Slow virus
A slow virus is a virus, or a viruslike agent, etiologically associated with a slow virus disease. A slow virus disease is a disease that, after an extended period of latency, follows a slow, progressive course spanning months to years, frequently involves the central nervous system, and in most cases progresses to death. Examples of slow virus diseases include HIV/AIDS, caused by the HIV virus, subacute sclerosing panencephalitis, the rare result of a measles virus infection, and Paget's disease of bone, which may be associated with paramyxoviruses, especially the measles virus and the human respiratory syncytial virus.
Characteristics
Every infectious agent is different, but in general, slow viruses:Additionally, the immune system seems to plays a limited role, or no role, in protection from many of these slow viruses. This may be due to the slow replication rates some of these agents exhibit, preexisting immunosuppression, or, in the case of prions, the identity of the agent involved.
Scope
Slow viruses cause a variety of diseases, including cancer.| Virus | Virus family | Disease | Typical latency | Transmitted by |
| JC virus | Polyomavirus | Progressive multifocal leukoencephalopathy | Years to Life§ | Unknown; possibly contaminated water |
| BK virus | Polyomavirus | BK nephropathy, bladder cancer | Years to life§ | Unknown; possibly respiratory spread/urine; possibly contaminated water |
| Measles virus | Paramyxovirus | Subacute sclerosing panencephalitis | 1–10 years | Respiratory droplets |
| Rubella virus | Togaviridae | Progressive rubella panencephalitis | 10–20 years | Respiratory droplets |
| Rabies virus | Rhabdoviridae | Rabies | 3–12 weeks | Bite of an infected animal |
| Human papillomavirus infection | Papillomaviridae | Cancers of the cervix, oropharynx, vulva, anal, penis, vagina and rectum. | Years | Sexual activity |