1. Concepts related to health 1.1 World Health Organisation (WHO) The WHO is a specialized agency of the United Nations (UN) that is concerned with international public health. It was established on 7 April 1948, with headquarters in Geneva, Switzerland. Since its creation, WHO has been responsible for playing a leading role in the eradication of smallpox. Its current priorities include communicable diseases, in particular, HIV/AIDS, malaria and tuberculosis the mitigation of the effects of noncommunicable diseases sexual and reproductive health, development, and aging nutrition, food security and healthy eating occupational health substance abuse and drive the development of reporting, publications, and networking. 1.2 Health certificates Global travel on this scale exposes tourists to a range of health risks. Many of these risks can be reduced by taking precautions before the start of a journey. A health certificate is an official document that is issued and signed by a health authority. It confirms that an individual has received the vaccine or prophylactic as indicated on the certificate. 1.3 Travel clinics The spread of infectious diseases from one part of the world to another is not something new but it remains a concern. Travel clinics providing up-to-date specialised international travel healthcare. 1.4 Vaccinations Millions of deaths have been avoided because of worldwide immunisation programmes against infectious diseases. For tourists this is important as safe and effective vaccines help to reduce the possibility of contracting a disease when travelling to high-risk destinations. Compulsory vaccinationsThe WHO decides which vaccinations are compulsory. Recommended vaccinations These vaccinations are not enforced but are recommended as a precaution. 2. Precautions to take when travelling to high-risk destinations Destinations are considered high-risk if they are in regions that pose a threat to the health of the tourist. Areas where malaria, bilharzia and cholera are found are high-risk destinations.