Before going abroad to areas that might pose a risk to their health, most people ought to visit their primary care physicians and many should be referred to a specialist in travel medicine.
In this article, we review the key elements of the pretravel consult as it relates to the prevention and self-treatment of the most common diseases that pose health risks for travelers. We also give guidelines for when to refer patients to a specialist.
WHY PRIMARY CARE PHYSICIANS NEED TO KNOW TRAVEL MEDICINE
International travel to exotic locations is becoming more popular. In 2008, one out of five Americans traveled abroad, and 38 million visits were to developing countries where there are significant health risks for travelers.1
One third to one half of travelers to developing countries experience some kind of illness while abroad, most commonly diarrhea or upper respiratory infections, which typically lead to 3 lost days during a 2-week trip.
These illnesses are often preventable and self-treatable.2 Unfortunately, studies suggest that most travelers do not seek adequate medical advice, and that when they do they often fail to complete courses of medication.3,4
All these factors point to the need for primary care providers to become proficient in the pretravel consult and, if necessary, to refer patients to travel specialists and clinics.
WHY REFER TO A TRAVEL CLINIC?
In one study of travelers to areas of high risk for malaria or hepatitis A, 42% of those who consulted only their family doctor became ill, in contrast to 22% of those who attended a travel medicine clinic.4
As a rule of thumb, anyone traveling to an area where malaria is endemic should be referred to a specialist, as should anyone at risk of yellow fever or typhoid fever. As many as 8 per 1,000 travelers may return from areas of risk infected with malaria.5
Long-term travelers and people who will spend time in urban slums or rural or remote regions have an even greater need for referral to a travel clinic, as they are at higher risk of exposure to Japanese encephalitis, cholera, epidemic meningitis, dengue fever, and rabies.6
THE PRETRAVEL CONSULT: ESSENTIALS
A pretravel consult ought to be scheduled 4 to 6 weeks in advance of the trip, since many vaccines require that much time to induce immunity, and some require a series of shots.
Unfortunately, many patients who think of arranging a travel consult make the appointment at the last minute, and some come with an incomplete knowledge of their travel plans. However, even without enough advance notice, a consult can be beneficial.
Travelers sometimes change their itineraries in-country or engage in unanticipated risky behaviors. A good travel medicine physician tries to anticipate even these unplanned risks and changes in itinerary.
Where is the traveler going? When? For how long?
The pretravel consult starts with a detailed discussion of the patient’s itinerary. It needs to include length, dates, and location of travel, as well as anticipated activities and accommodations.
A remarkable number of travelers come to consults not knowing the names of specific countries they will visit, perhaps saying only that they are going to Africa or South America. An accurate itinerary is indispensible, as appropriate medical advice is highly specific to country and region. The incidence and geographic distribution of many travelers’ diseases change over time, and this requires physicians to consult the most current information available.
Tropical countries, in general, are risky, but each pathogen has a unique distribution that may vary between urban and rural areas or by season. Detailed, up-to-date information is available from the US Centers for Disease Control and Prevention (CDC) (www.cdc.gov) for individual countries and for specific provinces and locations within those countries. Physicians should consult the CDC whenever advising a patient preparing to travel. 7
How is the traveler’s current health?
Several immunizations cannot be given to the very young, the elderly, or those who are immunocompromised.
The greatest risk of death to travelers is not from tropical diseases but from cardiovascular disease, which according to one study is responsible for half of deaths abroad.8 Patients with heart disease or other known health concerns need to be counseled to avoid activities that will put them at further risk. The advice applies especially in situations such as remote travel or even cruises, where prompt emergency medical care may be difficult or impossible to obtain.
People infected with human immunodeficiency virus (HIV) face discriminatory travel prohibitions in 74 countries.9
Foreign-born travelers who are visiting family and friends in developing countries may have lost their immunity to local pathogens and thus can be more at risk because they are not prepared to take necessary health precautions.
Also, a significant number of travelers become infected but develop illnesses only after they return, so a posttravel visit may be necessary.6
Prescription and even over-the-the-counter drugs may be difficult or impossible to obtain in foreign countries, and ample supplies should be brought along.
Is the traveler up to date on routine immunizations?
A number of infectious diseases that have been controlled or eradicated in North America through regular childhood immunizations are still endemic in many remote areas and developing countries. All travelers should be up to date on routine immunizations, including those for measles-mumps-rubella, tetanus, polio, meningitis, and hepatitis A and B.
Polio. A one-time polio booster is recommended for adults traveling to certain countries or areas of the world.
Meningitis vaccine is now routinely given to young people, but adult patients may need it before they travel.
Hepatitis A is contracted through fecal contamination of food and water. Common sources are foods prepared in an unhygienic manner, raw fruits and vegetables, shellfish, and contaminated water.
Hepatitis B vaccine is also now routinely given to young people, but it should be offered to travelers planning to stay more than 1 month and to long-term expatriates. This vaccine is also recommended for travelers who may be exposed to blood or body fluids, who are contemplating sexual activity or tattooing in the host country, or who may require medical or dental care while traveling, as well as for adventure travelers or travelers to remote regions.
The vaccination is given in a three-dose schedule at 0, 1, and 6 months. For protection against both hepatitis A and B, the vaccine Twinrix can be used on the same schedule as for hepatitis B. An accelerated schedule of 0, 7, and 21 days with a booster at 12 months allows completion of the entire series in 4 weeks, thus putting completion of vaccination before travel in the same time frame as other vaccines in a series, such as those for rabies and Japanese encephalitis.