Lábrea fever (also known as Lábrea's black fever, Lábrea hepatitis or Santa Marta fever) is essentially a coinfection of Hepatitis B Virus and Hepatitis D Virus. This combination results in a lethal infection, which may kill patients in less than a week. It characteristically affects children and young adults, and more males than females.
This disease was first discovered in the 1950s in Lábrea, a city situated deep in the Brazilian Amazon jungle but has been reported in Brazilian Amazon as early as the 1930s. The disease has also been diagnosed in neighbouring Colombia, Peru and Venezuela. In Colombia the disease has been named Santa Marta fever.
The onslaught of the infection occurs suddenly and quickly, and is intense and severe to the point of lethality. In many cases it is accompanied by an encephalitis. In a study carried out in the Boca do Acre district (Brazil), 39 patients out of 44 died, which resulted in a staggering case fatality rate of nearly 90%. Survivors may develop chronic disease.
Lábrea fever has a sudden onset, with jaundice (yellowing of the skin), anorexia (lack of appetite), hematemesis (vomiting of blood), headaches and high fever. Death occurs by extensive destruction of liver tissue and acute liver failure.
My suggestion: get yourself vaccinated against Hepatitis B Virus as quickly as possible.
 Parana et al: Virological and histological re-evaluation of Labrea hepatitis in Acta Gastroenterologica Latinoamericana - 2008
 Bensabath et al: Hepatitis delta virus infection and Labrea hepatitis. Prevalence and role in fulminant hepatitis in the Amazon Basin in Journal of American Medical Association - 1987