UNcontacted peoples are peoples who, either by choice or chance, live, or have lived, without significant contact with the 'modern' civilizations of the world.
Recent usage favors the term "isolated" rather than "uncontacted" as few peoples have remained totally uncontacted by modern civilization, but a number have chosen to make contact either exceedingly difficult or dangerous. Many indigenous rights activists call for such groups to be left alone in respect of their right to self-determination.
A problem with making contact with isolated peoples is that they lack any immunity to common diseases which explorers, trying to make contact with them, will inevitably carry. This can have severe consequences as normally minor diseases, such as the common cold, can be deadly when no natural immunity exists.
There are several uncontacted tribes in New Guinea and Amazonia, including the Tagaeri band of Huaorani (Ecuador) and Kirineri, Nahua and Nanti peoples in the Nahua-Kugapakori Reserve (Peru). In May 2008, the Brazilian government released photographs and new information about an isolated tribe living near the Peruvian border; they have decided to make the information public now because the tribe's habitat is in danger due to logging, much of which is illegal and unregulated. Although the Brazilian Government have had some knowledge of the tribe's existence since 1910, no contact has been made. Many advocate increased awareness of the danger that this tribe and other isolated groups face. http://www.survivalfrance.org/actu/4026