Anne E. McCarthy

Unique Considerations for Long-Term Travel

A prolonged stay of 6 months or more in low- and middle-income countries, whether for tourism or employment purposes, leads to an increase in the risk of travel and non-travel-related illness. The risk includes both infectious diseases and trauma, due in part to the cumulative risk over months to years of potential exposure. Any illness may necessitate interaction with the local health-care system, which may have limited resources.

The most commonly reported health problems in long-term travelers include diarrheal diseases, respiratory illness, and skin conditions. Infectious diseases, although important causes of morbidity, are not common causes of travel-related mortality, even in long-term travelers. A Canadian study of international travel-related death documented the rare occurrence due to vaccine-preventable or exotic disease. Similarly, a U.S. study found that those residing abroad were more likely to sustain fatal injuries, particularly due to motor vehicle crashes and drowning, suggesting that time should be spent educating these travelers about road and water safety.

Those spending prolonged periods abroad are likely to eventually relax preventive measures, resulting in increased risk of acquiring vector-, food-, and water-borne diseases. This risk will in turn lead to an increased chance of requiring local medical care, which may have limited resources (personnel and therapeutic) and may have suboptimal therapy (such as counterfeit or poor-quality medications). Approximately 3% of >4,000 UK diplomats living overseas required medical evacuation, most (70%) of which were due to unsuitable medical facilities.

Pre-Travel Care

Providing pre-travel care for these special-needs travelers includes prevention strategies, as well as therapy for illness that may be inevitable with time.

• Prior to departure, all long-term travelers should undergo an extensive medical and dental examination to exclude underlying disease.
• The pre-travel consultation for long-term and expatriate travelers should include consideration of vaccine-preventable and other diseases, discussion about acquiring medical care while abroad, and appropriate medical care and evacuation insurance.
  • With prolonged travel, there may be more than just the immediate destination to consider, since over time there may be travel to surrounding regions and possibly repeated short-term exposures that translate into significant cumulative risk.
  • Expatriates often live in areas or cities with low or negligible infectious risks but take frequent recreational or business trips to regional destinations with increased risk.

Vaccine-Preventable Infectious Diseases

Routine vaccines, including influenza vaccination, should be updated. As well, a number of travel-related vaccines warrant consideration.

• Hepatitis A and typhoid vaccines are appropriate given the cumulative risk, although the traveler should be aware that the latter does not provide full protection.
• Hepatitis B vaccine is increasingly provided in the United States; however, many adults may not have protection. They may be at substantial risk, as demonstrated by a survey of mostly short-term travelers, where 15% of 400 travelers had potential blood and body fluid exposure.
• Meningococcal disease is more likely in travelers with prolonged exposure to local populations in endemic or epidemic areas; quadravalent vaccine should be considered for those at risk.
• Japanese encephalitis vaccine is costly and is usually recommended for travelers with prolonged rural exposure; however, the potential for travel outside the primary destination must be considered in light of the possible cumulative risk.
• Rabies prevention is of increased importance with prolonged residence in endemic countries. Foreign residents in Nepal reported an exposure risk of 5.7/1,000 persons/year, compared with 1.9 per 1,000 persons/year for tourists. Rabies prevention strategies are complicated by the cost and availability of pre-exposure vaccine and by the potential lack of availability of safe or effective postexposure prophylaxis in some countries. In one survey, only 38% of 293 missionary personnel stationed abroad had received pre-exposure prophylaxis. More concerning was that just 8% of the 38 potential exposures received appropriate postexposure care.

Non-Vaccine-Preventable Infectious Diseases

Malaria

Standard strategies appropriate for malaria prevention in short-term travel may need to be modified and adapted for those with long-term malaria risk. These travelers or expatriates often do not optimize personal protection measures for bite avoidance (insect repellents and insecticide-treated nets and clothing) on a daily basis and adhere poorly to continuous prophylaxis regimens or do not wish to take medications long term. A retrospective cohort analysis study conducted by reviewing pharmacy records and by interviews in person of chemoprophylaxis adherence in 183 expatriate households in coastal Nigeria showed that only 127 (69%) collected their prophylaxis regularly, and overall only 39% of households were compliant. Many cited concerns about the real and perceived risks for adverse drug reactions, particularly with long-term use.

There are no consensus guidelines on the prevention of malaria in long-term travelers. Many different malaria prevention strategies have been recommended, such as initial prophylaxis followed by discontinuation or intermittent use at times of higher risk (seasonal chemoprophylaxis) If the long term traveler chooses not to take chemoprophylaxis, they should have good access to medical care and seek medical attention when sick for the best quality diagnosis and treatment (see the Malaria section in Chapter 2).

Long-term travelers—

• Must be aware of their risk.
• Should optimize bite prevention with the use of window screens and bed nets.
• Should be educated on malaria symptoms and the need to seek early medical attention for a febrile illness.

Other Diseases

Diarrhea and gastrointestinal diseases are common in long-term travelers residing in the tropics, and these individuals should be educated about the management of acute diarrhea, including rehydration, the use of antimotility agents, and empiric antimicrobial therapy. Prolonged diarrhea is more suggestive of a protozoal etiology.

HIV and sexually transmitted infection risks have increased in travelers and expatriates. Furthermore, the consistent use of condoms in expatriates is low (around 20%). Long-term travelers should be educated about the risk of HIV and STDs in their destination. The potential for occupational exposure to HIV is important to consider in health-care workers; postexposure prophylaxis with highly active antiretroviral therapy and risk avoidance should be included in the pre-travel consultation (see the Occupational Exposure to HIV section in Chapter 2).

Transfusion is an important risk for hepatitis C infection in expatriates. The risk of hepatitis E, spread by the fecal-oral route, is highest in Asia, although it has been transmitted in many different tropical locations. Pregnant women are at highest risk of fulminant disease. Other infections vary with location and include schistosomiasis, which may be prevented by not swimming or wading in fresh water. Tuberculosis risk eventually equates to that of the local population, increasing with length of stay and contact with the local population.

Summary

Long-term travelers and expatriates require realistic and individualized pre-travel counsel on the prevention and management of infectious and noninfectious illnesses. The need for eventual medical care should be anticipated, and strategies to reduce the risk of counterfeit or ineffective medication should be discussed.

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