Long-Term Travelers and Expatriates

Introduction

The risk for illness or injury increases with duration of travel, so travelers planning long-term (commonly considered ≥6 months) visits to low- or middle-income countries require special consideration regardless of whether they are expatriates with definite plans or adventurers with open itineraries. Points to discuss in the pre-travel consultation include accessing routine and emergency care at the destination, vaccines, infectious diseases not prevented by vaccines, injury prevention, and cultural and mental health issues that long-term travelers might encounter.

Accessing care abroad

Before departure, all long-term travelers should undergo complete medical and dental examinations. For expatriates, a mental health evaluation prior to travel could identify and help address underlying issues that often cause early repatriation (see Mental Health in Travelers chapter). Travelers should anticipate that they will need care at some point during their stay and plan where they will obtain it and how they will pay for it.

People traveling for work or with an organization (e.g., a nongovernmental organization, Peace Corps, a university) might have a predetermined source for care; some might access advice from the international expatriate community. By contrast, other travelers should identify a healthcare source in advance (see What to Do When Sick Abroad chapter). Long-term travelers also should determine whether they will need supplemental travel health insurance and evacuation insurance (see Travel Insurance, Travel Health Insurance, and Medical Evacuation Insurance chapter).

In some countries, travelers are likely to encounter medications of poor quality that are substandard, falsified, counterfeit, or expired. Because the pills and packaging could be nearly indistinguishable from their legitimate counterparts, travelers should bring a sufficient supply of their routine medications (e.g., antihypertensive or antihyperlipidemic drugs) from the United States. The traveler bringing a large supply of their routine medications should obtain a letter of necessity from the prescribing provider, which is especially important for psychotropic medications (see Traveling with Prohibited or Restricted Medications chapter).

Controlled substances and certain over-the-counter and commonly prescribed medications are illegal to bring into some countries (see Traveling with Prohibited or Restricted Medications chapter). The International Narcotic Control Board website includes guidelines provided by each country and is a good reference for travelers looking for information about whether they can legally import their medications to their destinations (Table 8.4.1).

Options for obtaining sufficient medications include: requesting an override from the insurance company to dispense the entire quantity of medication; paying out of pocket for the full amount of medication needed and then submitting to the insurance company for reimbursement; or refilling prescriptions during trips home.

Table 8.4.1: Importing medications for personal use

Vaccines

Long-term travelers should be aware of any vaccine requirements for entry, employment, or schooling at their destination. Update routine vaccines, including influenza and COVID-19 vaccines, before travelers depart, and consider disease risk in surrounding areas because long-term travelers are likely to travel locally. A short-term traveler to Seoul, for example, would not be considered at risk for Japanese encephalitis (JE), but expatriates living in Seoul might have opportunities to visit the Korean countryside or other areas in Asia where they could be exposed to the JE virus. Similarly, consider yellow fever vaccination, even if the posting location is not in an endemic area, because the traveler might journey to endemic areas while living abroad.

Hepatitis A and typhoid fever

Given the cumulative risk for hepatitis A and typhoid fever infection among long-term travelers, vaccination against these two diseases is appropriate (see Hepatitis A and Typhoid and Paratyphoid Fever chapters). Neither of the U.S. Food and Drug Administration (FDA)-approved typhoid vaccines, however, effectively prevents infection in all recipients. The injectable (ViCPS) vaccine and the oral (Ty21a) vaccine are each estimated to protect approximately 50%–80% of recipients from infection. Thus, travelers who receive these vaccines should still adhere to safe food and water precautions (see Food and Water Precautions for Travelers chapter). Moreover, duration of protection afforded by each vaccine is limited; a repeat dose of ViCPS is recommended every 2 years for travelers at continued risk of infection. Some countries have approved ViCPS for 3 years of protection and a 3-capsule course of Ty21a for 3 years of protection. For Ty21a recipients in the United States who have received a 4-capsule regimen, revaccination is recommended every 5 years.

Hepatitis B

Travel-associated hepatitis B virus infections are rare, but the risk for travelers might be greater than for non-travelers, especially for long-term travelers and expatriates, so consider hepatitis B vaccine for this population. Recommendations for vaccination against hepatitis B for the U.S. population have also evolved over time. Currently, hepatitis B vaccination is recommended for all persons through 59 years who have not been vaccinated, and adults aged 60 years or older with risk factors for hepatitis B virus infection. Adults who are 60 years or older without known risk factors for hepatitis B may also receive hepatitis B vaccine.

Japanese encephalitis

Infection with JE virus is associated with longer stays in endemic areas. JE vaccine is recommended for travelers who plan longer stays or residence in endemic areas, travelers anticipating outdoor activities in endemic areas after dusk, and travelers who are uncertain of specific destinations or activities (see Japanese Encephalitis chapter).

Meningococcal

Meningococcal disease is more likely in travelers with prolonged exposure to local populations in endemic or epidemic areas; consider quadrivalent conjugate vaccine for at-risk travelers, including individuals traveling to the meningitis belt in Sub-Saharan Africa (see Meningococcal Disease chapter).

Rabies

Rabies pre-exposure prophylaxis is an important consideration for people spending prolonged time in endemic countries, especially in places where rabies immune globulin is not available, which is true of many low- and middle-income countries. Prioritize vaccination for children who will be living in high-risk areas (see the Rabies chapter and Rabies Status Assessment by Country).

Tick-borne encephalitis

Infection with tick-borne encephalitis (TBE) virus may be associated with longer stays in endemic areas (see Tick-Borne Encephalitis chapter). TBE vaccine may be considered for persons who are moving or traveling to a TBE-endemic area and will have extensive exposure to ticks based on their planned outdoor activities and itinerary.

Yellow fever

Yellow fever vaccination might be required by some countries or recommended for endemic areas (see the Yellow Fever Vaccine and Malaria Prevention Information, by Country, and Yellow Fever chapters). For instance, numerous unvaccinated Chinese expatriates became ill with yellow fever while working in Angola during the outbreak there in 2016, illustrating the importance of yellow fever vaccination for people who will be living or working in endemic areas.

Dengue and chikungunya

Dengue seroconversion among long-term travelers from the Netherlands with median travel duration of 20 weeks was 6.5% with an incidence of 13.9 per 1,000 person-months travel in endemic areas. Chikungunya also poses a potential risk. Advise long-term travelers and expatriates to protect themselves from mosquito vectors (see Mosquitoes, Ticks, and Other Arthropods chapter). The dengue vaccine that is U.S. FDA-licensed is recommended only for persons residing in endemic areas who have confirmed prior dengue virus infection; it is not indicated for travelers, and its availability will cease in 2026. A chikungunya vaccine is recommended for adults traveling to countries with a current outbreak and may be considered in other scenarios (for details, see the Dengue, and Chikungunya chapters).

Infectious diseases not prevented by travel vaccines

Hepatitis C and Hepatitis E

Transfusion is a potential source of hepatitis C virus infection in expatriates. Hepatitis E virus is spread by the fecal-oral route; the risk for infection is greatest in Asia, although it has been transmitted in many different tropical locations. Pregnant women are at greatest risk for fulminant disease from hepatitis E.

HIV and sexually transmitted infections

Travelers and expatriates have been shown to have increased risk for HIV and sexually transmitted infections (STIs), and the consistency of condom use among expatriates is low (see Sex and Travel chapter). Educate long-term travelers about the risk for HIV and STIs at their destination, as well as preventive measures including HIV pre-exposure prophylaxis. Consider the potential for occupational exposure to HIV among healthcare professionals, and during the pre-travel consultation include discussions of post-exposure prophylaxis with antiretroviral therapy and risk avoidance (see International Travel to Deliver Health Care in Resource-Limited Settings chapter).

Malaria

For long-term travelers, emphasize the importance of insect bite avoidance (e.g., use of long-lasting insecticide-treated bed nets, staying inside in rooms with screens; see Mosquitoes, Ticks, and Other Arthropods chapter). Even when urged to adhere to personal protective measures and reassured that long-term prophylaxis is safe and effective, traveler adherence likely will decline over time. Consequently, the pre-travel consultation for a long-term traveler to malaria-endemic areas should stress the severity of the disease, its signs and symptoms, and the need to seek care immediately if signs and symptoms develop. Travelers also can consider bringing a reliable supply of drugs to treat malaria (artemether-lumefantrine or atovaquone-proguanil) if they are diagnosed with the disease (see the Yellow Fever Vaccine and Malaria Prevention Information, by Country, and Malaria chapters).

Risk factors contributing to infection

Evidence, albeit limited, suggests that malaria incidence increases and use of preventive measures decreases with increasing length of stay abroad. For example, among expatriate corporate employees in Ghana, adherence to malaria prophylaxis deteriorated with increasing duration of stay, and all employees who had been on the site for >1 year had abandoned prophylaxis. About half of the cohort only intermittently used insect repellent, and more than 1/3 never used repellent.

Even though most British expatriates from the UK Foreign and Commonwealth Office had good knowledge about malaria and its prevention strategies, they adhered to malaria prophylaxis <25% of the time; only 25% reported rigorous compliance, and 13% reported having contracted malaria. The International Red Cross also reported low compliance (43%) to malaria prophylaxis among its humanitarian aid workers. A recent GeoSentinel Surveillance Network analysis found that Plasmodium falciparum malaria was the most frequent diagnosis among ill returned expatriate workers, occurring in 6%, and was acquired most commonly in Sub-Saharan Africa. Given the high risk for malaria among travelers in Africa, these data on long-term travelers and expatriates highlight worrisome risks and practices.

French service members deployed to the Central African Republic for 4 months in 2013 experienced malaria at a rate of 150 cases per 1,000 person-years. A survey found that prophylaxis compliance correlated positively with use of other prophylactic measures against malaria (e.g., insecticide-treated clothing, mosquito net use, taking prophylaxis at the same time every day), correct perception of malaria risk, favorable perception of prophylaxis effectiveness, and peer-to-peer reinforcement.

Chemoprophylaxis

A traveler residing in an area of continuous malaria transmission should use malaria prophylaxis for the entire stay (see Malaria chapter). Doxycycline has been well-tolerated for long-term malaria prophylaxis in the military, and the Centers for Disease Control and Prevention (CDC) has no recommended limits on its duration of use for malaria prophylaxis. Mefloquine might be appropriate for long-term prophylaxis in chloroquine-resistant areas because of its convenient weekly dosing, but concern has increased regarding its neuropsychiatric side-effect profile, especially because the FDA black box warning indicates that neurologic side effects could persist.

Atovaquone-proguanil has shown good long-term tolerability in post-marketing surveillance, with a discontinuation rate of only 1% because of diarrhea. For long-term use, however, atovaquone-proguanil can be a more expensive option than other antimalarial drugs. Peace Corps volunteers prescribed atovaquone-proguanil adhered to prophylaxis better than did people given doxycycline or mefloquine. In the limited malaria-endemic areas where chloroquine is still effective and extended (>5 years) use of chloroquine is planned, a baseline ophthalmic examination with biannual follow-up is recommended to screen for potential retinal toxicity.

Because of its convenient weekly dosing, the antimalarial drug tafenoquine may be useful for some long-term travelers. Tafenoquine use should be avoided in people with documented glucose-6-phosphate-dehydrogenase (G6PD) deficiency, as well as in those who have not been tested for G6PD deficiency. It is also not recommended for use in people with a history of psychotic disorder. Pregnancy is a contraindication to tafenoquine use.

Pregnancy

The possibility of pregnancy requires careful consideration for travelers to areas where malaria is endemic (see the Malaria and Pregnant Travelers chapters). Malaria during pregnancy can result in severe complications to both mother and fetus. When pregnancy is anticipated, prophylaxis options might need to be adjusted; explore the possibility of pregnancy with all long-term travelers of childbearing potential before departure.

For a woman who is pregnant or who plans to become pregnant during long-term travel, mefloquine is considered safe in all trimesters. Data from published studies in pregnant women have shown no increase in the risk for teratogenic effects or adverse pregnancy outcomes after mefloquine prophylaxis during pregnancy. Chloroquine also has been used long-term without ill effects on pregnancy. If a woman traveling long-term is taking atovaquone-proguanil, doxycycline, or primaquine, she should discontinue their medication and begin weekly mefloquine (or chloroquine in those areas where it remains efficacious) for at least 3–4 weeks to build up a therapeutic blood level of mefloquine before attempting to conceive.

During the pre-travel consultation, advise women of the potential risks associated with becoming pregnant while taking antimalarial drugs. Doxycycline, for example, is associated with fetal toxicity in animal studies, and its use is contraindicated during pregnancy. Primaquine and tafenoquine can harm a G6PD-deficient fetus, so should not be used during pregnancy regardless of the mother's G6PD-status. The effect of atovaquone-proguanil on the fetus is unknown.

Other parasitic infections

Longer duration of travel may be associated with greater exposure to parasitic infections such as amebiasis, filariasis, giardiasis, cutaneous leishmaniasis, schistosomiasis, and strongyloidiasis. The risks also vary with location. Vector-borne infections (e.g., filariasis, cutaneous leishmaniasis) can be prevented by using insect bite precautions and protective clothing, and by avoiding locations where the vectors are prevalent (see Leishmaniasis chapter). For travelers with appropriate (or potential) geographic exposure risks, consider the possibility of filariasis and cutaneous leishmaniasis.

Travelers can avoid schistosomiasis (see Schistosomiasis chapter) by not bathing, swimming, or wading in untreated freshwater; this guidance can be difficult to communicate to long-term travelers who, for example, might be living in Sub-Saharan Africa and are looking forward to river rafting or vacationing at a lake. Travelers can prevent Strongyloides stercoralis and hookworm infections by not walking barefoot on soil. The risks for schistosomiasis and strongyloidiasis can increase with long-term travel; consider screening travelers on their return and suggest that people with access to health care also seek screening during long-term expatriate assignments (for details, see Perspectives: Screening Asymptomatic Travelers chapter).

Avoiding unwashed or uncooked foods, including greens and vegetables, can help reduce a traveler's chances of ingesting foodborne parasites (e.g., Ascaris; see Food and Water Precautions for Travelers chapter).

Travelers' diarrhea

Because diarrhea and gastrointestinal diseases occur commonly (in up to 80% or more of long-term expatriates), educate long-term travelers about ways to manage gastrointestinal illnesses (see Travelers' Diarrhea chapter), including rehydration, use of antimotility agents, indications for empiric antimicrobial therapy, and knowing when to seek care.

Compared with short-term travelers, long-term travelers experience more chronic diarrhea and postinfectious irritable bowel syndrome, possibly because some become less adherent to food and water precautions over time (see Post-Travel Diarrhea chapter). Advise travelers of the need to continue food and water precautions to reduce the risk for these conditions (see Food and Water Precautions for Travelers chapter).

Tuberculosis

In destinations where the burden of tuberculosis (TB) is high, the risk of infection in travelers could rise to that of the local population, depending on their length of stay and closeness of contact with the local population (see Tuberculosis chapter). For long-term travelers, consider a baseline interferon-gamma release assay before travel and repeat the same test after travel. The utility and the need for serial testing during long-term stays are unknown; some experts have suggested testing every 6 months for persons who work in places with ongoing TB exposures. In some settings, the tests are not consistently available, or the tests that are available are different from those in the United States, which confounds the interpretation of a conversion. TB screening is particularly important for healthcare professionals or people working in hospitals, prisons, or refugee camps (see Pre-Arrival Medical Screening and Interventions for Newly Arrived Refugees, Immigrants, and Migrants chapter).

Injury

Because injuries are the leading cause of preventable death in travelers, educate long-term travelers about safety. Stress the importance of road and vehicle safety, and emphasize that travelers should choose the safest vehicle options available. Roads in some areas can be poorly constructed and maintained, traffic laws might not be enforced, vehicles might not have seatbelts or be kept in good condition, and local drivers might be reckless and minimally trained (see the Injury and Death During Travel chapter for strategies to reduce the risk of traffic and other injuries).

Mental health

Culture shock and the stress of long-term travel can trigger or exacerbate mental illness (see Mental Health in Travelers chapter). Assess long-term travelers for a preexisting diagnosis of mental illness, depressed mood, recent major life stressors, and use of medications that can adversely affect mental health. Any of these conditions suggest a need for further screening or evaluation by a mental health provider pre-departure and a plan for appropriate care while abroad.

Warn all long-term travelers against illicit drug use and urge them to take care of their physical and mental health by exercising regularly and eating healthfully (see Substance Use and Substance Use Disorders in Travelers chapter). Travelers should be able to recognize signs of anxiety and depression and have a plan for coping. Having photographs or other mementos of friends and family at hand, and staying in close contact with loved ones at home, can alleviate the stress of long-term travel.

Long-term travelers with open itineraries

Offering pre-travel care to long-term travelers, especially travelers with no itinerary or who have only vague travel plans, presents unique challenges. These travelers benefit from broad immunization coverage for all potential exposures to vaccine-preventable diseases.

Because their plans are unclear, these travelers must understand that they might need to diagnose and treat themselves for common ailments, including musculoskeletal problems, upper respiratory tract infections, skin disorders, travelers' diarrhea, urinary tract infections, and vaginitis. For travelers (e.g., backpackers) who might go in and out of malaria-endemic areas, a sensible approach is to provide a supply of an antimalarial agent such as atovaquone-proguanil or doxycycline with instructions on determining areas endemic for malaria (see Yellow Fever Vaccine and Malaria Prevention Information, by Country chapter) and how to take the medication when they visit risk areas.

In addition to strategies to prevent health problems and injuries during their long sojourns, traveler education is imperative regarding health resources, signs and symptoms that require urgent medical evaluation, and medical evacuation.

Screening long-term travelers and expatriates after return

After returning to their country of origin, long-term travelers (e.g., highly adventurous travelers, expatriate workers, Peace Corps volunteers) ideally should have a thorough medical interview to assess potential infectious exposures. A careful itinerary-specific history with detailed questioning about potential high-risk exposures, including animal, food and water, and human contacts, is the foundation of the post-travel evaluation.

Conduct a physical examination focused on specific signs and symptoms and obtain a selected array of tests. These tests typically include a complete blood count with differential, hepatic transaminases, stool ova and parasite examination, and serologic markers depending on types of exposure, but most importantly for schistosomiasis and strongyloidiasis. Serologic testing can detect subclinical infections and help identify instances where treatment would be advised (see Perspectives: Screening Asymptomatic Travelers chapter). The post-travel evaluation also provides an opportunity for preventive counseling for potential future travel.