Which coinfection increases mortality in chronic hepatitis B carriers?

• A. Hepatitis D
• B. Hepatitis A
• C. Hepatitis C
• D. HIV

Answer: (A)

In chronic hepatitis B carriers, certain coinfections dramatically worsen liver disease, and the most impactful is hepatitis D virus. HDV is a defective RNA virus that cannot replicate without the hepatitis B surface antigen, so it only occurs in people with HBV. When HDV superinfects someone who already has chronic HBV, the liver inflammation is typically more severe, disease progression to cirrhosis happens faster, and the risk of fulminant hepatitis and death increases. Vaccination against HBV blocks HDV infection by removing the HBV substrate, which is why HBV vaccination programs help prevent this deadly combination. Hepatitis A usually causes an acute, self-limited illness and does not create a chronic carrier state that raises mortality in chronic HBV patients. Hepatitis C can complicate liver disease but is not the classic coinfection that uniquely increases mortality in chronic HBV. HIV coinfection can worsen overall health and treatment complexity, but the association most emphasized with higher mortality in chronic HBV is HDV coinfection.