Scientists have identified a previously unknown species of circovirus, provisionally named human circovirus 1 (HCirV-1). Circoviruses are a family of small, highly resistant DNA viruses that were initially identified in 1974 in various animal species, where they can cause respiratory, renal, dermatological and reproductive problems. HCirV-1 is a novel virus that is distant from known animal circoviruses. It was shown to be implicated in damage to the liver of a patient undergoing immunosuppressive treatment.