A traveler categorized as a VFR is an immigrant, ethnically and racially distinct from the majority population of the country of residence (a higher-income country), who returns to his or her home country (lower-income country) to visit friends or relatives. Included in the VFR category are family members, such as the spouse or children, who were born in the country of residence. Some experts have recommended that the term VFR refer to all those visiting friends and relatives regardless of the traveler’s country of origin; however, this proposed definition may be too broad and not take into consideration cultural, economic, and attitudinal issues. Therefore, this review uses the more classic definition.
Altered migration patterns to North America in the past 30 years have resulted in many immigrants originating from Asia, Southeast Asia, and Latin America instead of Europe. Although 13% of the US population is foreign born, in 2014, 37% of overseas international travelers from the United States listed VFR as a reason for travel. VFRs experience a higher incidence of travel-related infectious diseases, such as malaria, typhoid fever, tuberculosis, hepatitis A, and sexually transmitted diseases, than do other groups of international travelers, for a number of reasons:
In 2012, 54% of imported malaria cases in US civilians occurred among VFRs. Data from the GeoSentinel Surveillance Network show that among ill travelers who present for medical care, VFRs are 8 times more likely to be diagnosed with malaria than are tourist travelers. Reports from the United Kingdom show similar results for VFR versus tourist travelers to West Africa. Many VFRs assume they are immune; however, in most VFRs, especially those who left their countries of origin years previously, immunity has waned and is no longer protective. In recent years, a number of VFRs have died of malaria on their return to North America; in the United States in 2012, 55% of those with severe malaria for whom the purpose of travel was known were VFRs, mostly returned from West Africa.
From 2008 through 2012 in the United States, 85% of typhoid and 88% of paratyphoid A cases occurred in VFRs, mostly from southern Asia. Most isolates were resistant or showed decreased susceptibility to fluoroquinolone antibiotics. Similar rates of resistant infections were noted in imported cases in Switzerland from the Indian subcontinent.
VFR children aged <15 years are at highest risk for hepatitis A, and many are asymptomatic. A Canadian study found that 65% of hepatitis A cases were in VFRs aged <20 years, and in a Swedish study of 636 cases of imported infection, 52% were in VFRs, of whom 90% were <14 years old. Other diseases, such as tuberculosis, hepatitis B, cholera, and measles, occur more commonly in VFRs after travel.
Table 8-4 summarizes VFR health risks and prevention recommendations. It is important to increase awareness among VFR travelers regarding their unique risks for travel-related infections and the barriers to travel health services. If possible, clinics should incorporate culturally sensitive educational materials, provide language translators, and provide handouts in multiple languages. However, studies in the United Kingdom aimed at preventing malaria among VFRs showed that increased awareness and availability of medications do not necessarily increase use of malaria chemoprophylaxis, highlighting the complex socioecological context in which VFRs make travel health decisions.
|Diseases||Reason for Risk Variance 2||Recommendations to Stress with VFR Travelers|
|Foodborne and waterborne illness||Social and cultural pressure (eat the meal served by hosts)|
|Fish-related toxins and infections||Avoidance counseling about specific foods (such as raw freshwater fish)|
|Tuberculosis (particularly multidrug-resistant)|
|Bloodborne and sexually transmitted diseases|
|Schistosomiasis and soil-transmitted helminths||Limited access to piped-in water in rural areas for bathing and washing clothes|
|Respiratory problems||Increased close exposure to fires, smoking, or pollution||Prepare for asthma exacerbations by considering stand-by bronchodilators and steroids|
|Zoonotic diseases (such as rickettsial infections, leptospirosis, viral fevers, leishmaniasis, anthrax, Chagas disease)|
|Envenomations (snakes, spiders, scorpions)||Sleeping on floors|
|Toxin ingestion (medication adverse events, heavy metal ingestion)|
|Yellow fever and Japanese encephalitis (risk is decreased in adults)||Unclear, partial immunity from previous exposure or vaccination||Avoid mosquitoes by taking protective measures and receiving vaccination when appropriate|
|Dengue (especially risk of severe dengue)||Severe dengue occurs on repeat exposure to a different serotype of dengue; VFRs more likely to have had previous exposure||Avoid mosquitoes by taking protective measures|
|Abbreviations: VFR, visiting friends and relatives; PPD, tuberculin purified protein derivative; DEET, N,N -diethyl-m -toluamide.|
|1 Adapted from: Bacaner N, Stauffer W, Boulware DR, Walker PF, Keystone JS. Travel medicine considerations for North American immigrants visiting friends and relatives. JAMA. 2004;291(23):2856–64.|
|2 Hypothesis unless referenced to support assertions.|
|3 In animal models, DEET (liposomal preparations) prevents Schistosoma cercariae from penetrating the skin.|
Travel immunization recommendations and requirements for VFRs are the same as those for US-born travelers. It is crucial, however, to first try to establish whether the immigrant traveler has had routine immunizations (such as measles and tetanus) or has a history of specific diseases. Adult travelers, in the absence of documentation of immunizations, may be considered to be susceptible. Age-appropriate vaccinations (or serologic studies to check for antibody status) should be provided, with 2 caveats:
VFR travelers to endemic areas should not only be encouraged to take prophylactic medications but also should be reminded of the benefits of barrier methods of prevention, such as bed nets and insect repellents, particularly for children (see Chapter 2, Protection against Mosquitoes, Ticks, & Other Arthropods). VFRs should be advised that drugs such as chloroquine and pyrimethamine, as well as proguanil monotherapy, are no longer effective in most areas, especially in sub-Saharan Africa. These medications are often readily available and inexpensive in their home countries but are not efficacious.
VFRs should also be encouraged to purchase their medications before traveling to ensure good drug quality. Studies in Africa and Southeast Asia show that one-third to half of antimalarial drugs purchased locally are counterfeit or substandard.
The CDC-supported Heading Home Healthy program (www.HeadingHomeHealthy.org) is focused on reducing travel-related illnesses in VFR travelers. The program contains videos, informational resources, and health tools in multiple languages and was developed to assist not only VFR travelers but also their primary care health providers.
Jay S. Keystone