Transmission of HDV is thought to be similar to that of HBV. It is mostly through blood and blood products. This makes the at-risk groups IV drug users, health care workers, and people who have received infected blood transfusions or blood products such as antihemophilic factor. Sexual transmission is also thought to be possible, although a less common method for HDV than it is for HBV or HIV.
HBV vaccination is effective against HDV so this is currently the best method to prevent infection. Since the methods of transmission are similar, practices designed to minimize the transmission of HBV, HCV, and HIV – especially among drug addicts – will also diminish the transmission of HDV.