The strand-specific qRT-PCR was performed as previously described by Freitas et al. (2012) . Briefly, the genomic and antigenomic RNAs were reverse transcribed separately with strand-specific primers into cDNAs: primer HDV398R (5′-CGCTTCGGTCTCCTCTAACT-3′) for genomic RNA; primer HDV288F (5′-GCAGACAAATCACCTCCAGA-3′) for antigenomic RNA. The reverse transcribed cDNAs of genmomic or antigenmoic HDV RNAs were used as templates for real-time PCR using the HDV398R and HDV288F primer pair. TaqMan probe was 5′ FAM-AGAGCTCTGACGCGCGAGGAGTAAGC-TAMRA 3′. Real-time PCR assays were conducted with an ABI Fast 7500 real-time PCR instrument.