Chronic Hepatitis D Virus (HDV) Infection in Hepatitis B Virus Carrier Chimpanzees Experimentally Superinfected with HDV

Abstract

Chimpanzees that were chronic hepatitis B virus carriers and that were superinfected with hepatitis D virus (HDV) apparently developed acute, self-limited type D hepatitis. Reevaluation with a sensitive hybridization-based assay using RNA probes specific for the HDV genome, however, demonstrated that >50% of these animals still had detectable signs of ongoing HDV replication an average of 2.4 y (range, 1–6.4 y) after inoculation. The only positive marker for the presence of HDV was serum HDV RNA; HDV antigen was undetectable in both serum and the liver by an immunoblot assay and immunofluorescence, respectively. Because the detected amount of viral genome was very low, the previous failure to identify the chronic HDV carrier state in the chimpanzee can be attributed to the lower sensitivity of previously described assays.