More people are travelling abroad more than ever before. The number of easy to reach destinations is increasing year by year. Cheap flights and a more adventurous spirit have enabled many millions of people to see parts of the world that their parents and grandparents only dreamed about. UK residents took 54 million journeys abroad in 1998, with this number set to increase in years to come.

There has been a significant increase in trips to exotic locations over the last ten years, with people frequently visiting Africa, Asia, the Caribbean and Latin America for business and pleasure. As a result of more frequent foreign travel, people are at increased risk of infectious diseases such as malaria, viral hepatitis and typhoid fever.

50% of travellers experience diarrhoea while abroad¹, while others may be unfortunate to be involved in an accident or require medical or dental treatment, which itself may result in ill health and put the sufferer at the risk of infection from blood transfusion.

Why Do People Travel Abroad?

There are many different reasons for travelling abroad; here is a list of types of travellers:

• Short-stay travellers, including business travellers, politicians and airline crew

• Package holidaymakers

• Adventure or expedition tourists including backpackers and around the world travellers

• Expatriates including embassy and government employees, missionaries, aid-workers and business people

• Occupational travellers including healthcare workers, aid-workers, missionaries and military staff

• UK citizens returning to their native country

These groups of travellers are exposed to a variety of different health risks, depending upon the purpose of their travel, their destination and the activities that they undertake while abroad. The risk of ill health while travelling is not only due to problems that may occur at the final destination. People can become unwell on the outward journey, either because of a condition that they already have or because they develop an illness while travelling.

What Illnesses Do Travellers Get?

Travellers should be advised about the health risks that they may be exposed to while travelling abroad. These include:

• Infections, such as:
  • Malaria
  • Travellers' diarrhoea
  • Typhoid fever
  • Viral hepatitis
  • Sexually-transmitted diseases
• Environmental hazards, such as:
  • Extreme heat and cold
  • High altitude
• Accidents and violence, such as:
  • Car and motorcycle accidents
  • Wars and local violence
• Existing medical problems flaring up while abroad, such as:
  • Heart problems
  • Breathing problems
  • Deep vein thrombosis

By travelling abroad people expose themselves to hazards that they may never have previously come across at home. The likelihood of illness depends on many different factors, including the person's age and their general health, the place(s) being visited and the precautions they have taken before travelling.

As well as infections and illness because of existing medical problems, there are other ways people can get unwell while travelling. Some people get severe motion sickness or become stressed when travelling, especially if they have not travelled much before. Changes in climate may make people feel unwell, whether the climate is very hot or very cold, before becoming accustomed to a new environment. When travelling abroad on holiday individuals may exert themselves more than usual and often eat and drink more than they would do at home, both of these situations can lead to feeling unwell.

What Are the Common Reasons for Becoming Unwell When Abroad?

Travellers' Diarrhoea

There is a phrase: 'Travel broadens the mind and loosens the bowels'. Getting diarrhoea while travelling is a very common problem, especially when people visit developing countries. It affects about half of all travellers abroad². The water is often not as clean as it is at home and it frequently contains bacteria that can cause diarrhoea. Food hygiene is often at a standard below what we are used to and again bacteria from poorly cooked food, food that has been left un-refrigerated, or salad that has been washed in the local water, can all cause stomach upsets and diarrhoea.

Hepatitis A

Hepatitis A is a viral infection that is transmitted from person to person in contaminated water and food. This condition, common in developing countries, can lead to sickness and diarrhoea as well as jaundice (the skin and whites of the eyes turning yellow). In a few individuals, particularly the elderly, it can lead to death from liver failure. The risk of catching hepatitis A is higher in people travelling rough compared with those staying in hotels, and can be as high as one in 20 people³.

Sexually-transmitted Diseases

About one in ten travellers have casual sexual contact when they are abroad⁴. In one recent research study, two-thirds of people who had new sexual contacts while away did not use condoms. The highest incidence of sexually transmitted diseases is in 15 - 24 year olds but this is not the only group affected. Alcohol and drugs when abroad can cause relaxed behaviour and attitudes towards holiday romances. This has led to an increase in reported cases of sexually transmitted diseases following travel abroad. Sexually transmitted diseases caught by travellers include gonorrhoea, syphilis, hepatitis B and C and HIV infection. Travellers are encouraged to practice safe sex and to take condoms with them on their travels. In addition, the fashion for acupuncture, tattooing and body piercing, particularly in developing countries, carries with it a high risk for the transmission of hepatitis B and other blood-borne infections such as HIV.

Typhoid

Typhoid fever is another illness that is caught from contaminated water or food. People with typhoid fever develop diarrhoea, a high fever and sometimes a spotty skin rash (called rose spots). If left untreated, typhoid can lead to death in one in ten people. Fortunately, contracting typhoid while abroad is rare, especially if vaccinated against it prior to travelling.

Malaria

Malaria is the most important serious disease facing travellers in developing countries. In 1996, 2500 people from the UK contracted malaria, the largest number since records began⁵. Malaria occurs mostly in the tropical areas of the world, where the climate is warm and moist. Throughout the world, malaria kills 1-3 million people a year⁶. Malaria is caused by a tiny parasite that lives in the salivary glands (spit glands) of a certain type of mosquito (the anopheles mosquito). When the mosquito bites a person, the malaria parasite is injected under the skin. The parasite, called Plasmodium, develops and multiplies in the liver and blood cells of the infected person. People infected with the malaria parasite experience episodes of high fever, sweating and shaking, which last for about 3 - 8 hours and happen every 2 - 3 days (depending on the exact type of malaria contracted) and are followed by chills and general tiredness.

Tuberculosis

Tuberculosis (TB) is caused by bacteria that usually infects the lungs, although it can affect almost any part of the body. TB is the most common infectious disease in the world, with about a third of the worlds' population infected⁷. TB is caught from people's saliva and phlegm, which is spread when victims cough. People infected with TB often lose weight and experience fevers and sweats, especially at night-time. The good news is that TB is not easy to catch. Recently, researchers in The Netherlands have shown that about three travellers out of every thousand become infected with TB per month of travel in an area where TB is common.

Accidents and Death

The cause of travel-related accidents and deaths is varied. They can occur on the way to a destination, during the visit to a country or upon return. Most injuries and accidents occur in young males, who often participate in adventurous and perhaps hazardous pursuits. A major cause of death in travellers is due to accidents, frequently road traffic accidents, but also due to drowning. Unfortunately many of these accidents are all too often associated with the consumption of alcohol. Another common cause of death is due to heart attacks in older travellers. Infectious diseases rarely cause death in travellers abroad.

A result of people having accidents while abroad, is that they may be exposed to serious blood-borne viruses including hepatitis B, hepatitis C and HIV, from blood transfusions or unsterilised medical instruments. Two-thirds of blood donations throughout the developing world are thought to be unscreened for infection. An organisation that provides screened blood for travellers who have been involved in accidents and require blood transfusions is:

The Blood Care Foundation,
16 Lonsdale Gardens
Tunbridge wells
Kent
TN1 1NU
01732 742 427

What Can be Done to Reduce the Risk of Illness Abroad?

Fortunately the health risks of travelling abroad are quite small, however the number of people becoming unwell while abroad, for whatever reason, is increasing. It is recommended that a consultation with a travel medicine expert be booked at least eight to ten weeks before travel, especially for those journeying off the beaten track.

What Does a Travel Health Expert Do?

Travel health experts are doctors who advise on all areas of keeping well while travelling. They will ask you the following questions:

• Where are you travelling to?
• When are you travelling?
• How are you travelling?
• Where will you be staying?
• How long will you be away for?
• What is the purpose of the journey?
• Will you be going to any other places?
• What activities will you be doing while away? – diving, trekking etc
• What medical conditions do you have or have had in the past?
• What immunisations have you had in the past, and when?

By knowing the answers to these questions, the travel health expert can advise you to take the appropriate precautions while visiting other parts of the world.

Travel health doctors can tell you what immunisations and tablets you need to take to reduce the risk of contacting an infectious disease while abroad, and can prescribe them to you. This advice depends very much on where you are visiting, and often whether you are going to be staying in a city or travelling into the countryside.

Visiting a travel health expert is also a good opportunity to discuss other important points about healthy travel. This includes advice about general precautions needed to help avoid common health problems and advice about safe sex.

What Precautions Can I Take to Keep Healthy When I Travel?

If you are going to a developing country you should be very careful about the food and water. A good motto to remember is 'boil it, cook it, peel it or forget it'. Remember, too, to wash your hands thoroughly.

Dos and Don'ts of food and water precautions

Use insect repellents and nets around your bed when in countries that have malaria. Nets impregnated with a chemical called permethrin can reduce your chances of being bitten by mosquitoes and contracting malaria⁸. Mosquitoes that carry malaria only bite between dusk and dawn. If you are out in the evening make sure you wear long-sleeved shirts and long trousers to reduce the chances of being bitten⁹. Burning mosquito coils (similar to candles) may also be helpful in reducing the number of mosquito bites¹⁰.

Even if you think it unlikely that you will have a sexual relationship while away it is best to take some condoms with you – just in case.

Try and avoid putting yourself in dangerous situations. If at all possible, avoid riding on motorcycles. If you do go on a motorcycle make sure you wear good protective clothing, footwear and a crash helmet.

Make sure you take a first aid kit with you on your journey, this should include bandages, plasters, alcohol wipes, disinfectant sprays or creams, tweezers, scissors, pain killers and basic antibiotics, anti-histamines and anti-diarrhoeal medications.

In hot countries ensure you do not stay out in the sun for too long, especially at the beginning of your trip. Take plenty of sun protection cream with you; use high sun protection factors to start with (above 20). Many local news and weather programmes will broadcast burn times (this is the length of time for a person out in the sun to burn). Remember to slip, slap, slop – slip on a shirt, slap on a hat and slop on the suntan lotion.

Travelling on an aeroplane for a long time can increase the chances of developing a blood clot in the veins of the legs (known as a deep venous thrombosis). This is due to blood clotting in the calf and leg veins because of inactivity. There are hardly any other times in life when you will sit still without a break for such a long time. To decrease the chances of this happening it is best to drink plenty of water on the flight and to get up and walk around for five minutes every hour. Avoid drinking a lot of alcohol, as this can make you dehydrated and increase the chances of developing a thrombosis.

What Do I Need to Take to Prevent Malaria?

Depending on where you are travelling you may need to take tablets to prevent you contracting malaria (called malaria chemoprophylaxis). If you are travelling to an area where contacting malaria is a risk, the number and type of tablets you should take depends upon exactly where you are going. A drug called chloroquine, used to be the standard drug used for malaria chemoprophylaxis throughout the world, but there are now many areas where this is not effective, as the malaria parasite has built up resistance to it. People travelling to Central and South America, Asia, South-East Asia and Sub-Saharan Africa should definitely seek travel health advice well before departure to make sure the correct tablets are taken.

Mefloquine (Lariam) is very effective in preventing malaria, however, there has been a lot of adverse publicity in the media about the serious side effects of it¹¹. However, side effects from mefloquine are relatively rare, with about 1 - 3% of people not tolerating it, usually due to feelings of sickness, sleep disturbance and vivid dreams. It has, in fact, been suggested that the most serious side effect of mefloquine is actually its tendency to cause hysteria in journalists that have never taken the drug¹². Serious mental health problems are very rare, and affect less than one person in every 10,000 taking the drug. This having been said, mefloquine should not be taken by people with previous serious psychiatric problems, epilepsy (either themselves or in close relatives) or in the first three months of pregnancy. To guard against serious side effects from mefloquine most travel health specialists advise that the traveller starts taking the tablets three weeks before departure. Tablets only need to be taken once a week. If any side effects happen an alternative drug can be prescribed well before leaving the country.

Doxycycline is an antibiotic that is an alternative to mefloquine. It is almost as effective as mefloquine in preventing malaria, but is less convenient, as it needs to be taken once a day, compared with the weekly doses of mefloquine¹³. Side effects from taking doxycycline include stomach upset, vaginal thrush, in women, and very rarely a skin rash which is made worse by sunlight.

There are other drugs that can be used to decrease the risk of contracting malaria while abroad. It should be remembered that taking malaria chemoprophylaxis does not completely remove this risk, and it is still possible to contract malaria while taking appropriate medications. All malaria chemoprophylaxis should be taken for four weeks after returning home. Travellers at increased risk of malaria include pregnant women and people who have had their spleen removed. People who have lived in areas of the world where malaria is common, but who have moved away, are also at risk of contracting malaria if they return because their immunity will have waned.

A combination of two drugs, atovaquone and proguanil (trade name Malarone) is often used for the treatment of malaria. There has been recent interest about its use in preventing malaria. A recent research study in Zambia showed that using Malarone as chemoprophylaxis provided 98% protection against contracting malaria¹⁴. As yet this drug is only licensed for the treatment of malaria, not for chemoprophylaxis in travellers, although it looks like this will change.

Specific advice about malaria and what anti-malaria treatment to take while away can obtained from:

Malaria Reference Laboratory (Recorded Information),
The London School of Tropical Medicine and Hygiene
Keppel Street
London WC1
0207 636 7921

Academic Centre for Travel Medicine and Vaccines
The Royal Free Travel Health Centre
Pond Street
London NW3 2QG
0207 830 2885

What About Alternative Medicines?

Research studies have shown that a few leaf, bark and root extracts from plants that grow in Asia and Africa are effective at treating malaria¹⁵, ¹⁶, ¹⁷. This is probably because chemicals that the plants contain, work in a similar way to the drugs that are given for the treatment of malaria. There is no evidence, as yet that these plants, or any other form of alternative medical therapy, is as effective as anti-malaria tablets.

A hundred and fifty years ago, well before we knew about malaria or bacteria in the water, Dr David Livingstone, the famous explorer, boiled all water and took quinine when he was in Africa¹⁸, in order to remain healthy.

It is advisable that all people visiting areas of the world where malaria is common should take proper anti-malaria medications. Malaria is a very serious illness and no risks to your health should be taken when travelling abroad.

What Vaccinations and Immunisations Should I Have?

The number and type of vaccinations you may need depends entirely on the part of the world you are visiting. Travellers often do not consider health issues when booking a holiday or trip abroad. If you are travelling to Africa, Asia, South-East Asia, South America or Eastern Europe it is recommended that you seek medical advice at least eight to ten weeks before you depart.

Most routine immunisations for travellers include hepatitis A, typhoid, tetanus, diphtheria and polio. Hepatitis A vaccine gives protection against infection in 98% of people within ten days of it being given. A booster is usually given six to 12 months afterwards, this offers long-term protection against infection for up to 20 years¹⁹. In the UK, the polio vaccine is usually given live via the oral route and is excreted, live, in the faeces. If someone who has not been vaccinated against polio, comes into contact with this faeces, there is a very small theoretical chance of contracting the disease.

Typhoid vaccine is recommended for those travelling to Africa, Asia, Central and South America and some Eastern European Countries where hygiene and sanitation are often poor. A booster is required every three years for those who regularly visit these areas²⁰.

Since 1991, diphtheria has re-emerged in the newly independent states of the former Soviet Union and since the fall of the Iron Curtain this area has held increasing fascination for travellers²¹. Diphtheria vaccinations, together with tetanus and polio immunisations, have routinely been given to children since 1940. An adult who has never received either diphtheria or tetanus vaccine and who is travelling to an area where diphtheria is a risk should be immunised with three doses of tetanus/low dose diphtheria (Td) vaccine, given one month apart. All travellers to such areas over the age of ten years should be given boosters of diphtheria and tetanus vaccine.

Vaccines to be considered include Japanese Encephalitis, which is recommended for travellers visiting rural areas of South East Asia and the Far East for longer than a month²². Rabies vaccine is recommended for people travelling to areas with high numbers of rabid animals and who may be a long way from medical help²³. Yellow fever vaccine is legally required for travellers visiting specific areas of Africa and South America²⁴. People receiving the vaccination are issued with an International Certificate of Vaccination, which is valid for 10 years. Likewise meningitis vaccine is essential for people visiting Saudi Arabia during the hajj (the pilgrimage to Mecca which all Muslims are expected to make at least once). The reason for this is that there are so many people, in such close proximity to each other, that in times past, there have been outbreaks of meningitis. It is also recommended for people travelling rough while abroad.

So, Should I Visit a Travel Health Expert?

If you are travelling to Asia, South-East Asia, Eastern Europe, Africa or Central and South America it is recommended that you obtain good travel health advice at least eight to ten weeks before your departure. Visiting a travel health expert is a good opportunity to find out and discuss the various risks that you may be exposed to while away. Also, to discuss sexual health and safe practices for sex, and if necessary to receive hepatitis B vaccination²⁵. It is also a good time to check that BCG vaccination against TB was given when you were at school²⁶. If you do not have a scar on the upper part of your arm, you will need to have a test for TB immunity.

Is There Anything Else I Should Do?

There are many people who take short but frequent periods of travel, as well as those who travel for longer periods of time. Such travellers should have a medical check-up if they become unwell within six weeks of returning home, especially if they have been to a developing area of the world.

Blood tests are useful to identify both past exposure to infectious diseases as well as blood group (useful in case of an accident or illness that requires a blood transfusion). HIV testing is required as part of the entry requirements for certain countries such as the Russian Federation, the USA and Australia if you plan to work there. Counselling must be provided before a test is performed.

Travel health advice may be obtained from travel clinics at general practice surgeries or from independent travel clinics, including:

The Royal Free Travel Health Centre
Pond Street
London NW3 2QG
0207 830 2885

The Liverpool School of Tropical Medicine
Pembroke Place
Liverpool
L3 5QA
0151 708 9393

The Scottish Centre for Infection and Environmental Health
Clifton House
Clifton Place
G3
0141 300 1100

The Department of Infection and Tropical Medicine
Heartlands Hospital
Bordesley Green East
Bordesley Green
Birmingham
B9 5SS

Recommended web sites include:

• www.open.gov.uk/doh
• www.fco.gov.uk/travel
• www.fitfortravel.scot.nhs.co.uk
• www.travel-health.co.uk
• www.cdc.gov
• www.who.int
• www.istm.org
• www.medicineplanet.com