Since the number of divers travelling abroad in search of new and exotic locations is on the increase, there is a growing need for information about health protection in foreign countries.

We all look forward to our trips abroad but the experience can be spoiled if we become unwell whilst away.

Fortunately, most minor complaints associated with travel such as holiday tummy, diarrhoea, travel sickness, sunburn, insect bites, etc. can easily be treated by carrying the appropriate remedies in a basic medical kit and a first aid kit:-

For an example of a basic medical and first aid kit:-

However, since most of the world's exotic dive locations are to be found in and around developing countries and the tropics, there is a risk of contacting a more serious illness like malaria, yellow fever, typhoid, hepatitis, etc. There is therefore, a need to be protected against them, usually by vaccinations prior to travel and by taking tablets during and after the trip.

The table below contains information about vaccination requirements and malaria prophylaxis for travellers going abroad and contains most of the countries likely to be visited by divers going on diving holidays and expeditions.

In addition to malaria tablets and the various vaccinations required, persons travelling to developing countries are strongly advised to carry a medical kit containing a number of medical and first aid items.

The list of countries in the table below is by no means exhaustive and should only be used for quick reference purposes. The data in the table only applies to healthy adults. Travellers will need to consult their own doctor to arrange to have the relevant vaccinations.

The advice in the table is for travellers visiting a single country and arriving directly from the UK. It is intended for use by persons planning a short stay i.e. less than three months.

Specialist advice should be sought by persons intending to live abroad for long periods or for persons travelling between countries. For long stays (over three months) and for trips to remote areas, vaccines not mentioned below such as Rabies, Diphtheria or Hepatitis B may be required.

The information is not designed for use by pregnant women, nursing mothers, children or persons suffering from epilepsy or any other chronic condition who should consult their doctor before taking malaria tablets.

No particular immunisation or malaria prophylaxis is required for direct travel to Europe, U.S.A., Canada, Australia or New Zealand. However travellers should be advised to make sure that they have had a tetanus booster within the previous ten years.

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Malaria Prophylaxis

Malaria tablets should be started one week before entering the malarious zone, taken throughout the duration of the stay and continuing for at least four weeks after return without fail. All tablets should be taken with or after food, preferably with the main meal of the day.

Patients with a history of psychiatric disturbances (including depression) should not take mefloquine as it may precipitate these conditions. It is now advised that mefloquine be started two and a half weeks before travel. No other tablets are required with mefloquine or doxycycline. Mefloquine can be taken for periods up to one year, doxycycline should not be taken for periods longer than three months. Doxycycline does carry some risk of photosensitisation.

Please Note:
No prophylactic regimen
is 100% effective.

Some forms of malaria can develop seven days after being bitten by an infected mosquito and others can incubate for even longer. Typical symptoms of malaria are bouts of high fever lasting several hours starting dramatically with shaking chills, subsiding with profuse sweating, and reappearing at regular intervals, most commonly every 48 hours. Anybody experiencing any of these symptoms (which could be confused with flu) within twelve months of returning from a malarious zone should seek medical advice immediately. Deaths have occurred in cases where where the symptoms have been ignored until it is too late!

Since protection against the malaria parasites may not be complete it is important that measures are taken to avoid getting bitten by mosquitoes:-

• Sleep in screened rooms, using a fly killer spray to kill any mosquitoes that may have entered the room during the day.
• Use mosquito nets around the bed at night. Check that there are no holes. Tuck the net under the mattress.
• Wear long sleeved clothing and long trousers when outdoors after sunset. Light colours are less attractive to mosquitoes.
• Use repellents such as diethyl toluamide (DEET) on exposed skin or wear DEET impregnated wrist bands and anklets.
• Clothing and mosquito nets can be impregnated with a solution of 30ml DEET in 250ml water.

Remember:
Malaria can be fatal! 

Malaria is a disease which you can catch by being bitten by a mosquito carrying the malaria parasites in its saliva. The species of mosquito that carries the malaria parasites is the Anopheles mosquito.

These parasites then enter your bloodstream and travel to your liver where they multiply and are released back into the bloodstream in large numbers which then invade red blood cells.

They continue to multiply until the red cells burst releasing large numbers into the blood plasma causing the characteristic fever associated with the disease. This phase of the disease occurs in cycles of approximately 48 hours.

The free parasites are then able to infect any mosquito that feeds on your blood during this phase. The cycle then continues as the parasites multiply inside the mosquito and invade its salivary glands.

The malaria parasite is a microscopic organism called a Plasmodium and it belongs to the group of tiny organisms known as protozoans. There are four types of plasmodium: P. falciparum (the most dangerous), P. vivax, P. ovale and P. malariae.

Anybody travelling to an area where this mosquito is endemic is at risk of catching the disease. Lately there has been an increase in the cases of malaria reported in the UK - in 1993 there were 1922 reported cases in the UK, including five deaths. All caught the disease abroad and almost all cases could have been prevented.

Typhoid

The original typhoid vaccine was given in two doses at intervals of four to six weeks and gave immunity for up to three years. 0.5ml was given by subcutaneous or intramuscular injection or 0.1ml by intradermal injection. This vaccine induced a mild form of the illness which could be very unpleasant in certain cases.

Typhim Vi is a single dose vaccine where 0.5ml is given by deep subcutaneous or intramuscular injection. Immunity lasts for approximately three years.

Vivotif is a live oral vaccine contained in an enteric coated capsule. The vaccine is taken as three doses of one capsule on alternate days. The capsules should be stored in a refrigerator between doses. Protection begins seven to ten days after the last dose.

Tetanus

The Department of Health recommends administration of reinforcing doses after ten years, with the administration of further doses in the event of injuries that may give rise to tetanus. 0.5ml is given by deep subcutaneous or intramuscular injection.

Polio

Poliomyelitis vaccine is recommended for long term travellers to areas which have a high incidence of the disease such as developing countries. Live oral vaccine is generally used. Three drops of the vaccine constitutes a single dose. Initially three doses are given at intervals of at least four weeks. Those who have been fully immunised in the past will only need a single booster dose every ten years if they intend to travel.

Hepatitis A

Hepatitis A is associated with poor hygiene and sanitation. Havrix Monodose is an inactivated vaccine prepared from the hepatitis A virus. A single 1ml dose is given intramuscularly to give immunity up to one year. To obtain immunity up to ten years a second booster dose is given between six and twelve months of the original.

Human Normal Immunoglobulin (HNIG) contains antibodies to Hepatitis A and will give protection for up to three months. 2ml of vaccine is administered by deep intramuscular injection.

Yellow Fever

This is given as a live vaccine (0.5ml subcutaneously) at designated yellow fever centres where an international certificate of vaccination will be issued and is valid for ten years, from ten days after vaccination. The certificate may be required for entry into certain countries particularly in East Africa. It is recommended that the traveller carries the certificate along with his or her passport when travelling to countries at risk.

Meningitis (A&C)

Meningitis vaccine is recommended for travellers to areas where the disease is endemic such as most of Sub-Saharan Africa. Saudi Arabia requires vaccination of pilgrims to Mecca during the Hajj. 0.5ml of inactivated vaccine is given by deep subcutaneous or intramuscular injection. Immunity lasts up to three years.

Japanese B encephalitis

This is a rare but serious insect borne disease that occurs in most of the Far East and South East Asia. Vaccination is recommended for stays of longer than one month in rural areas during and just after the rainy season. The vaccine is issued on a named patient basis and is given as 1ml subcutaneously for immunity up to four years.

VACCINATION SCHEDULES

• Inactivated vaccines usually require one primary dose followed by one or more booster doses given at intervals of around four weeks. If time is short, a single dose will give some protection. Most inactivated vaccines can be given together safely; inactivated and live vaccines can also be administered simultaneously.
• When two live vaccines are required, they should be given either simultaneously at different sites or with a gap of at least three weeks. Oral polio vaccine should not be given at the same time as oral typhoid vaccine.
• Human Normal Immunoglobulin (HNIG) may interfere with the immune response to live vaccines and so should not be administered simultaneously. A live vaccine should ideally be given three weeks before or three months after an injection of HNIG. However, HNIG is unlikely to contain antibodies to the yellow fever virus and so they can be administered simultaneously. Oral polio vaccine when given as a booster can also be administered simultaneously with HNIG.

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