The document discusses several hepatitis viruses: 1. Hepatitis D virus (HDV) requires hepatitis B virus (HBV) for transmission and can cause either simultaneous (coinfection) or superinfection in those with chronic HBV. Superinfection usually results in persistent HDV infection. 2. Hepatitis E virus (HEV) is a non-enveloped RNA virus transmitted via the fecal-oral route. It typically causes self-limiting infection without progression to chronic illness. 3. Hepatitis G virus (HGV), also known as GB virus C, is an enveloped RNA virus that often co-infects with hepatitis C virus, hepatitis B virus, and HIV.