Hepatitis viral delta

Abstract

The etiologic agent of this severe form of hepatitis was identified by Rizzetto et al in Italy in 1977. The Delta virus resembles satellite viruses of plants which can not replicate without another specific virus. In this particular case hepatitis B virus is the helper agent. Clinically this form of hepatitis is characterized by two presentations: coinfeccion, which means simultaneous infection of a host with hepatitis B virus and hepatitis D virus. This variety of hepatitis can present with two distinct peaks of transaminases and usually resolves completely in most of the cases, however 0-4% can evolve to chronic hepatitis and 25% of the cases of fulminant hepatitis are due to this viral association. The diagnosis can be established demonstrating anti-HDV IgM or HDV-RNA or HDV antigen in the serum.

In essence coinfection makes acute hepatic failure more common and the mortality is significantly higher than hepatitis B infections by itself. The second type of clinical presentation is superinfection, which means infection with the Delta virus of a patient previously infected with the hepatitis B virus (healthy carrier). Initially the patient develop a typical acute viral hepatitis in 50-70% of the cases, and 30-50% can have asymptomatic infection. The real problem with this presentation is that 20-90% of the cases evolved to chronicity: chronic active hepatitis and cirrhosis. The diagnosis can be made demonstrating anti-HDV IgM and anti-HDV IgG, although this last one is usually transitory. A liver biopsy can show HDV RNA or HDV antigen using special immunostainings. The epidemiology of Delta hepatitis is very similar to hepatitis B, and the agent is transmitted mainly through blood transfusions, IV drug addiction, perinatally, sexually and in some areas in Latinamerica through cutaneous lesions.

The prevalence in the world is similar to hepatitis B with areas of low endcmicity, less than 1%: (USA, Canada, Northand Western Europe, South part of Southamerica, Australia and New Zealand). Moderate endcmicity, 2-5% (South and Eastern Europe, North of Africa, Middle East, Soviet Union, Indian Subcontinent), High endcmicity: (Colombian Atlantic coast, Santanderes, Guainia, Vaupcs, Amazonas). Epidemic outbreaks have been described in the Venezuelan border (Yucpa Indians) with very high mortality in the young population, also in the Colombian Sierra Nevada, Urabá and Amazonas. The treatment of this form of hepatitis is very difficult and most of the patients evolves to liver failure despite the use of Interferon and more recently trisodic Phosphonophormato. Liver transplantation has been used with good results, however most of the surviving patients developed infection of the new graft. The Hepatitis B vaccine prevents this type of hepatitis.