Domestic cat hepadnavirus is detected infrequently in feline blood and liver samples submitted for diagnostic testing in Texas, USA.

Domestic cat hepadnavirus (DCH), a novel hepatitis B-like virus, has been detected in cats in several regions but data are fragmented. Investigation of DCH is driven by the societal role of cats as human companions, disease risk to sympatric endangered felids, as well as HBV medicine. This study investigated the molecular epidemiology and sequence diversity of DCH in diagnostic blood or non-paired liver samples submitted in Texas. Patient age, sex, breed, neuter status, and retrovirus serology results were recorded for risk factor analyses. Using qPCR, DCH DNA was amplified from 3/400 blood samples (0.8 % (95 % CI: 0.3-2.2 %) with virus loads of 4.06 × 10, 2.33 × 10, and 27.1 × 10 copies/μL of blood. Feline immunodeficiency virus and feline leukemia virus seroprevalence was 4.3 % (95 % CI: 2.5-7.1 %) and 7.5 % (95 % CI: 5.0-10.8 %), respectively. A low DCH detection rate precluded risk factor analysis. Among liver samples, DCH DNA was amplified by PCR from 4/303 (1.3 % (95 % CI: 0.4-3.4 %), one of which also tested positive by in situ hybridization. Phylogenetic analyses of 3 DCH genomes obtained in this study showed high homology to viruses in Genotype A with no evidence of geographic clustering. This study, only the second in the USA, contributes to data on the worldwide prevalence of DCH viremia and, in the context of accumulating data on this potential feline pathogen, supports that the prevalence of DCH viremia, may vary geographically, as described for hepatitis-B virus and woodchuck hepatitis virus.