Travelling some place away from home? Immunizations are needed to ensure a safe holiday. In some less-developed countries, the sterility of medical equipment is not guaranteed. The best advice if you are travelling in such areas is to avoid medical or dental treatment involving surgery, blood transfusion or injection, if at all possible.

Another precaution you may wish to consider is that of taking your own emergency medical kit containing sealed, sterilized equipment such as syringes, needles and suture materials. In any emergency, give the sealed kit to the doctor or nurse treating you so that you know the equipment used on you is safe. Personal kits are advised for travellers going to destinations including Goa in India, the Kenyan coast, sub-Saharan Africa, Egypt outside Cairo, rural Thailand, Mexico and Central America (outside tourist resorts), and for most of South America. They are available from chemists and at private travel centres.

If possible, you should ask your travel agent or doctor about immunization at least two months before you are due to leave. Some immunizations take time to become fully effective, and some cannot be given at the same time as others. If you are taking children with you, it is important that they have had their full course of normal childhood immunizations. If you need antimalarial medication, your doctor will be able to advise on the best type, including varieties available over the counter in pharmacies. Although certain immunizations are free on the NHS, you may have to pay for others.

DISEASE -- RISK AREAS -- MEANS OF INFECTION -- IMMUNIZATION

Cholera -- Africa, Asia, Middle East. -- Contaminated water or food. -- Two injections, 7-28 days apart.

Polio -- Everywhere except Australia, New Zealand, North America, Europe.
-- Direct contact with infected person; contaminated food and water. -- Three drops taken orally.

Hepatitis A -- Most parts of the world -- Contaminated food or water. -- One injection or a skin-scratch vaccine.

Hepatitis B -- Worldwide -- Sexual contact with infected person; injection with contaminated blood or needle. -- Three injections over six months.

Malaria -- Africa, Asia, Central and South America -- Bite from infected mosquito. -- Course of tablets beginning a week before travel and
ending 4 weeks after return.

Rabies -- Many parts of the world. -- Licks, bites or scratches from any animal. -- Pre-exposure vaccine if you are going to a remote, high-risk area.

Diphtheria -- Main risk is in countries of the former USSR, and in developing regions. -- Airborne bacteria. -- If not immunized, three injections a month apart. Low-dose adult vaccine must be boosted every five years.

Typhoid -- Everywhere exept Australia, New Zealand, North America, Europe. -- Contaminated food, water or milk. -- One injection or four doses of oral medication over eight days.

Yellow fever -- Africa, South America -- Bite from infected mosquito. -- Single injection.