CDC monitors the occurrence of<unk>  in the United States through periodic reviews of national mortality data. According to the CDC: *<unk>  occurs worldwide at a rate of about 1 case per million population per year. * On the basis of mortality surveillance from 1979 to 1994, the annual incidence of<unk>  remained stable at approximately 1 case per million people in the United States. * In the United States,<unk>  deaths among people younger than 30 years of age are extremely rare (fewer than five deaths per billion per year). * The disease is found most frequently in people 55–65 years of age, but cases can occur in people older than 90 years and younger than 55 years of age. * In more than 85% of cases, the duration of<unk>  is less than one year (median: four months) after the onset of symptoms. Further information from the CDC: * Risk of developing<unk>  increases with age. *<unk>  incidence was 3.5 cases per million among those over 50 years of age between 1979 and 2017. * Approximately 85% of<unk>  cases are sporadic and 10-15% of<unk>  cases are due to inherited mutations of the prion protein gene. *<unk>  deaths and age-adjusted death rate in the United States indicate an increasing trend in the number of deaths between 1979 and 2017. Although not fully understood, additional information suggests that<unk>  rates in African American and nonwhite groups are lower than in whites. While the mean onset is approximately 67 years of age, cases of sCJD have been reported as young as 17 years and over 80 years of age. Mental capabilities rapidly deteriorate and the average amount of time from onset of symptoms to death is 7 to 9 months. According to a 2020 systematic review on the international epidemiology of<unk> : * Surveillance studies from 2005 and later show the estimated global incidence is 1–2 cases per million population per year. * Sporadic<unk>  (sCJD) incidence increased from the years 1990–2018 in the UK. * Probable or definite sCJD deaths also increased from the years 1996–2018 in twelve additional countries. *<unk>  incidence is greatest in those over the age of 55 years old, with an average age of 67 years old. The intensity of<unk>  surveillance increases the number of reported cases, often in countries where<unk>  epidemics have occurred in the past and where surveillance resources are greatest. An increase in surveillance and reporting of<unk>  is most likely in response to BSE and vCJD. Possible factors contributing to an increase of<unk>  incidence are an aging population, population increase, clinician awareness, and more accurate diagnostic methods. Since<unk>  symptoms are similar to other neurological conditions, it is also possible that<unk>  is mistaken for stroke, acute nephropathy, general dementia, and hyperparathyroidism.
Creutzfeldt–Jakob disease
Anti-Hu associated encephalitis
Powassan encephalitis
Kuru (disease)  Kuru  1
Saint Louis encephalitis
Variant Creutzfeldt–Jakob disease  Variant Creutzfeldt–Jakob disease  1
Autoimmune encephalitis
Viliuisk encephalomyelitis