Detection of antibodies against domestic cat hepadnavirus using baculovirus-expressed core protein

A novel orthohepadnavirus (domestic cat hepadnavirus [DCH]) similar to human hepatitis B virus has been recently detected in serum and liver samples from domestic cats with chronic hepatitis and hepatocellular carcinoma. Molecular investigations by independent research groups around the world have revealed positivity rates ranging from 6.5% to 12.5% in blood samples and up to 14.0% in liver tissue. In this study, we screened an age-stratified collection of feline sera (n = 256) by using an antibody detection enzyme-linked immunosorbent assay based on the recombinant core antigen of DCH (DCHc). Specific antibodies (DCHc Abs) were detected with a prevalence of 25.0%. The DNA of DCH was detected in 35.9% (23/64) of seropositive cats and only in 1.0% (2/192) of seronegative animals. Based on the serological (IgG and IgM anti-DCHc) and virological status, the possible stages of DCH infection were predicted.