RT Book, Section A1 Ryan, Kenneth J. SR Print(0) ID 1148673000 T1 Persistent Viral Infections of the Central Nervous System T2 Sherris Medical Microbiology, 7e YR 2017 FD 2017 PB McGraw-Hill Education PP New York, NY SN 9781259859809 LK accessbiomedicalscience.mhmedical.com/content.aspx?aid=1148673000 RD 2024/10/09 AB OverviewPersistent viral infections are those in which termination of early symptoms and disease is not accompanied by elimination of the virus from the host, but by persistence of viral genetic material in the host. Persistent viral infections could be latent infection, in which viral genome must be maintained without making any infectious virus particles or chronic infection, where low level of virus is made without causing any or little damage to the target tissue. Three main conditions must be fulfilled for a virus to cause persistent infection, including little to no cytopathic effect of the virus to the host cells, maintenance of viral genome in the host cell and avoid elimination by the immune system. Several viruses have utilized these strategies to persist in an immune-privileged site, the central nervous system, and over time after reactivation cause rare disease in the CNS or distant sites. These viruses include measles, rubella, enterovirus, HIV, JCV, HSV 1, 2, and VZV. In addition, nonconventional agents such as prions (infectious prion proteins, PrPsc) also cause slow degenerative diseases of the CNS such as Creutzfeldt-Jakob disease (CJD) and others. These persistent viral agents and prions and the diseases they cause will be discussed in this chapter.