stages, and may be confused with malaria, typhoid, other hemorrhagic fevers (dengue, Rift Valley, Venezuelan, Bolivian, Argentine, Lassa, Crimean-Congo, Marburg and Ebola), rickettsial infection, leptospirosis, viral hepatitis , other causes of liver failure and toxic hepatitis (e.g. carbon-tetrachloride poisoning). Exams and Tests A person with advanced yellow fever may show signs of