Waiapi men stand at the Tucunapi river in the Waiapi indigenous reserve in Amapa state in Brazil on October 14, 2017. Tribal chieftain Tzako Waiapi perfectly remembers the day almost half a century ago when his hunting party stumbled across a group of white adventurers in the Amazon rainforest. Within months, nearly everyone in his entire tribe had died from disease. / AFP PHOTO / Apu Gomes / TO GO WITH AFP STORY "When the Waipai tribe almost died out" by Sebastian SmithAPU GOMES/AFP/Getty Images