This is How Health Travels

[This article has been originally published in Catalan in 'Espai Salut' newsletter of Diputació de Barcelona]

When you are making a trip, your preparations should include obtaining accurate health information about the country you plan to visit (including both risks and precautions). Likewise, on your return you should, if necessary, seek specialised medical care.

When we think about great technological advances, what comes to mind are milestones like the printing press, telephony, computers and airplanes. More than a century after the first airplane flight in history, air travel to distant places has now become an everyday occurrence. In fact, the World Tourism Organisation (UNWTO) estimates that 1.4 billion international trips were made by tourists in 2018, an increase of 6% over the same figure in 2017 and the second highest number since 2010.

The World Tourism Organisation (UNWTO) estimates that 1.4 billion international trips were made by tourists in 2018, an increase of 6% over the same figure in 2017 and the second highest number since 2010

If we look at those data in greater detail, we see that the Middle East is the region where travel has increased the most (10%); the next largest increase has been in Africa (7%), followed by Asia, the Pacific and Europe (6%), and lastly America (3%). Every year more people are travelling to destinations all over the world, and long trips are becoming increasingly accessible to everyone.

An important aspect of planning any trip is to gather all the health information relevant to your destination, including essential vaccinations and, when necessary, prophylactic medications: for example, antimalarials when you are visiting a country where malaria is endemic. To do this, you should contact a specialised international health and travel clinic and make an appointment for a personalised consultation before you travel.

You should contact a specialised international health and travel clinic and make an appointment for a personalised consultation before you travel

During a pre-trip consultation, the medical professional will record relevant information about the traveller and the proposed itinerary to facilitate a personalised assessment of the specific risks involved. On the basis of this assessment, they will then recommend the best vaccination schedule as well as, if necessary, malaria prophylaxis and advise the traveller on how to travel safely and how to prepare the most complete travel medicine kit before they leave.

Today’s travellers also have the option of downloading mobile applications, such as TripDoctor, that enable us to travel with our own pocket doctor.

Even so, given the ever present risk of contracting a disease when travelling, it is very important not to let your guard down during the trip or after you get home. Travellers should bear in mind that the symptoms of some tropical diseases only appear after a long incubation period. Therefore, if you feel unwell or experience fever, dizziness or vomiting after a trip, you should see your doctor and mention where you have been on your travels. Travellers can also avail of another service, called a post-travel (or post-exposure) consultation, which is a check-up carried out by a professional specialised in tropical medicine on returning travellers and migrants from tropical or subtropical areas who present some kind of trip-related symptom.

We know that around 10% of travellers who visit a health centre before a trip also seek medical attention after their return. There are a great number of reasons for these consultations, but the three most common are diarrhoea, fever and skin lesions. Of these, fever is the most important as it accounts for 28% of post-trip consultations and is a symptom of a number of different diseases. There are many causes for fever in travellers and they include diseases that are potentially lethal if left untreated (such as malaria). Therefore, it is vitally important in such cases to seek specialised medical care.

There are a great number of reasons for these consultations, but the three most common are diarrhoea, fever and skin lesions. Of these, fever is the most important as it accounts for 28% of post-trip consultations and is a symptom of a number of different diseases

In today’s globalised world, we are now facing new risks, including the so-called emerging and re-emerging diseases. Every day we hear more about these diseases, but what does it really mean to say a disease is emerging or re-emerging? The term emerging diseases covers a variety of situations, including entirely new diseases as well as known diseases appearing for the first time in areas not previously affected and existing diseases presenting hitherto unknown manifestations. Re-emerging diseases, on the other hand, are diseases that are already known or controlled but which reappear, such as may be the case of measles in the United States.

In recent years, many regions of the world have been affected by outbreaks or epidemics of viral diseases transmitted by mosquitoes, which are called arboviral diseases (a name derived from the term arthropod-borne viruses). Arboviral diseases include dengue, zika and chikungunya. These outbreaks have not only affected countries where such diseases are endemic, for example the Zika outbreak in South America between 2015 and 2016, they have also spread to Europe, where no cases of autochthonous transmission had been recorded in 55 years in Europe. The first cases of local transmission of the dengue virus occurred in France and Spain in 2018, (six reported cases). These followed earlier outbreaks of chikungunya in France and Italy.

In recent years, many regions of the world have been affected by outbreaks or epidemics of viral diseases transmitted by mosquitoes, which are called arboviral diseases

The existence of cases of these diseases in returning travellers and the presence in Spain of the tiger mosquito (Aedes albopictus), a vector capable of transmitting arboviruses, has made this country a risk zone for the introduction and autochthonous transmission of arboviral diseases.

Tiger mosquito (Aedes albopictus)

In Catalonia, for example, 700 cases of arboviral disease have been confirmed in people returning from risk areas: 371 cases of dengue, 183 of zika and 146 of chikungunya. Last November, the Catalan Public Health Agency reported the first recorded case of autochthonous dengue in a person living in the Barcelonès Nord district, who had not travelled to any risk area.

In this context, it is vital to have surveillance systems designed to rapidly detect new cases and prevent autochthonous transmission. The protocol for the surveillance and control of viruses transmitted by mosquitoes in Catalonia specifies close surveillance of all cases of arboviral disease in humans and monitoring and control of mosquito populations.

It is vital to have surveillance systems designed to rapidly detect new cases and prevent autochthonous transmission

For example, when a case of arboviral disease is confirmed, the Public Health Service of the Diputación de Barcelona (the Provincial authority) provides support for an entomological inspection of the municipal areas in the province of Barcelona (all except Barcelona city) under an agreement with the Baix Llobregat Mosquito Control Service. So, the first step in the surveillance of these diseases is diagnosis, and diagnosis only happens when a person who feels ill following a trip abroad goes their health care centre and tells their doctor where they have been travelling.