A Novel Hepadnavirus Identified in an Immunocompromised Domestic Cat in Australia

Abstract

High-throughput transcriptome sequencing allows for the unbiased detection of viruses in host tissues. The application of this technique to immunosuppressed animals facilitates the detection of viruses that might otherwise be excluded or contained in immunocompetent individuals. To identify potential viral pathogens infecting domestic cats we performed high-throughput transcriptome sequencing of tissues from cats infected with feline immunodeficiency virus (FIV). A novel member of the Hepadnaviridae, tentatively named domestic cat hepadnavirus, was discovered in a lymphoma sample and its complete 3187 bp genome characterized. Phylogenetic analysis placed the domestic cat hepadnavirus as a divergent member of mammalian orthohepadnaviruses that exhibits no close relationship to any other virus. DNA extracted from whole blood from pet cats was positive for the novel hepadnavirus by PCR in 6 of 60 (10%) FIV-infected cats and 2 of 63 (3.2%) FIV-uninfected cats. The higher prevalence of hepadnavirus viraemia detected in FIV-infected cats mirrors that seen in human immunodeficiency virus-infected humans coinfected with hepatitis B virus. In summary, we report the first hepadnavirus infection in a carnivore and the first in a companion animal. The natural history, epidemiology and pathogenic potential of domestic cat hepadnavirus merits additional investigation.

Discovery of a highly divergent hepadnavirus in shrews from China

“…However, the SHBV identified in this study were from shrews captured in China (Old World) and fell as a sister group to TBHBV in the genome phylogeny. This argues against a New World origin, as does the very deep phylogenetic position of the newly identified cat hepadnavirus identified in Australia (Aghazadeh et al, 2018). Moreover, SHBV was discovered in multiple shrew species and at more than one sampling site (two distant sampling sites, > 1200 km), indicating that SHBV has likely been present in these animals for an extended time period.…”

“…Similarly, bats comprise around 20% of living mammalian species and are also natural hepadnavirus reservoirs (He et al, 2013Drexler et al, 2013;Wang et al, 2017a;Nie et al, 2018). Although a divergent orthohepadnavirus was recently identified in domestic cats (cat hepadnavirus, CHV) (Aghazadeh et al, 2018), the only other mammalian species that appear to be natural hosts of orthohepadnavirus are primates, including divergent viruses present in the woolly monkey (WMHBV) (Lanford et al, 1998;Rasche et al, 2016) and capuchin monkey (CMHBV) (de Carvalho Dominguez Souza et al, 2018). Importantly, a phylogenetically distinct virus harboured by tent-making bats (TBHBV) has the ability to infect human hepatocytes (Drexler et al, 2013).…”

Evolutionary biology of human hepatitis viruses

“…[25][26][27][28][29] HBV-related viruses were detected in bats during 2013-2015 30,31 and in a domestic cat in 2018. 32 A distinct HBV species termed capuchin monkey hepatitis B virus (CMHBV) was described in 2018. 33 Endogenous and exogenous viruses distantly related to HBV were detected in reptiles, fish and amphibians.…”

“…Transmission routes for other bat or cat hepadnaviruses remain unknown. 30,32 HCV is a blood-borne virus. However, perinatal transmission rates are much lower for HCV than HBV and sexual transmission is rare.…”

Metagenomics revealing new virus species in farm and pet animals and aquaculture

“…The type species, human hepatitis B virus (HBV), is a major public health problem, and an estimated 257 million people are currently living with HBV. A new feline hepadnavirus was retrieved in a virus discovery project in Australia (Aghazadeh et al, 2018) from a domestic cat presented with multicentric, large cell, high-grade, B-cell lymphoma, and infected with FIV. A molecular survey for hepadnavirus revealed the presence of the novel hepadnavirus in the blood of 6/60 (10%) FIV-infected cats and two out of 63 (3.2%) uninfected cats.…”