Snapshot A 35-year-old man presents to the emergency department for nausea, malaise, fatigue, and abdominal pain. He says that his abdominal pain is in the right upper quadrant and is not associated with meals. Medical history is significant for HIV infection. He intravenously injects himself with heroin and reports to sharing needles. Physical examination is notable for right upper quadrant tenderness and scleral icterus. Laboratory testing is remarkable for a marked transaminitis. Serology demonstrates the presence of HBsAg and HDAg. Introduction Classification an RNA hepevirus Microbiology transmission fecal-oral properties contains a helical nucleocapsid uses hepatitis B virus envelope (HBsAg) in order to cause infection Epidemiology risk factors hepatitis B co-infection Associated conditions co-infection with hepatitis B causes an acute hepatitis antibodies against HBsAg are protective superinfection causes acute hepatitis in a patient with chronic hepatitis B infection Presentation Symptoms anorexia nausea right upper quadrant pain Physical exam jaundice and scleral icterus Studies Serologic studies HBsAg needed to make the diagnosis since hepatitis D virus (HDV) requires hepatitis B virus envelope HDAg seen in acute infection anti-HDV seen in chronic infection IgM anti-HBc suggests co-infection of hepatitis B and D viruses Differential Hepatitis A infection differentiating factor presence of anti-hepatitis A antibodies in serological testing Hepatitis B infection differentiating factor presence of anti-hepatitis B antibodies in serological testing Hepatitis C infection differentiating factor presence of anti-hepatitis C antibodies in serological testing Treatment Medical pegylated interferon α (IFNα) indication seen in patients with elevated HDV RNA levels and active hepatitis note, there is no treatment for acute HDV infection Complications Acute fulminant hepatic failure Cirrhosis Hepatocellular carcinoma