Hepatitis D (delta hepatitis) is caused by a virus that is dependent upon co-infection with hepatitis B-it will only cause an infection if hepatitis B is also present. The epidemiology of hepatitis D is essentially identical to that of hepatitis B.
Hepatitis D can be transmitted from a pregnant woman to her baby in the same manner as hepatitis B. This is extremely uncommon, however, since the vaccination for hepatitis B, when given to newborn infants, is almost uniformly effective against hepatitis D.
Acute hepatitis D occurs in two forms: co-infection and superinfection.
- In co-infection, acute hepatitis B and D occur simultaneously. It is usually a self-limited disorder (which will clear up on its own) and rarely leads to chronic liver disease.
- Superinfection occurs when acute hepatitis D develops in a patient who is a chronic hepatitis B carrier. Approximately 20 to 25% of patients with chronic hepatitis B ultimately become superinfected with hepatitis D and about 80% of these individuals eventually develop chronic hepatitis. Of those who have chronic hepatitis, 70 to 80% develop cirrhosis and portal hypertension (involving obstruction of the portal vein within the liver). Almost 25% of these patients will die of liver failure.
The clinical signs and symptoms of acute hepatitis D include:
- malaise (a general feeling of being sick);
- poor appetite;
- nausea and vomiting;
- pain or tenderness in the area of the liver;
- darkened urine;
- lightened stool; and
- jaundice (yellowing of the skin and the whites of the eyes).
Some patients infected with hepatitis D do not have any symptoms until chronic liver disease develops.
Hepatitis G (HGV or GBV-C) is a recently discovered virus that is related to hepatitis C. Hepatitis G can cause a chronic carrier state and transmission of the virus from mother to baby has been documented. However, at least at the present time, there is no information indicating that hepatitis G infection poses a serious problem for either the mother or her baby.
Hepatitis G can cause acute and chronic infections. The disease is usually mild, and the clinical significance of infection is uncertain. Persistent infection is usually not associated with serious injury to the liver, and the virus clearly seems to be less virulent (dangerous) than hepatitis C. Hepatitis G infection often occurs in association with hepatitis A, B, and C, or with HIV-conditions which pose a much greater risk for the patient.