<unk>  is predominantly a blood-borne virus, with very low risk of sexual or vertical transmission. Because of this mode of spread the key groups at risk are intravenous drug users (IDUs), recipients of blood products and sometimes patients on haemodialysis.<unk> ommon setting for transmission of<unk>  is also intra-hospital (nosocomial) transmission, when practices of hygiene and sterilization are not<unk> orrectly followed in the<unk> linic. A number of<unk> ultural or ritual practices have been proposed as a potential historical mode of spread for<unk> , including<unk> ircumcision, genital mutilation, ritual scarification, traditional tattooing and acupuncture. It has also been argued that given the extremely prolonged periods of persistence of<unk>  in humans, even very low and undetectable rates of mechanical transmission via biting insects may be sufficient to maintain endemic infection in the tropics, where people receive large number of insect bites.
Hepatitis C virus
Hepatitis B virus
Hepatitis F virus
Influenza B virus
Dhori virus
Rubella virus
Hendra virus
Human T-lymphotropic virus 2