Indigenous rights advocates in Brazil are constantly faced with the possibility of history repeating itself -- and wiping out some of the tribes that still live in the Amazon.

Most recently, seven members of the Ashaninka tribe contracted the flu, and if they had been untreated could have infected their entire tribe, according to Fox Latino.

The dangers of simple respiratory illnesses is amplified for these tribes, especially those with limited or no previous contact with the outside world. They are not vaccinated and have no natural immunity to the infections.

A well-known example is the extinction of Cuba's Taino tribe when Christopher Columbus landed on the island.

Rebecca Spooner, a campaign officer for Survival International, a British non-governmental organization, told the Washington Post that for recently contacted Indian tribes, like the Ashaninka, simple respiratory diseases can be deadly.

"It's very common for half the tribe to be wiped out within a few months of contact," Spooner said.

The most recent scare occurred with the Ashaninka tribe when two females and five males, aged 13-21, met with members of a settlement just over the Peru border, and developed flu-like symptoms.

"The nightmare scenario is that they return to their former villages carrying flu with them," said Stephen Corry, director of Survival International, Fox Latino reported. "It's a real test of Brazil's ability to protect these vulnerable groups."

Brazil is faced with the task of protecting 818,000 indigenous peoples, in a number of contacted tribes and 77 uncontacted tribes, according to a 2010 census, the Washington Post reports. The total population at that time was 191 million.

"There is a huge amount of conflict in the Amazon at the moment," Spooner said.

Indians are fleeing into Peru -- both contacted and uncontacted tribes -- because illegal logging, oil and gas exploration and drug trafficking are threatening their homes.

But the incident with the seven who had to be vaccinated for the flu spurred a meeting to try and tackle future issues.

Brazilians indigenous affairs department (FUNAI) President Maria Assirati and FUNAI's coordinator for isolated and recently contacted tribes Carlos Travassos, along with other specialists, met to discuss contingency plans in the event of future contacts.