Caused by an RNA flavivirus. Transmission is predominantly through broken skin on contact with infected blood or blood products, especially through needle sharing. Sexual transmission is relatively rare. Symptoms are almost always present, and very similar to those for Hepatitis B: initially flu-like, with malaise, fatigue, muscle pain and chest pain on the right side. This is followed by jaundice (slight skin yellowing), anorexia, nausea, fatigue, pale stools, dark urine and tender liver enlargement, but usually no fever.