Travel medicine

INTRODUCTION AND OVERVIEW

There has been an increasing trend for people to travel internationally.¹ Ease of air transportation has ensured that nearly 1 billion people travel internationally each year to every part of the globe.² These travellers are potentially exposed to infectious diseases for which they have no immunity, as well as other serious threats to wellbeing, such as accidents and exacerbation of pre-existing medical and dental conditions. Conservatively, it is estimated that 30–50% of travellers become ill or are injured while travelling.^3,⁴ Relative estimated monthly incidence rates of various health problems have been compiled elsewhere.³ The risk of severe injury is thought to be greater for people when travelling abroad.^1,⁵

In terms of morbidity, infectious diseases such as respiratory tract infection and traveller’s diarrhoea, and injuries, are important concerns for travellers.^1,^4,⁵ The main health complaints of returned travellers vary considerably, depending on the country visited and the duration of the visit. Some studies have reported, based on travel insurance claims, that respiratory, musculoskeletal, gastrointestinal, ear, nose and throat, and dental conditions were the most common presenting problems,⁶ whereas others have found that infectious disease (43.5%), accidents involving the extremities (15.3%), psychiatric conditions (8.2%), pulmonary disorders (4.7%) and accidents involving the head (4.7%) were the most common.^3,⁷ Fortunately, few travellers die abroad, and those who do tend to die of pre-existing conditions, such as myocardial infarction in travellers with known ischaemic heart disease. However, accidents are also a major cause of travel-related mortality.⁸ This chapter highlights some of the current issues in travel medicine, but excludes specific discussion concerning migrant health.

DEFINING TRAVEL MEDICINE

Travel medicine is a new multidisciplinary specialty area that has emerged in response to the growing needs of the travelling population worldwide. Nearly all general practitioners (GPs) will need a basic knowledge of travel medicine, some GPs will make it an area of special interest and there are medical specialists whose whole practice is travel medicine.

Travel medicine seeks to prevent illnesses and injuries occurring to travellers going abroad and manages problems arising in travellers coming back or coming from abroad. It is also concerned about the impact of tourism on health and advocates for improved health and safety services for tourists.^9a

The latter aspect recognises the impact of travel on ecosystems around the world, particularly the introduction and spread of diseases and disease resistance.

The roles of the GP or travel health adviser in the provision of travel health advice can be regarded as a continuum (Fig 45.1) and include:

• providing pre-travel assessment and advice, which may take place in a travel medicine clinic, during a standard general practice consultation, or through giving advice to other practitioners

• advising on other precautions that should be taken against diseases to which the person is likely to be exposed during travel

• immunising travellers for their protection

• immunising travellers to provide the relevant certificates to facilitate travel through epidemiological control posts at sea and air ports

• prescribing appropriate prophylactic and self-treatment medications

• advising on important safety nets for travellers abroad, including travel insurance and finding medical assistance abroad

• advising on follow-up of travellers returning from overseas

• managing medical problems of travellers from abroad, which may also involve aeromedical evacuation, emergency assistance and even ‘good Samaritan’ acts on board aircraft or abroad

• providing advice on health, including pre-existing problems while away

• informing public health authorities about travellers presenting with any possible notifiable disease.

FIGURE 45.1 Relationships in the continuum of travel medicine

PRE-TRAVEL HEALTH CONSULTATION

The pre-travel health consultation involves consideration of and advice about various aspects of travel-related health, including fitness to travel and the health risks of travelling in itself, including exposure to infectious diseases and diseases arising from travel. This may necessitate the provision of malaria and other chemoprophylaxis, and various vaccinations. The areas that may be covered in the pre-travel health consultation with travellers are listed in Table 45.1.

TABLE 45.1 Areas that might be covered in pre-travel preparation of patients going aboard

Advise/discuss
Insects	Repellents, nets, permethrin
Ingestions	Care with food and water
Infections	Skin, environment
Indiscretions	STIs, HIV
Injuries	Accident avoidance, safety
Immersion	Schistosomiasis
Insurance	Health and travel insurance
	Finding medical assistance abroad
	First aid advice
Vaccinate
Always	National immunisation schedule vaccines
Often	Hepatitis A, influenza
Sometimes	Typhoid
	Japanese encephalitis
	Meningococcal disease
	Polio
	Rabies
	Tetanus–diphtheria
	Yellow fever
Older travellers	Pneumococcus
	Influenza
	Pandemic influenza, e.g. pandemic (H1N1) 2009
Prescribe
Always	Regular medication
Sometimes	Antimalarial medication
	Diarrhoeal self-treatment
	Condoms
	Traveller’s medical kit

Source: modified from Seelan & Leggat 2003 ¹⁰ and Ingram & Ellis-Pegler 1996¹¹

Before the pre-travel consultation, a risk assessment needs to be undertaken, evaluating the risks of both the destination and the individual travelling there. Information on the exact itinerary and special medical problems of the traveller needs to be obtained early, up to 6–8 weeks before travel for most travellers, perhaps longer when travellers are going overseas for long-term employment, placement or holiday touring. In the clinic setting, it is preferable that this information is obtained well before the traveller presents for their first face-to-face consultation. It is necessary to establish:

• where they are travelling

• which areas of those countries they plan to go to

• what they plan to do in that country

• how they are going to get there

• at what time of year they are departing

• how long they will be travelling for.

This information may be obtained by a standardised questionnaire, which may be developed in the context of a travel clinic network or general practice network, or by individual travel health advisers. The World Health Organization (WHO) has provided an example of the types of questions to be asked in international travel and health.¹² Practice or clinic staff can assist by ensuring that this information is obtained before the formal consultation. It is important that the procedure is time efficient for a practice, to improve flow and time management.

In the general practice setting, detailed records may be available to assist in assessing the traveller’s medical risks for travel. In any event, these records may need updating if the traveller has not presented to the GP for some time. Travel clinics, general practices and those in the travel industry should make it clear to prospective travellers that they should present early before travel, to obtain their travel medicine advice, immunisations and chemoprophylaxis or be referred for specialist advice, such as a pre-travel dental check. This may be best stated in a formal practice policy, so that travellers are aware of these possible requirements, which might be advertised in clinic newsletters, websites or practice updates or reminders.

ESTABLISHING THE RISKS

The risks of travel that need to be assessed for most travellers include the risks of the:

• destination

• mode of travel

• traveller’s medical history

• intervention.

It is important in travel medicine to establish the risks of the destination and the mode of travel in terms of the hazards and the potential exposure to these hazards, and to examine the traveller’s medical history to establish host risks, which may affect selection and use of interventions in the pre-travel health consultation. These are then weighed against the risks of the intervention.

The risks of the destination and any specific requirements for travel health advice may be obtained from a variety of resources. The WHO publishes a booklet entitled International Travel and Health.¹² Several other publications and sources of information relevant to travel medicine are also available. Online computerised databases have long since been mooted as useful aids for providing the most up-to-date and validated information for advising on travel medicine.¹³

POST-TRAVEL CONSULTATION

The traveller should also be advised of the possible need for follow-up and management after travel, particularly if going to a high-risk area (e.g. for malaria) or if they have any illness upon return (e.g. fever; persistent or bloody, mucous diarrhoea).¹⁴ It must be impressed upon the traveller that, in the event of any illness upon return, they should inform the treating physician of their recent travel and that they have travelled, for example, to a malaria area. It is important, if seeing a traveller with a post-travel health problem, that a risk assessment similar to the pre-travel health consultation is undertaken, guided by the presenting features of the illness or injury against a background of the patient’s general health. Even travellers who have been seen in the clinic or general practice for pre-travel health advice may need to have the risk assessment re-evaluated if any of the parameters of risk have changed (e.g. the person has travelled to a new destination). The risks of travel may also be modified by:

• having travel insurance and access to an emergency assistance service

• post-travel screening and interventions

• malaria eradication

• empirical eradication treatment (e.g. deworming treatment).

The effective early management of post-travel health problems early can significantly reduce morbidity and mortality, among travellers, from diseases such as malaria, which may still occur post travel as no intervention is necessarily 100% protective. Managing the risk and these travel health problems in a timely manner can also reduce the risk to local populations from this disease, and post travel it may assist in reducing the risks to the traveller’s own community (e.g. in dengue recognition and management).

DEVELOPMENTS IN TRAVEL MEDICINE

Several key developments in the past two decades have ensured the continuing emergence of travel medicine as a specialty area. The development of national programs and guidelines in travel health was an important advance, as this recognised the need to develop a consensus strategy for combating commonly encountered infectious diseases and other problems encountered by travellers. Examples of these include the former Australian Government’s Travel Safe® Programme, including the publication of Australian guidelines for travel health,¹⁵ and the US Centers for Disease Control and Prevention (CDC) travel health program.¹⁶ These programs and guidelines were directed at the major providers of travel health advice, such as general practices and public health agencies, but also travel clinics and travel agents. Internationally, the World Health Organization has also been producing travel health guidelines. (Examples of major travel health guidelines can be found in the Resources list.)

Three main challenges confront effective travel medicine practice.

• Travellers must recognise the need for travel health advice before travelling abroad, particularly given that a recent airport survey suggested that only 50% of international travellers abroad had sought pre-travel health advice.¹⁷

• Travellers need to seek travel health advice in a timely manner, preferably 6–8 weeks before travel.

• Travellers should obtain travel health advice from a qualified source. In the survey previously mentioned, only one-third of travellers had sought pre-travel health advice from a healthcare professional.¹⁷

Many of these challenges can be at least partially addressed through industry and government cooperation, particularly at the level of the travel agent or airline, which have initial contact with travellers. Many countries now have foreign travel advisory services that help keep practitioners advised about things such as important travel warnings and global disease outbreaks.

One of the most important factors influencing whether travellers seek health advice is the perceived risk and severity of tropical diseases,¹ despite their relatively low health and safety risk to travellers compared with accidents and less exotic conditions such as traveller’s diarrhoea. In addition to the prevention of potentially lethal diseases and injuries among travellers abroad, the importance of providing travel health services is also increasingly being recognised in relation to early detection and reporting of imported infections.