These are diseases caused by viruses that attack a person's liver.
Hepatitis B viruses are transmitted through sexual intercourse, transfusions with contaminated blood and from mother to child through the placenta. Symptoms of hepatitis B include jaundice, fever, headaches, nausea, vomiting and muscle aches.
The disease can become chronic in about 10% of infected people and cause cirrhosis and liver cancer.
Hepatitis C viruses were discovered in 1989 and are transmitted as hepatitis B viruses. The disease is usually asymptomatic, but some individuals may develop jaundice and may suffer from headache and sore throat, vomiting and fatigue.
The biggest danger is the disease progressing to liver cirrhosis, in addition to the risk of liver cancer. In Brazil, it is estimated that 3 million people carry the hepatitis C virus.