Acute
Hepatitis D (HDV) is caused by the hepatitis D virus, also known as delta virus or delta agent. It can affect the liver in a variety of ways and can lead to fulminant liver failure. Hepatitis D virus is a defective RNA virus requiring hepatitis B surface antigen (HBsAg) for pathogenicity (allows binding to hepatocytes and virion assembly). Thus HDV can be acquired simultaneously with hepatitis B (HBV) (co-infection) or in a previously HBsAg positive individual (super-infection). Co-infection with both HDV and HBV at the same time is associated with a more severe clinical outcome compared with HBV infection alone. Super-infection occurs when a chronically HBV-infected individual contracts HDV. Fifteen million of 350 million HBV patients are also infected with HDV.
HDV is transmitted most commonly through blood or blood products, though transmission can also occur by sexual contact, and much less commonly through vertical transmission. Recent studies have shown the highest prevalence of HDV transmission in patients ages 21-40 and have suggested sexual contact may be a more common route of transmission in this population than previously thought. Higher prevalence rates additionally occur in the Mediterranean regions, central / western Africa, northern Asia, Vietnam, and Amazonian areas. While rates of HDV were previously thought to be decreasing in North America and Europe, recent trends show increasing prevalence and highlight the need for screening HDV-negative individuals as well as counseling HDV-positive individuals for sexual transmission prevention.
Clinically, HDV infection may present asymptomatically, with symptoms of acute hepatitis, or with worsening of previously asymptomatic HBV infections. Signs and symptoms of HDV infection are nonspecific to this virus and include jaundice, pruritus, anorexia, fatigue, abdominal distention and ascites, and encephalopathy. Patients may also complain of dark-colored urine or pale stools.
Physical examination may reveal lowered blood pressure, yellow skin discoloration, spider angiomata, abdominal distention and ascites, hepatosplenomegaly, palmar erythema, Muehrcke nails, and Terry nails.
Immunocompromised Patient Considerations:
A substantially more aggressive progression of HDV may be associated with triple infection with HIV and HBV, and screening for HDV is recommended for HIV+ / HBV+ patients.
Codes
ICD10CM: B17.8 – Other specified acute viral hepatitis
