A 27-year-old man with a history of intravenous drug use is known to have been infected with the hepatitis B virus for the past 6 years and has not been ill. He is seen in the emergency department because he has had nausea, vomiting, and passage of dark-colored urine for the past week. Physical examination shows scleral icterus and mild jaundice. Neurologic examination shows a confused, somnolent man-oriented only to person. He exhibits asterixis. Laboratory studies show total protein, 5 g/dL; albumin, 2.7 g/dL; AST, 2342 U/L; ALT, 2150 U/L; alkaline phosphatase, 233 U/L; total bilirubin, 8.3 mg/dL; and direct bilirubin, 4.5 mg/dL. Superinfection with which of the following viruses has most likely occurred in this man?
HDV cannot replicate in the absence of HBV; isolated HDV infection does not occur. The evidence for chronic hepatitis B is the presence of HBsAg and anti-HBc IgG antibody in the absence of an anti-HBc IgM antibody. Confirmatory serologic evidence of recent HDV infection is the presence of anti-HDV IgM antibodies. HBV and HDV infections are likely to occur in drug users who inject parenterally. When HDV infection is superimposed on chronic HBV, three outcomes are possible: mild hepatitis B may be converted to fulminant disease; acute hepatitis may occur in an asymptomatic HBV carrier; or chronic progressive disease may develop, culminating in cirrhosis. The other listed viruses can cause infection by themselves.
HAV
HCV
HDV
HEV
Liver & Biliary Tract