After a violent confrontation in which miners killed four Indians and the Yanomami killed four miners in retaliation, government officials moved in.

“But instead of evicting the miners, they evicted the missionaries and the medical teams” who were aiding the Indigenous people, recalled Zacquini, 82.

By the time the Consolata missionaries were allowed to return to their mission on the Catrimani River several years later, “there were thousands and thousands of miners,” Zacquini said.

With the miners came violence and diseases like malaria, to which the relatively isolated Indians had no resistance. In one village, no one survived. In others, as many as one-third of the villagers succumbed, some to disease and others to malnutrition.

“Many Yanomami died,” Zacquini said. “No one will ever know how many.”

Encounters with outsiders, followed by violence, disease and death, are a tragic pattern in the history of Amazonian Indigenous people since Europeans first ventured into the lowlands nearly 500 years ago. Diseases to which the people had no immunity swept ahead of the colonists, decimating the population.

The cycle of disease and violence recurred as fortune seekers invaded and plundered Indigenous territories for timber, the meat and hides of wild animals, gold and oil. And it continues today, threatening some of the last people on Earth who live in the forest as their ancestors did, shunning contact with the outside world.

“The Amazon is rich in water, timber, underground minerals, wild game and other things, and white people are utilizing it,” said Davi Kopenawa, a Yanomami shaman and a spokesman for his people. He remembers when tens of thousands of miners invaded his people’s lands.

“I suffered greatly, because our place was polluted and dirty,” he told Catholic News Service. “There was sickness. They killed my relatives. But the government did not evict them.”

Although the Brazilian government finally created a territory for the Yanomami people, miners continue to invade and Kopenawa said his people continue to die.

As many as 5,000 gold miners continue to work illegally in Yanomami territory, turning the forest into huge barren, cratered swaths of land and poisoning the water and fish with the mercury they use to extract the precious metal, he said.

“Gold mining is a disease, and it creates disease” with the mercury, oil and gasoline used in pump motors, which also spill into the rivers, Kopenawa said. “It kills the life of the Indian, the white man, the river and the fish.”

Health experts say miners brought diseases like malaria and tuberculosis into the region, as well as sexually transmitted illnesses. Most recently, a measles outbreak swept through Yanomami groups, probably introduced by miners from Venezuela, which is suffering from a measles epidemic.

At greatest risk are several groups of Yanomami who live in the forest. Seven South American countries are home to such isolated people, but the largest concentration is in Brazil, mainly along the heavily forested border with Peru.

The Brazilian bishops’ Indigenous Missionary Council — known by its Portuguese initials as CIMI — has helped Indigenous groups win the designation of territories in places where there are still isolated people.

CIMI has begun to refer to isolated groups as “free Indians,” to underscore the fact that they have made a choice about how they want to live, said Guenter Francisco Loebens, a 40-year CIMI veteran who specializes in issues related to isolated groups.

Pope Francis spoke of those groups when he met with Indigenous people in Puerto Maldonado during his visit to Peru in January 2018.

Calling them “the most vulnerable among the vulnerable,” he urged his listeners to “continue to defend these most vulnerable brothers. Their presence reminds us that we cannot consume common goods at a greedy pace.”

The working document for the Synod of Bishops for the Amazon notes that isolated groups are at particular risk from industrial activities such as mining, logging, large-scale agriculture, construction of dams and roads, and drug traffickers who pass through the territories they inhabit.

The document calls for the Church to demand that governments protect isolated groups and the territories they inhabit. The groups should be protected as long as they avoid outsiders, but allowed to initiate contact when they choose to do so, the document said.