This was an article that caught me by surprise: Peruvian Amazon tribe warns it's close to extinction. When I saw the headline, I was probably expecting the reason to be something like deforestation, societal encroachment, tropical disease, parasites, etc. -- basically not HEPATITIS B.

One tribal member attributes the introduction of the disease in the 1990s, when an oil company was given rights to explore the region, and has then gone "unchecked since 2000." Now the future of the tribe is uncertain as liver cirrhosis and cancer rates rise, in the absence of medical care.

On a side note, I'm not sure if they're succumbing to acute or chronic Hep B. Because the disease might be novel to them, perhaps the chances of an acute infection going chronic is higher than what we'd expect from otherwise healthy adults.