PERSISTENT VIRAL INFECTIONS - best known ones that affect...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
PERSISTENT VIRAL INFECTIONS This term refers to a viral infection that occurs gradually over a long period of time. The virus is  gradually building up over a long period of time, and in most cases eventually will be fatal. These  infections can also be called slow viral infections. An example is that very rarely, years after  causing a normal case of measles, the virus remains in the body and eventually causes a rare  form of encephalitis.     PRIONS These are strange infectious agents which appear to be proteins. The first disease identified to be  of this type was scrapie of sheep in 1982. There are now nine animal diseases in this category,  including mad cow disease in Great Britain. All of them are neurological diseases causing the  development of large vacuoles in the brain, and can be called spongiform encephalopathies. The 
Background image of page 1
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: best known ones that affect humans are kuru and Creutzfeldt-Jakob disease. These diseases seem to run in families, which may indicate a genetic component, but they also can be transmitted from person to person. Somehow these prions, which appear to be pure protein with no nucleic acid involved, may change a normal gene found in brain cells to an abnormal form. Exactly how this takes place or even exactly how the damage occurs is not yet understood. One theory is that the prion enters and attaches to a normal protein and changes its shape. They the newly changed abnormal protein attaches to other normal proteins and changes their shape--on and on....
View Full Document

This note was uploaded on 01/23/2012 for the course MCB MCB2010 taught by Professor Smith during the Fall '09 term at Broward College.

Ask a homework question - tutors are online