A serious viral infection with the potential for long term consequences. It is caused by a DNA virus that has been found in virtually all body secretions and excretions. However, only blood, saliva, semen and vaginal fluids have been shown to be infectious. Transmission occurs through sexual contact, blood-to-blood contact (blood products, needle sharing, etc.), and from infected mother to infant. Virtually all affected infants and children, and many adults, receive a lesser, even symptom-free, infection. Symptoms, when present, tend to be more severe and prolonged than those for Hepatitis A: 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.