Xuxu wants a metal cooking pot big enough to hold a whole monkey. Not long ago, his people, the Korubo, cooked meals in ceramic cauldrons made in the forest. But lightweight metal pots brought by “white people” have proved irresistible.

Xuxu says he first became aware of the existence of Tabatinga, a municipality in the state of Amazonas, Brazil, when he visited for a snakebite, moving an armband on his powerful right biceps to show where the serpent got him. The second time, he accompanied a sick grandchild.

Xuxu lives in one of the four Korubo villages near the confluence of the Ituí and Itaquaí rivers in the Javari valley Indigenous territory, where the 127 Korubos were contacted in total, across four villages, in 1996, 2014 and 2015. A decade on, the aftermath has brought diseases, new materials, increased safety from outside threats and a window into the wider world.

The Korubo account for all but one of Brazil’s recent first-contact events, showing what might await more than 60 uncontacted Amazonian groups should they emerge. Their lands were initially occupied by rubber tappers in the late 1800s, followed by loggers in the 20th century. The Korubo resisted with palm-wood clubs, a unique characteristic among Amazonian peoples as they do not use bows and arrows.

“They were like a shield for the territory,” says Fabrício Amorim, formerly the National Foundation for Indigenous Peoples (Funai)’s coordinator in the Javari valley. “They faced off against groups of loggers who would have 10, 15, 20 boxes of ammunition and plenty of guns, and the Korubo just carried these pieces of wood.”

Between 1965 and 1997, the Korubo killed 25 non-Indigenous intruders in their home territory. Their adversaries launched several hunts, tracking, shooting and poisoning Korubos. “We were in our maloca [long house], and the white people arrived and killed a lot of my family members, our elders,” says Xuxu. “That’s why we took revenge, killing fishers.”

By the mid-1990s, the violence prompted Funai to establish contact, breaking their policy of avoiding communication. Expedition leader Sydney Possuelo initiated contact in 1996, bringing the world images of 18 naked individuals, led by the Korubo matriarch, Mayá, inspecting modern contraptions and trying on clothes.

Today, at least one Korubo group remains uncontacted.

In the Tabatinga Indigenous health centre’s yard, Xuxu and his older brother Txitxopi snap boughs off a tree to make seats for themselves and their visitors. Serial contacts have created two social classes: xëni (originals) and paxa (newcomers). Xuxu is paxa. His hair is traditionally styled, with the back shaved close and bangs trimmed straight across. He stifles laughter several times, finding the conversation hilarious.

“We don’t like it here in the city. We come down here from the village and sometimes catch another disease,” says Takvan, son of the matriarch, Mayá. “That’s why we are fighting for Sesai [the federal secretariat for Indigenous health] to make a big health clinic with a doctor and medical assistant to work with us in the village.”

The Korubo have a health post in one village and a floating clinic near another, yet they keep coming to the city for care and end up getting sick. Dr Lucas Albertoni, Brazil’s chief official for recently contacted peoples, has observed that Korubos now come to the city even for minor medical issues – a reversal from earlier days when it was difficult to persuade them to leave the forest.

“Now it’s the opposite,” he says. “I have to convince them of all the [negative] consequences of trips to the city.”

Four Korubo infants have died in the past year. The cause of death for two of them has not yet been revealed, but preliminary analyses indicate familiar problems: flu, pneumonia, diarrhoea and dehydration.

“Biologically, we are exactly the same. This [Korubo] population isn’t immunologically fragile,” Albertoni says. “It’s a lack of immunological memory for disease agents that circulate in our society.”

Several years after contact, Funai attempted to regulate the flow of manufactured products into the Korubo orbit. It delivered straight to the villages a set list of things that they “needed” – batteries, electric torches, lighters, sharpening stones, machetes, axes, soap. But the Korubo concept of needs evolved. With money from Funai jobs and government transfers, they bought boats, mobile phones, rice, pasta, biscuits and other items. Brazilian currency features animals, helping non-numerate Korubo keep track: a jaguar prowls the 50 real note (£6.70) and buyers know the number of “jaguars” required for purchases.

“Sometimes they cheat us,” says Takvan.

Now, the Korubo want solar panels to provide electricity for lighting, charging phones and powering internet connections. “Before mobile phones, before the internet, when someone was taken to the hospital in the city – my son, my brother – we wanted to know how they are. Are they better or worse? How do we find out? That’s why we have mobile phones now, and we want Starlink,” says Txitxopi.

Two villages already have internet connections. Luisa Suriani, who teaches Portuguese and literacy in the villages, says plans to limit access to certain hours didn’t work. “Now one village has access to an internet service that’s on all day,” she says. “They are naturally fascinated with everything that comes from outside, so just imagine the internet.”

The longhouse glows with screens and Suriani says that the young people are increasingly resistant to survival tasks such as hunting and cultivation.

Seatvo is the first Korubo to live in the city. When he met anthropologist Juliana Oliveira in Tabatinga, he wore tight jeans, immaculate white sneakers and sunglasses on his head. Once a translator at the health centre, he’s looking for new options, possibly in the army. Eventually, he wants to train as a teacher and return home: “We are tired of teachers who stay for only three months and then leave,” he says.

Suriani cautions against romanticising the Korubo or lamenting their “pollution” by materialism. “When you spend time living with them in the villages, you see what a strong, completely unique people they are,” she says.

She marvels at how women wash babies as if shaping them, and how, in the longhouse, someone might be weeping for a lost pet monkey while men drink tatxi (a traditional beverage made from tree bark), laugh and chat. “Korubo day-to-day life is completely vibrant,” Suriani says.

Yet dilemmas remain. The Korubo are glad their population is growing, but game has become scarce. “When we first built our maloca, there were lots of game. We hunted and hunted, and then the animals were far away,” says Takvan. Before, the Korubo would move, but now they are tied down by goods, services and the convenience of proximity to the city.

The ethnologist Possuelo says: “The post-contact suffering is very great … They fall into a dependency on those who formerly killed them, hunted them, took their land, stole their women, who did everything to them. Those are the same people now in command of their lives. ‘You can do this, you can’t do that, you have to wear clothes, don’t wear clothes,’ etcetera.”

About the uncontacted, he says: “Let them live happily in their territory for as long as possible.

“The least we can do is to keep a respectful distance. Leave them alone. If the state wants to do something good for isolated people, it should preserve their isolation. Protect nature so that they can live as they always have.”

Xuxu gets off the health centre van at the port, looking a little lost. He carries his hammock and a woven basket of belongings. Txitxopi guides him to a nearby shop where Xuxu enthusiastically examines various cooking pots.

Soon, the transaction is done. The two Korubo men make their way to a fruit stand to buy tangerines and grapes before dodging traffic hand-in-hand, crossing to the wharf and the boat waiting to take them back to the forest.