilization

Improvisation (ie, creative use of unusual supplies for diagnosing, treating, splinting, transporting) is an invaluable skill taught in Wilderness Medical Society (WMS) courses. Efficient use of medications lightens the medical kit. For example, rather than carrying multiple antibiotics of choice for several possible infections, consider carrying a medication, such as ciprofloxacin, which treats travelers' diarrhea (TD) as well as respiratory, wound, bladder, and other infections. Another example is diphenhydramine, which is excellent as an injectable local anesthetic as well as treatment for nausea, allergic reactions, and insomnia.

Unique circumstances

Physicians planning to serve as an expedition physician are advised to take a course provided by the WMS or a similar course by other providers. Detailed logistical planning, skills, equipment, medications, and resources for varied groups and destinations are beyond the scope of this article. Such information is readily available in both courses and textbooks from the WMS and the International Society of Travel Medicine (ISTM).

Almost any expedition has a unique set of possible emergencies, varying by destination and by the types of participants. Possible injuries and risks range from unusual envenomations and exotic flora and fauna to bear or shark attacks to snakebite or frostbite. Below is a list of possible scenarios that foster preparatory thought:

An extended expedition in the Rocky Mountains with a group of Boy Scouts
An emergency with a patient who has end-stage renal disease while aboard a luxury cruise ship
Team physician on an Everest expedition
Marine biology study of the Great Barrier Reef
A bird-watching group in the Amazon
A photo safari in Africa
A fishing trip to Alaska

Requisite emergency skills may vary based on location, weather, activities, and availability of medical care. A physician may need knowledge of unusual diseases and injuries specific to certain activities or locations. These could include extrication and rescue skills in various environmental situations and improvisational skills and treatment of many medical emergencies. Many of these skills can be easily identified with adequate travel preparation and an understanding of the environment in which one will be traveling. However, regardless of the level of preparation, unplanned emergencies often occur, and one's level of preparation may dictate the success with which care is provided.^7,8

Vaccination and Immunization

In anticipation of upcoming travel, it is essential that one is well educated regarding the regions that will be visited and how one's current level of health may be impacted. Vaccinations are a vital part of any preparatory process. Once the regions of anticipated travel are identified, scheduling a visit to one's doctor or a travel medicine provider is essential—ideally 4-6 weeks before the trip because most vaccinations require a period of days or weeks to become effective. Reviewing current recommendations for the region of travel is recommended prior to the scheduled medical appointment.^9,10 In addition, if uncertain regarding previous immunizations, variable tests are available to identify appropriate titer levels and whether updated boosters are indicated.¹¹

When discussing vaccinations, considering which are essential based on the region of travel and planned activities and what may be recommended is prudent. The CDC separates vaccines into 3 categories: required, recommended, and routine.

Routine vaccinations

Routine vaccinations are the immunizations that are routinely provided as a part of one's normal health maintenance. These vaccines are necessary for protection from diseases that remain common in many parts of the world, although infrequently in the United States. If you are uncertain if you are up-to-date on routine immunizations, check with your medical provider.

Recommended vaccinations

Recommended vaccinations are predicated on a number of factors including one's travel destinations, planned activities, season, previous immunizations, urban/rural location, one's age, and current health status. In general, these vaccinations are recommended to protect travelers from illnesses present in other parts of the world and to prevent the importation of infectious diseases across international borders.

Special considerations for aging, immune compromised, pregnant, immigrant, chronically ill, students, and disabled travelers are essential.

Required vaccinations

International Health Regulations requires yellow fever vaccination for travel to certain countries in sub-Saharan Africa and tropical South America. In addition, those traveling during the Hajj are required by the government of Saudi Arabia to obtain the meningococcal vaccination.

Common Medical Considerations

Whether dealing with altitude sickness, malaria, cholera, or dengue fever, having a basic understanding of the common illnesses specific to the region of travel is essential. However, the list of potential considerations globally is enormous and far beyond the scope of this section. A great resource to identify more specific information can be found online through the Diseases Related to Travel section of the CDC. However, one of the most commonly experienced illnesses related to travel is diarrhea.

Travelers' diarrhea

By far, the most common health risk for travelers, especially those visiting developing countries, is traveler's diarrhea (TD), which can range from mildly annoying to prolonged, painful, and debilitating. According to the US CDC, high-risk destinations include the developing countries of Latin America, Africa, the Middle East, and Asia. Persons at particular high-risk include young adults, immunosuppressed persons, persons with inflammatory bowel disease or diabetes, and persons taking H2 blockers or antacids.^4,1

Every year, the CDC reports that between 20% and 50% of international travelers (an estimated 10 million people) develop diarrhea, usually within the first week of travel. TD, however, may occur at any time while traveling, even after returning home. The primary cause is contaminated food or water, typically found in areas with poor sanitation.

Common symptoms of TD include the following:

Abrupt onset
Increased frequency, volume, and weight of stool
Altered stool consistency
Nausea and/or vomiting may be associated
Abdominal cramping, bloating, flatus
Fever
Malaise

Treatment of TD

Most cases are benign and resolve in 1-2 days without treatment. TD is rarely life threatening. Infectious agents are the primary cause of TD. Bacterial enteropathogens cause approximately 80% of TD cases. The most common causative agent isolated in countries surveyed has been enterotoxigenic Escherichia coli (ETEC). The natural history of TD is that 90% of cases resolve within 1 week, and 98% resolve within 1 month.

Although nearly 90% effective, antibiotics are not recommended as prophylaxis. Routine antimicrobial prophylaxis increases the traveler's risk for adverse reactions and for infections with resistant organisms. Antibiotics provide no protection against either viral pathogens or parasitic pathogens; therefore, they can give travelers a false sense of security. As a result, strict adherence to preventive measures is encouraged, and bismuth subsalicylate should be used as an adjunct if prophylaxis is needed.

Because TD is usually self-limiting, oral rehydration is often the only treatment recommended. Clear liquids are routinely recommended for adults. If a traveler develops 3 or more loose stools in an 8-hour period and has associated nausea, vomiting, abdominal cramps, fever, or blood in stools, they may benefit from antimicrobial therapy. Antibiotics are usually given for 3-5 days. Currently, fluoroquinolones remain the drugs of choice.⁶

Legal Issues

Malpractice and Good Samaritan laws differ from state to state and in foreign countries. Whether contracted to provide care for an expedition or volunteering at a medical clinic in a developing country, legal protection can vary as much as one's moral obligation to treat. Before understanding the specific nuances and details of medical liability with regard to wilderness and travel medicine, an understanding of the general framework is essential. However, this is a complex topic beyond the scope of this article. It is highly recommended to review the malpractice environment where care will be delivered, confirm the medical coverage, and assess the medical liability associated with the planned undertaking.

In general, physicians are required by law to keep a medical record of any prescription or treatment rendered anywhere. This includes prescriptions for a family member or giving an adhesive bandage for a blister to a stranger. In the unfortunate circumstance of a poor treatment outcome, a patient's signed release often will not protect a physician from a good lawyer or from a poorly informed jury. In the situation of unplanned medical care, one legal argument used against the Good Samaritan defense has been that possession of any medical equipment showed that the physician had planned to practice medicine and therefore was not protected by the Good Samaritan law. Situations may arise in which physicians feel a moral obligation to help but have no legal protection. Decide ahead of time where to draw the line.

Physicians who are paid to provide care to a group have increased liability and must ascertain the level of malpractice coverage. Even then, the insurer may limit coverage to a specified group, leaving the physician unprotected if he or she should treat an outsider dragged to the tent because someone heard that the group had a doctor.

Medical Tourism

Travel for the purpose of seeking health care is not new. There is a long history of travel to be near friends or family who can provide support during care and convalescence, or to seek more sophisticated or specialized care not available locally, often in a more developed area. "Medical tourism" refers primarily to a new phenomenon of travelers leaving family and friends to seek care abroad, often in less developed countries, along with the organizations that support or offer incentives for such travel.

Exact measures of numbers of travelers involved in medical tourism are difficult to obtain. In 2004, United States citizens born in the United States made up 56% of all overseas air travelers outbound from the United States, but they contributed a much smaller proportion (17%) of travelers who listed health treatment as the main purpose of the trip. The majority of health-seeking travelers that year were current United States citizens born outside the United States (46%), followed by non-United States citizens (36%). Residents born outside the United States have stated that health care needs, such as dentistry, are often included in visits home because of familiarity with care in the country of origin, the high cost of health care in the United States, and lack of insurance coverage.¹²

In 2006, approximately half a million international trips occurred in which health treatment was one purpose of the trip. As medical tourism continues to increase, physicians should be either familiar with up-to-date sources of information (eg, Travelers' Health) or referral options, and inquire whether or what role travel plays in their patient's life and medical care.

Cruise Ship Medicine

Travel by cruise ship often congregates large groups of people from different parts of the United States and the world. In such settings, diseases (influenza, measles, rubella, Norwalk virus, gastrointestinal illnesses) can spread from person-to-person contact. Additionally, if a ship comes to port and passengers disembark to sightsee, they may be at risk for other geographic specific diseases, although such risk is difficult to quantify. Note that certain diseases can be transmitted before symptoms are apparent and that some people who become ill while on a cruise ship may have been infected prior to travel. Add to that the complexity often seen with an increasingly mobile aging population with multiplemedical problems and one can see that staffing a medical facility on a cruise ship can present many unique challenges.

Historically, cruise ships were poorly staffed and equipped. Today, most cruise ships require a ship physician to have some emergency medicine experience. Many ships have minimal medications and few, if any, have laboratory or radiographic capabilities. However, some have mini–critical care units complete with monitors, ventilators, defibrillators/pacers, and appropriate medications. In general, the lack of resources can exhaust a physician's diagnostic and medical skills on a regular basis.

Common medical conditions include the following:

Sunburn
Alcohol intoxication
Seasickness
Minor orthopedic injuries
Diarrhea
Viral upper respiratory infections
Geographic specific illnesses
Exacerbation of common medical illnesses

Anyone who becomes ill while on a cruise ship should seek medical attention on board and see a health care provider upon returning home. Persons who are ill should limit contact with the general population on board as much as possible to reduce further spread of disease. Ship authorities should report infectious diseases of public health significance to state or federal health officials.

People planning cruise ship travel, especially those older than 65 years, those with acute or chronic illnesses, or those who are pregnant or breastfeeding should consult with a health care provider prior to travel for advice and possible preventive medication. Other measures to prevent the spread of infectious diseases on cruise ships include obtaining appropriate immunizations prior to leaving and frequent handwashing throughout the trip.

On the up side, cruise ship medicine is not all work and no play. Travel and entertainment opportunities are endless. The volume of patients seen and the level of illness may vary. Conversely, cruise ship epidemics may require the physician and staff to remain quarantined at sea for weeks. For more information on serving as a cruise ship physician, contact the ACEP Cruise Ship and Maritime Medicine Section.

Summary

Travel medicine is a dynamic field because conditions worldwide are subject to rapid change. Clinicians must maintain a current base of knowledge encompassing a wide variety of disciplines including epidemiology, infectious disease, public health, tropical medicine, immigrant and refugee health, and occupational medicine. As a unique and growing specialty, it has become necessary to establish standards of practice in the field. These standards have been established to identify the scope of competencies expected of travel medicine practitioners, guide their professional training and development, and ensure a uniform level of patient care.

Important points to consider prior to departing:

Consult a travel medicine professional before leaving home. They can provide vital information for staying healthy, updating vaccinations, and providing prophylactic and precautionary medications.
Know one’s medical limitations, and follow the precautions related to the planned travel comorbid conditions.
Colds are a common problem among tourists, especially when confined to crowded conditions (eg, buses, cruise ships). Practice exquisite handwashing and limiting personal contact with others to minimize contamination.
Sexually transmitted diseases are frequently associated with unsafe practices while traveling. Avoid unsafe sex to protect yourself and your partner.
Gastrointestinal disorders are very common ailments among travelers. Purified hydration and good hygiene are essential.
Be aware of those traveling with you and help them get the proper medical attention when necessary.
Remember you are visiting someone else's country. Respect them and be considerate so that they can make your trip a pleasant, enjoyable experience.

Useful Resources

Available resources

World Health Organization International Travel and Health
CDC Travelers' Health Automated Information Line (877) FYI-TRIP
CDC Travelers' Health
ACEP Cruise Ship and Maritime Medicine Section
International Society of Travel Medicine

Preparation for nonmedical emergencies

CDC Nonmedical Emergencies

Recommended texts

CDC Health Information for International Travel (The Yellow Book). Elsevier; 2008.
Rose SR, Keystone JS. 2006 International Travel Health Guide. 13th ed. Elsevier. (Available through Travel Medicine Inc for about $25. For more information, call [800] 872-8633.)
Auerbach PS. Wilderness Medicine: Management of Wilderness and Environmental Emergencies. 5th ed. Mosby; 2007.

References

Reed CM. Travel recommendations for older adults. Clin Geriatr Med. Aug 2007;23(3):687-713, ix. [Medline].
Leder K. Travelers as a sentinel population: use of sentinel networks to inform pretravel and posttravel evaluation. Curr Infect Dis Rep. Jan 2009;11(1):51-8. [Medline].
Bhadelia N, Klotman M, Caplivski D. The HIV-positive traveler. Am J Med. Jul 2007;120(7):574-80. [Medline].
Jong EC, Sanford CA. Travel and Tropical Medicine Manual. 4^th ed. WB Saunders Co; 2008.
Forgey WW, et al. Wilderness Medical Society: Practice Guidelines for Wilderness Emergency Care. 5^th ed. Globe Pequot; 2006.
Forgey WW. Travelers' Self-Care Manual. In: A Self-Help Guide to Emergency Medical Treatment for the Traveler. Diane Publishing Co: 1997.
Auerbach P. Management of Wilderness and Environmental Emergencies. 5^th ed. Mosby Year Book; 2007.
Jong EC, McMullen R. Travel medicine problems encountered in emergency departments. Emerg Med Clin North Am. Feb 1997;15(1):261-81. [Medline].
CDC, Kozarsky PE. Health Information for International Travel 2005-2006. Elsevier; 2005.
Keystone JS, et al. Travel Medicine: Expert Consult. Mosby; 2008.
Paulke-Korinek M, Rendi-Wagner P, Kundi M, Tomann B, Wiedermann U, Kollaritsch H. Pretravel consultation: rapid dipstick test as a decision guidance for the application of tetanus booster vaccinations. J Travel Med. Nov-Dec 2008;15(6):437-41. [Medline].
Reed CM. Medical tourism. Med Clin North Am. Nov 2008;92(6):1433-46. [Medline].

Keywords

public health, tropical medicine, wilderness medicine, malaria, traveler's diarrhea, general vaccinations, vaccinations before travel, travel illnesses, adventure travel, ecotourism, exotic disease, overseas travel, travel-related diseases, travel-related illness, cruise ship medicine

Contributor Information and Disclosures

Author

Bret A Nicks, MD, Assistant Professor, Assistant Medical Director, Department of Emergency Medicine, Wake Forest University Health Sciences
Bret A Nicks, MD is a member of the following medical societies: American Academy of Emergency Medicine, American College of Emergency Physicians, Christian Medical & Dental Society, Society for Academic Emergency Medicine, and Wilderness Medical Society
Disclosure: Nothing to disclose.

Coauthor(s)

Debra Slapper, MD, Consulting Staff, Department of Emergency Medicine, St Anthony's Hospital
Debra Slapper, MD is a member of the following medical societies: American Academy of Emergency Medicine
Disclosure: Nothing to disclose.

Medical Editor

James Li, MD, Former Assistant Professor, Division of Emergency Medicine, Harvard Medical School; Board of Directors, Remote Medicine
Disclosure: Nothing to disclose.

Pharmacy Editor

Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine
Disclosure: Nothing to disclose.

Managing Editor

Eric L Weiss, MD, DTM&H, Director of Stanford Travel Medicine, Medical Director of Stanford Lifeflight, Assistant Professor, Departments of Emergency Medicine and Infectious Diseases, Stanford University School of Medicine
Eric L Weiss, MD, DTM&H is a member of the following medical societies: American College of Emergency Physicians, American College of Occupational and Environmental Medicine, American Medical Association, American Society of Tropical Medicine and Hygiene, Physicians for Social Responsibility, Southeastern Surgical Congress, Southern Association for Oncology, Southern Clinical Neurological Society, and Wilderness Medical Society
Disclosure: Nothing to disclose.

CME Editor

John D Halamka, MD, MS, Associate Professor of Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center; Chief Information Officer, CareGroup Healthcare System and Harvard Medical School; Attending Physician, Division of Emergency Medicine, Beth Israel Deaconess Medical Center
John D Halamka, MD, MS is a member of the following medical societies: American College of Emergency Physicians, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: Nothing to disclose.

Chief Editor

Rick Kulkarni, MD, Medical Director, Assistant Professor of Surgery, Section of Emergency Medicine, Yale-New Haven Hospital
Rick Kulkarni, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Emergency Medicine, American College of Emergency Physicians, American Medical Association, American Medical Informatics Association, Phi Beta Kappa, and Society for Academic Emergency Medicine
Disclosure: WebMD Salary Employment

Further Reading