The Visiting Friends or Relatives Traveler in the 21st Century: Time for a New Definition

Elizabeth D. Barnett MD, Douglas W. MacPherson MD, MSc(CTM), FRCPC, William M. Stauffer MD, Louis Loutan MD, Christoph F. Hatz MD, Alberto Matteelli MD, Ron H. Behrens MD
DOI: http://dx.doi.org/10.1111/j.1708-8305.2010.00411.x 163-170 First published online: 1 May 2010

Abstract

Background. Travelers visiting friends or relatives (VFR travelers) are a group identified with an increased risk of travel‐related illness. Changes in global mobility, travel patterns, and inter‐regional travel led to reappraisal of the classic definition of the term VFR.

Methods. The peer‐reviewed literature was accessed through electronic searchable sites (PubMed/Medline, ProMED, GeoSentinel, TropNetEurop, Eurosurveillance) using standard search strategies for the literature related to visiting friends/relatives, determinants of health, and travel. We reviewed the historic and current use of the definition of VFR traveler in the context of changes in population dynamics and mobility.

Results. The term “VFR” is used in different ways in the literature making it difficult to assess and compare clinical and research findings. The classic definition of VFR is no longer adequate in light of an increasingly dynamic and mobile world population.

Conclusions. We propose broadening the definition of VFR travelers to include those whose primary purpose of travel is to visit friends or relatives and for whom there is a gradient of epidemiologic risk between home and destination, regardless of race, ethnicity, or administrative/legal status (eg, immigrant). The evolution and application of this proposed definition and an approach to risk assessment for VFR travelers are discussed.

A primary goal of pretravel consultation is assessment of risk of travel‐related illness or injury to provide individualized advice about reducing these risks. Purpose of travel has emerged as one key factor influencing health risk during travel. Over the past decade, a specific group of travelers, those intending to visit friends or relatives (VFR travelers), has been identified with increased risk of travel‐related morbidity.

Several publications have focused on VFR travelers, addressing risk assessment, health disparities, barriers to care, and general travel medicine considerations.14 Subsequent studies have assessed specific travel‐related illnesses in VFR travelers. Fenner et al.5 found VFR travelers to be at increased risk of malaria, viral hepatitis, human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) and sexually transmitted infections compared with tourists and business travelers to the same destination.5 A review of travelers seen at GeoSentinel sites (a global surveillance network devoted to examining travel‐related health problems)6 found a greater proportion of serious and potentially preventable travel‐related illness in travelers who were identified as “immigrants” and selected “visiting friends or relatives” as their main purpose of travel compared with “nonimmigrants” whose purpose of travel was to visit friends or relatives. The authors of this study commented on lack of a standard definition for VFR travelers.7 Lack of a standard definition for VFR travel in the existing literature makes it difficult to compare data and to generalize advice about travel‐related health risks and recommendations from one group of VFR travelers to another.

The purpose of this article was to address the development and evolution of the concept of VFR travel by reviewing how the term “VFR traveler” has been used in the past, to discuss why existing definitions may no longer meet the needs of a changing population of travelers, and to propose a definition of VFR traveler that reflects the current state of population dynamics and global travel and incorporates modern concepts of risk assessment and management. How this framework can be used by clinicians in a pretravel encounter, by public health officials in developing policies and programs focused on reducing travel‐related health risks, and by researchers in developing a research agenda for VFR travel that would inform the clinical and public health practice of travel medicine will be discussed.

Methods

The peer‐reviewed literature was accessed through electronic searchable sites such as PubMed/Medline, ProMED, GeoSentinel, TropNetEurop, Eurosurveillance, using standard search strategies for the literature related to visiting friends/relatives, determinants of health, and travel. In addition, public access reports from international and national organizations and agencies were accessed for information on VFR migrants and health. Organizations and agencies included: The World Health Organization, Centers for Disease Control and Prevention (Atlanta, USA), European Centers for Disease Control and Prevention, the Health Protection Agency (UK), and others. An expert panel, convened with the support of the International Society for Travel Medicine, reviewed all results and participated in the preparation of this report. As this report involved no contact with patients or individuals or personal medical information, research ethics approval was not sought.

Evolution of the Term “VFR Travel”

Travel for the purpose of visiting friends or relatives (VFR travel) is a concept first defined by the travel and tourism industry and included travelers whose main purpose of travel was family‐related, and were therefore distinct from tourist, business, or long‐term travelers such as missionaries or other volunteers. The term was used in reference to both domestic and international travel for the purpose of gathering economic data about different types of travelers and did not have specific health connotations.8,9 Travel industry research focused on the relationship between VFR travelers and potential economic impact and opportunities in tourism markets.10 Travel medicine experts noted that they were observing a traveler who appeared to be at higher risk for morbidity and mortality and was distinct from more traditional travelers such as tourists, students, backpackers, or business travelers. The travel medicine field adopted the term VFR and applied it to this population of travelers. A number of assumptions were made when using the term VFR traveler in the health context.11 The “classic” VFR traveler criteria typically included: ethnicity of the traveler different from the host country population but similar to the destination population, intended purpose of travel to visit friends or relatives, and the destination representing a higher prevalence risk of specific tropical infectious diseases (eg, malaria).

A typical VFR traveler could be described as follows: A 30‐year‐old Nigerian man who immigrated to the United States at age 20 traveling to Nigeria to visit his parents in the village where he had been born and raised. This scenario captures the characteristics felt to be central to the “classic” definition of a VFR: an immigrant returning to his country of origin for a visit with friends or relatives who is racially or ethnically distinct from the majority population in his adopted country, moving from a higher income country with low tropical disease prevalence to a lower income country with higher risk of these diseases, and who is also experiencing living conditions more similar to the local population than that of a typical tourist or business traveler. The shortfall in the use of the classic definition of VFR traveler in an increasingly mobile world is that the underlying assumptions of what constitutes a VFR traveler no longer apply to a large number of travelers who may have risks of travel‐related illness which are similar to those experienced by the classic VFR traveler. What may have been a useful framework in the past may no longer apply to 21st century patterns of global travel and population mobility. An early indication of the inadequacy of this definition was the introduction of qualifiers to the term VFR. “Immigrant VFR” was introduced to distinguish the foreign‐born traveler from the child or non‐foreign‐born spouse of this immigrant traveler (“traveler VFR”), though both might travel to the same destination with the purpose of visiting friends or relatives.7 Other authors chose terms such as immigrant traveler, migrant traveler, ethnic traveler, and semi‐immune traveler. It became apparent that the increased number of terms and the different ways in which they were applied was leading to increasing difficulty in drawing conclusions or developing recommendations that could be applied to the population of “VFR travelers.”12

Changing Patterns of Population Mobility

Changing global travel and migration patterns have provided additional impetus for reappraisal of the term VFR traveler. International tourist arrivals have increased from 150 million in 1970 to 900 million in 2007 and are expected to reach 1.6 billion by 2020.13 More than half (an increase of 400 million arrivals) of this increase occurred in the 13 years since 1994, when the term VFR was used first by the travel industry (compared with the increase of 350 million arrivals in the previous 24 years between 1970 and 1994). Although travel arrivals to Europe remain highest in magnitude, travel to East Asia and the Pacific, South Asia, the Middle East, and Africa will experience the greatest rate of growth, with lower rates of growth being seen for arrivals to Europe and the Americas. Other changes in global mobility patterns include increased urbanization, leading to disparities in health risks between rural and urban areas of the same country or region, and increased intra‐regional migration, such as within Asia between countries with similar socioeconomic status but variation in other epidemiologic health risks.14

Changes in global migration patterns and infectious disease epidemiology present challenges to the classic definition of VFR in the following ways: travel to some destinations may not be associated with the magnitude of increased risk of tropical diseases that has been present in the past (eg, decreased rates of malaria transmission in central urban areas of sub‐Saharan Africa15,16); noninfectious risks of travel are being recognized and described in more detail (eg, trauma, road accidents, and air quality)17–19; individuals with remote connections to their country/region of birth (second‐ or third‐generation immigrants) may be returning to explore their roots, staying with distant relatives; spouses, and children, not originally from the destination, may be accompanying a “classic” VFR traveler to his/her home; immigrants may travel for primary reasons other than visiting friends or relatives; and racial/ethnic distinction alone is not a sufficient factor on which to base increased health risk during travel (eg, leading to expressions of implicit bias and stereotyping by clinicians, researchers, and policy makers).

Several scenarios can be envisioned that highlight the challenges of VFR definition in the current era. These include:

  1. A 23‐year‐old Canadian‐born white woman travels to India to be married to her Canadian‐born fiancé who is of Indian descent.

  2. A 40‐year‐old man who works in the mines in South Africa returns to rural Botswana to spend the holidays with his family.

  3. A 45‐year‐old businessman based in Singapore travels to Dubai to visit his family but will stay in a hotel as he will be conducting business while there.

  4. An 18‐year‐old US‐born male of Vietnamese descent travels to Hanoi to visit distant relatives; he will get around the city on a motorbike.

  5. An 8‐year‐old UK‐born Nigerian boy travels to Nigeria to go to boarding school in a town where he has no relatives or family friends.

In each of these scenarios, application of the “classic” VFR definition may not capture the complexity of travel‐related health risks for the individual traveler. A revised framework and definition of VFR travel that can embrace changes in global migration patterns, the increased variation in purpose of travel, and assessment of changing and variable epidemiologic travel health risks, is required. We therefore propose a revised definition of VFR travel with two components:

  1. the intended purpose of travel is to visit friends or relatives; and

  2. there is an epidemiologic gradient of health risk between the two locations supported by an assessment of health determinants.

Redefining “VFR” Travel

The intent to visit friends or relatives at the travel destination is fundamental to the new framework. Connection with the local population is related to multiple aspects of the travel experience such as duration of travel, type of accommodation, mode of travel at the destination, exposure to food and water, intimate exposures, and access to social support systems including health care. These factors affect health of travelers to different magnitudes, and are listed in Table 1. Focusing on the primary goal of travel (visiting friends or relatives) rather than on characteristics of the traveler (ethnicity or immigration status) provides a more useful foundation for travel consultation based on assessment of individual travel‐related health risks.

View this table:
Table 1

Factors that may influence the health of travelers (by strength of evidence)

Strength of evidence—strongStrength of evidence—weaker, conflicting, or unknown
• Age, especially extremes of age32• Sex/gender
• Health status/underlying medical conditions3335• Access to pretravel advice
• Access to safe food, clean water, sanitary conditions36• Country of birth/migration history
• Destination (infectious disease risks, extremes of climate, environmental risks such as high altitude, air pollution)• Recreational exposure to bodies of fresh water or ocean
• Intent to seek medical care during travel
• Duration of travel (for some risks)37• Intent to travel to large gatherings (Hajj, Olympics, etc.)
• Mode of travel (air, sea, land; self‐drive, motorcycles)• Intent to attend school
• Adherence to pretravel advice, immunizations, and medications• Need for last minute travel
• Intent to engage in adventurous activities (rock climbing, parasailing, scuba diving)• Intent to engage in higher risk activities (eg, sexual, illegal, drug use)
• Health beliefs/risk perception/perceptions of control over health outcomes• Exposure to animals (rabies/dogs, avian flu/birds, hepatitis E/pigs)
  • Strong evidence = observational studies or stronger research design that includes comparative group of nontravelers or population data of comparative outcomes; weaker evidence = observational studies without comparative analysis.

The second part of the definition is the requirement for an epidemiological health risk gradient between home and destination. Classically, this has referred to increased risk for vector‐borne diseases (malaria, dengue, Japanese encephalitis, and chikungunya) or vaccine preventable diseases (hepatitis A, typhoid). The new framework encourages a broader view of health risks to include noninfectious risks such as accidents or injury,20 air pollution, varying accommodations, extremes of climate, and high altitude. As travel patterns change, and there is more travel within regions and from known higher risk areas to lower risk ones, concepts must be broadened to include specific ways in which the risk gradient affects the traveler. For example, travelers from the Western parts of the United States to the Eastern United States may benefit from information about prevention of Lyme disease, travelers between the UK or Australia to the Americas and Europe might reduce their risk of road traffic accidents with some orientation to opposite side of the road driving, and residents of relatively crime free areas may benefit from counseling to avoid petty or violent crime when visiting large urban areas with increased crime. Conversely, the risk gradient may include travel from high‐ to low‐risk destinations for some health outcomes. For example, previous exposure to and therefore development of immunity to hepatitis A may decrease the risk of this disease to the VFR traveler. The link between the purpose of travel and risk gradients may work well in differentiating between travel‐related health risks of VFR travelers and those who travel for business, tourism, education, or employment, but it remains to be seen how well it will identify differences in outcomes for other purposes of travel, such as backpacking or humanitarian workers, and to what extent this is overlapping.

This proposed definition of a VFR traveler omits several of the characteristics that have been included in the previous definition. Specifically, it is not necessary to be an “immigrant” in the departure country to be a VFR traveler. The term “immigrant” has legal connotations as do other terms such as “refugee,”“alien,”“migrant,” and these administrative terms are used variably from country to country and even regionally within countries. An administrative or legal classification, when taken out of context, may have limited application to health determinants and risk of travel‐related health risks. Using administrative or legal class to predict health risk can lead to stereotyping and implicit assumptions about the patient/subjects/populations by the health care provider, researcher, or policy maker. These inaccurate assumptions about patients/subjects/populations may lead to provision of inappropriate clinical care and advice, introduce bias into study designs, and/or lead to inaccurately aimed public health interventions.

Children or spouses of foreign‐born individuals may face specific enhanced travel‐related health risks when they visit friends or relatives in a parent's or spouse's country of birth, and those who travel to visit friends or relatives may experience different health risks during travel than those risks which other types of travelers would experience in the same destination. The requirement to be an “immigrant,” or immigrant's child, has therefore been omitted from this framework. In addition, there is no ethnicity component; the traveler does not need to be ethnically distinct from the majority population of the departure country to be considered a VFR traveler. The movement away from this requirement refocuses the emphasis on assessment of travel‐related health risk rather than on characteristics of the traveler that may not be relevant to the specific risks he or she may face.

Removal of race or ethnicity from the definition of VFR is intended to bring scientific rigor to travel risk assessment. Race and ethnicity, when and where relevant to travel risk assessment, are more directly captured within the proposed VFR definition based on the intent of travel and the determinants of health. Both race and ethnicity are inter‐dependent variables within the broader concepts of socioeconomics, genetics and biology, behavior, and environmental assessment. Equally, immigrant status is an administrative classification that changes over time and varies by place and is not a direct or stable factor in assessing risk. There is a tendency in the literature for clinicians, researchers, and policy makers to assume “we all know who we are talking about” when using the term “immigrant.” This leads to poor scientific assumptions and conclusions that, in the end, limit generalization or comparison of populations (eg, is the “immigrant” population seen by my clinic the same as the one described in this article?). The change in the VFR definition is to address the limitations posed by confining the term VFR traveler only to travelers who are immigrants or who are ethnically distinct from the local population. We hope the new, more general definition, will encourage clinicians, researchers, and policy makers to define the population they are addressing in their methods, increasing the understanding of risk in specific populations and refining the literature. Furthermore, we hope the more general definition will encourage focusing on the determinants of health of individuals and populations and will decrease stereotyping and implicit bias currently evident in clinical practice and the literature.

Determinants of Health and the VFR Traveler

Independent of the reason for travel, the epidemiological risk is another important determinant of health that contributes to travel‐related morbidity. These risks should be taken into account during every travel consultation and are not unique to VFR travelers (Table 2). The determinants of health that are also relevant to the travel health assessment include: socioeconomic factors (of the individual as well as the destination country); genetics/biology (variable susceptibility to disease such as preexisting malaria immunity; presence of glucose‐6‐phosphatase deficiency [G6PD]); behavioral characteristics of the traveler and the destination population (perception of control over one's destiny, risk‐accepting/taking behaviors, health beliefs); and environmental factors (public safety and security, housing, exposure to extremes of climate). Some of these factors have been validated as clearly associated with increased risk, whereas others are less well defined, and may carry various weights for different travelers.

View this table:
Table 2

Health determinants affecting risk of morbidity in travelers

Determinant of HealthIndividualSocietal
Socioeconomic statusAnnual income (individual or family)Gross national and domestic product
Highest level in schoolingEducational attainments
Language literacyLiteracy levels
Single or dual parent familyFemale employment rates
Fecundity rates
Maternal‐child mortality rates
Immunization coverage rates
Genetics/biologyInnate or acquired immunityPopulation diversity
Hemoglobin S trait and malariaLife expectancy at birth
Previous hepatitis A infection
Population‐based disability adjusted life years (trauma, chronic disease)
BehaviorRisk acceptance/takingSmoking rates
SmokingAcceptance of immunizations
Diet and exerciseSocietal and cultural norms
EnvironmentHome ownershipSocial infrastructure for education, transportation, housing, food, and water
Toxins exposures, domestic, occupationalPublicly funded social programs for economically disadvantaged
Water, food, and air quality disease ratesSocietal political stability, safety and security
Extreme weather or environmental events (heat, cold, drought; storms; seismic events; floods, mud slides, etc.)

Assessment of epidemiologic risk gradients and integration of the determinants of health into the pretravel consultation involve obtaining detailed information from the traveler and as such are integral to the work of the travel medicine provider. The new definition for VFR traveler represents an accommodation to increasing diversity in the types of travelers and to changing patterns of global travel. In fact, this approach represents a shift to a more clinically relevant paradigm where risk assessment for travel‐related morbidity is accomplished for all travelers based solely on assessment of epidemiologic risk and evaluation of these risks based on the determinants of health described, rather than by using types of traveler as proxies for differing types of risk to be experienced. One might argue that the definition is so broad as to eliminate the ability to distinguish subgroups that are at significantly increased risk and therefore warrant specific interventions. The elimination of the requirement to be an immigrant or to be ethnically distinct from the local population may blur the distinction between groups of VFR travelers, such as identified by the GeoSentinel network in defining “immigrant” and “traveler” VFRs. At this time, the identification of the purpose of travel continues to provide useful information for the travel medicine professional. Individual clinicians, researchers, and policy makers may still be addressing subpopulations but rather than assuming all “immigrants” or ethnically based populations are the same, we hope the broader definition will encourage more precise language in defining these subpopulations, creating more equitable, comparable, and scientifically sound data and recommendations. The following sections outline ways in which the new definition for VFR travel can be used today by clinicians, public health officials, and researchers.

This approach to travel risk assessment will place greater onus on the practitioner, public health official, and researcher. Standardizing an approach to clinical risk assessment based on incomplete or inexact knowledge of risk will highlight areas of uncertainty that are inherent in travel. Critical decision‐making in the face of uncertainty will also mean greater engagement of the traveler in deciding how to manage his or her own risks (and may decrease expression of implicit bias by providers). Similarly, public health officials will be pressed to apply more rigorous science in policy deliberations and program design related to travel health risk management. The highest expectations in applying a stable and robust VFR definition may be on the travel health researcher in creating quality study design and evaluations that can be generalized and applied in the real world setting of clinical and public health practice. But having recognized these challenges for practitioners, public health, and researchers, the greatest challenge in the new definition may well be the empowerment for the VFR traveler and their acceptance of a role in managing the uncertainty related to future events occurring during travel.

Application of These Concepts by Travel Medicine Professionals, Public Health Officials, and Researchers

Clinicians

Pretravel assessment of VFR travelers can be enhanced by addressing specific topics within the domains of the determinants of health listed in Table 2. Clinicians can use this approach to identify specific gradients of risk for VFR travelers in multiple areas in addition to infectious diseases. A more nuanced approach is also possible for travelers who may appear very different but in fact have quite similar risk profiles, or who appear similar but in fact may have quite different risks.

Risk assessment within these additional domains also encourages increased attention to factors and outcomes other than infectious diseases, such as road traffic accidents, air pollution, personal safety, psychological and psychosocial issues, and exposures to extremes of climate or severe weather events. This framework for risk assessment can also be applied to urban‐rural migration within a country (such as moving from an urban area of Brazil into a yellow fever endemic area, or moving, in many countries, from a relatively safe rural area into a large urban area with risks of urban violence, poorer sanitation, and air pollution). As inter‐regional travel increases and classic travel risks move away from infectious disease risks to a broader concept of travel‐related health problems,21 it will be necessary to explore in more depth the risk gradient for VFR travelers in these different domains.

Application of this framework for VFR travelers will be new to many clinicians, though most travel medicine practitioners are already familiar with the process of risk assessment that is used in the routine practice of travel medicine. To facilitate use of the new definition specific to VFR travelers, case scenarios have been developed that illustrate application of the definition.22 These cases will assist clinicians in understanding the difficulties incurred when using legal status or ethnicity to determine risk. Over time, this framework should facilitate design of studies involving VFR travelers.

Public Health Officials

Global security and migration‐related illness are topics of increasing international importance.23,24 Acknowledging the increased role of VFR travel and potential for transmission of infectious diseases has been seen with respect to influenza, HIV infection, tuberculosis, hepatitis A, dengue, chikungunya, malaria, and other infectious diseases.25,26 Noninfectious causes of morbidity may include exposure to counterfeit or adulterated medications,27,28 contaminated or poisonous foods (melamine‐contaminated dairy products), accidents, physical or sexual violence, and exposure to air pollution or high altitude. Examples of public health initiatives to address potentially travel‐related noninfectious disease issues include “Look Right” signs in the UK and education and efforts to improve air quality around the time of the Beijing 2008 Olympics. Other public health interventions at local levels that attempt to address VFR travel risks include thermo‐screening upon departure at airports,29,30 and health screening of returned domestic servants in Singapore.31

Researchers

It is particularly important to define terms and frames of reference that will allow formulation of research questions and robust study design. The revised definition can be used consistently with the study designer determining whether they wish to use even more specific inclusion and exclusion criteria that ultimately will determine the comparability and generalizability of the study populations. This will also allow testing of previous assumptions about VFR travelers and exploring relative importance of specific aspects of risk (length of time out of country, local versus hotel accommodation/food, health beliefs, risk of blood or body fluid exposure, access to care). This will be invaluable in providing quality data to guide the clinical encounter and to inform public health policy and program design and implementation that ensures that an evidence‐based approach to clinical and public services is available to practitioners and travelers.

A strong recommendation is made for the adoption, implementation, and evaluation of the proposed definition by the travel medicine community, including clinicians, researchers, and public health officials. The requirements for surveillance and research that addresses the risk of travel‐related illness in different groups of travelers, such the studies done by the GeoSentinel Network and TropNetEurop, will be aided by a more standard definition of VFR traveler. Within the framework of the definition, addressing the health risks in subgroups of VFR travelers, such as children of immigrants who are visiting their parents' country for the first time, business travelers who are also visiting friends or relatives, and individuals spending time staying with local families can then be examined.

Conclusions

Changes in global migration patterns and population demographics have prompted reappraisal of the concept of the VFR traveler. Some components of the classic definition no longer serve the purpose of defining a distinct group of travelers with enhanced risks of adverse health outcomes directly related to their travel. An approach to VFR travel focusing on intent of travel being to visit friends or relatives, and a gradient of epidemiological health risks between the home and travel destination is proposed. Evaluation of health risk based on individual and population determinants of health characteristic provides both a current and dynamic view of risk management.

Clinicians are encouraged to identify those who travel for the expressed intent of visiting friends or relatives as being a group for which a defined framework for risk assessment can be applied. This requires an evaluation of the health determinants as an indicator of risk related to travel. Public health officials will find this construct helpful in informing policies and designing and implementing programs to reduce travel‐related health problems on a population basis. Researchers in travel health will benefit from use of a standardized population‐based framework for research design and implementation. Using defined and comparable population‐based health determinants, researchers can study specific disease risks and outcomes relevant to the health of VFR travelers.

There is certainly a requirement to validate this framework. An integrated approach between clinicians, public health officials, and researchers to test these hypotheses and provide data‐driven recommendations for prevention of travel‐related illness in well‐defined groups of VFR travelers will be instrumental in advancing the field of travel medicine.

Acknowledgments

The authors acknowledge with great appreciation Ms Brenda Bagwell (Administrative Director, ISTM) and the International Society of Travel Medicine who provided generous logistical, financial, and organizational support for working group meetings resulting in this article. Brian Gushulak and Rogelio Lopez‐Velez provided valuable input.

Disclaimer

The opinions expressed here are solely those of the authors and do not necessarily reflect the position of any government, agency, university, society, or other body to which they may be currently or in the past affiliated.

Declaration of Interests

R. H. B. received support from the UCLH/UCL Department of Health's NIHR Biomedical Research Centers funding scheme. The other authors state they have no conflicts of interest to declare.

References

View Abstract