Travellers visiting friends and relatives: a high‐risk, under‐recognised group for imported infectious diseases

Over the past 10 years, net overseas migration has contributed to more than 50% of population growth in Australia.1 As of June 2016, an estimated 28.5% (6.9 million people) of the Australian population were born overseas.1 The top five countries of origin for these migrant groups were United Kingdom, New Zealand, China, India and the Philippines.1 There were 9.9 million short-term departures from Australia in the year ending December 2016,2 23.8% of whom were travellers visiting friends and relatives (VFR).2 VFR travel was cited as the second most common reason for travel behind ‘holiday’ (59.3%).2 India, China, Indonesia, Thailand, Singapore and Fiji were among the top 10 destination countries for short-term resident departures.2 A ‘classic’ VFR traveller is a migrant from a developing country (low income, usually a tropical country), residing in a developed country (higher income) and returning home to visit friends and relatives.3, 4 The term VFR traveller includes spouses, children born in the country of residence (second generation), students and refugees.3, 4 This term was adopted from the travel industry by the travel medicine specialty.3 It has been suggested that the purpose of travel (VFR) contributes to the high risk as opposed to ethnicity and visa status.3 VFR travel is associated with increased risk of acquisition of travel-associated illnesses, particularly with acquisition of infections, including vaccine preventable infections such as hepatitis A5 and typhoid 6, vector-borne diseases such as malaria,7 respiratory tract infections such as influenza, intestinal parasitic infections such as strongyloides and giardia, traveller's diarrhoea, resistant gram-negative infections8 and infections associated with risk behaviour such as sexually transmitted infections.9 Particularly vulnerable among these travellers are the elderly, paediatric, pregnant and immune compromised VFR travellers.5, 10 The risk faced by VFR travellers is often linked to the reasons for travel to the country of origin. Many travel to visit extended family in remote areas, to introduce new family members, to find a partner, attend functions, marriages, and funerals or to care for sick relatives or manage finances or property settlements.11 They also tend to have prolonged stays, live rurally in homes of friends and family and consume local food and beverage and come in contact with local animals or poor sanitation.11, 12 They are more likely to make last minute travel plans, travel when pregnant and with young children or have pre-existing chronic medical conditions such as renal impairment, organ transplant, human immunodeficiency virus (HIV) or immunosuppressive treatments which further increases the risk.11, 12 Additionally, VFR travellers may not have completed childhood vaccinations if born overseas,4, 13 and are less likely to have sought pre-travel advice, have travel health insurance or adhere to malaria chemoprophylaxis.13 Moreover, partial immunity acquired while residing in their country of origin to certain gastrointestinal pathogens, typhoid14 and malaria,13 will wane over time and VFR travellers may not be aware of this waning immunity. Above scenarios provide insight into how risk is perceived and how immunity is assumed as the person may have lived several years in the country of birth without suffering from the disease. Scenarios 4 and 5 highlight the challenges to travellers who travel while immune-compromised or have a chronic medical condition, and importance of weighing risks versus benefits of travel. In Scenario 5, the traveller decides to extend his stay at the last minute, fails to recognise the dangers of ceasing ART and decides to trial local alternative medications. Scenario 6 is of particular concern and awareness of risk of acquiring resistant infections, especially if hospitalised overseas, is an important part of pre-travel education. Several barriers exist in seeking timely travel advice. VFR travellers encompass a vastly heterogeneous population from a variety of different cultures with varying beliefs and attitudes to health. This cultural diversity seems to confer some of the biggest challenges in accessing travel health-related services, including language barriers, religious beliefs, false perception of immunity, reduced perception of risk, difficulty in accessing healthcare, lack of faith in the healthcare system and financial constraints.4, 11, 15 A detailed travel history and an updated immunisation history are essential, as VFR travellers may not have received all routine childhood vaccinations.11 In case of imminent travel, healthcare workers will need to be cognizant of shortened vaccination schedules.16 Annual influenza vaccination and tetanus boosters may also need to be updated prior to travel even in those who have completed all recommended childhood vaccines. Immunity against measles is of particular importance as imported cases occur in returning travellers.17 If there are concerns the traveller has not received his/her primary vaccination (two doses), we recommend checking measles, mumps and rubella serology prior to departure. In women of childbearing age, establishing immunity to rubella is important and should be confirmed. Further details on routine and travel-related vaccination and catch-up schedules employed in Australia can be accessed online through the Australian immunisation handbook website.18 Primary healthcare professionals are a valuable resource in opportunistically engaging potential VFR travellers during routine health consultations.19 A recent Australian study showed that general practitioners (GP) who see migrants had an increased understanding of VFR travellers as a high-risk population; however, GP who consulted in ‘languages other than English’ were less likely to perceive the increased risks.20 Raising awareness among multilingual GP from the same ethnic background can play a particularly important role in engaging and educating VFR travellers.16 Awareness of the risk these travellers face should prompt the healthcare provider to obtain a history of any intended future travel and update records on past travel history and illness. This opportunistic encounter can be used to assess risks, and educate, vaccinate or refer to specialist travel clinics as needed. Such an encounter may arise when potential VFR visit their GP for a routine consultation and mention an impending travel plan (e.g. in the context of requiring an extra prescription for routine medications). Some select groups may particularly benefit from referral to specialist clinics. These include paediatric VFR travellers, older VFR travellers with complex medical co-morbidities and immune-compromised VFR travellers. Prioritisation of recommended interventions based on the itinerary might be needed to help overcome financial constraints. The importance of seeking post-travel medical care in case of illness either during travel or on return should also be emphasised.15 Use of interpreters, awareness and acknowledgement of cultural sensitivities by primary healthcare professionals are important. Targeted community-based interventions have been tried to educate potential VFR travellers by distributing linguistically appropriate educational material on travel health during religious or cultural festivals. Multilingual information leaflets and posters in waiting rooms, ethnic grocery stores, travel agencies and other places frequented by ethnic communities might be useful in improving VFR community awareness on travel health,20 as may media articles in ethnic newsletters which highlight risks, risky behaviour, immunisation schedules and travel health clinic contact details. However, the effectiveness of this intervention has not been studied and determining the impact is difficult.21 There is an opportunity for local health services to evaluate their current services and maximise the potential to engage their VFR travellers. Expansion and improvement of travel health education and services for this vulnerable group are needed, as is access to affordable travel vaccinations. Involvement of local and national governments to improve policies on refugee and migrant health and education, catch-up vaccinations and reducing cost of travel vaccines to high-risk groups may also help increase access and utilisation of these services. Funding for prospective studies should be encouraged to quantify further the risk to VFR travellers, establish their baseline vaccination status, evaluate vaccination programmes and understand barriers to vaccination and pre-travel consultation. These studies will help direct implementation of catch-up vaccinations, targeted health education and reduce the burden of imported infectious diseases to both the individual and the community.