Microbiology

                                                     Prion disease


        A group of conditions that affect the nervous system in humans and animals. All are currently untreatable and universally fatal. 
         
        In people, these conditions impair brain function, causing changes in memory, personality, and behavior, dementia, and abnormal movements and ataxia.

        It is very rare and the conditions affects one person per million worldwide each year. Approximately 350 new cases are reported annually in the United States.

          A Prion is an infectious agents and specifically a protein in a misfolded form. Prion protein (PrP) are responsible for mammalian transmissible spongiform encephalopathies, including bovine spongiform encephalopathy and scrapie in sheep. In humans, cause Creutzfeldt - Jakob disease (CJD), variant Creutzfeldt - Jakob disease (vCJD), Gerstmann–Sträussler–Scheinker syndrome, Fatal Familial Insomnia and kuru.

       Prions are not considered living organisms but are misfolded protein molecules.  If a prion enters a healthy organism, it induces existing, properly folded proteins to convert into the disease-associated, misfolded prion form; the prion acts as a template to guide the misfolding of more proteins into prion form. These newly formed prions can then go on to convert more proteins themselves; as a result; produces large amounts of the prion form. This altered structure is stable and are resistant to denaturation by chemical and physical agents; as a result; accumulates in infected tissue, causing tissue damage and cell death.