Genotypes of Hepatitis B and D Viruses Among Patients With Hepatitis D in the United States.

The epidemiological landscape of paired hepatitis B virus (HBV)/hepatitis delta virus (HDV) genotype (GT) among patients with HDV in the US remains unknown. HBV/HDV genotypes were assessed in two independent US cohorts: Cohort 1 included 5222 HBV-positive patients from Quest Diagnostics, including 114 anti-HDV+ patients; Cohort 2 included 178 anti-HDV+ samples from highly phenotyped patients managed at the National Institutes of Health (NIH). HBV/HDV sequencing and genotyping were analysed using phylogenetic analyses. In the overall cohort, HBV and HDV genotypes were determined for 197 (67%) and 139 (48%) patients, respectively, with HDV GT1 and GT5 and paired HBV/HDV genotypes D/1 and A/1 being the most prevalent. The most frequent HBV genotypes were GTD (40%) and GTA (35%), and the most frequent HDV genotypes were GT1 (84%) and GT5 (13%). Among 111 paired HBV/HDV genotypes, D/1 (50%) and A/1 (26%) were most common. In Cohort 2, 77 (79%) patients with HDV GT1 were foreign-born, most commonly Mongolian-born (47/77, 61%), while 21% (20/77) were US-born. Among patients with HDV GT5, GT6, or GT7, 93% (14/15) were of African origin. Overall, these findings provide the first comprehensive US analysis of HBV/HDV paired genotypes among patients with HDV and indicate that HBV genotype distributions differ between HBV/HDV coinfection and HBV monoinfection.