How common is new variant Creutzfeldt-Jakob (nvCJD) disease and how many people have been affected by BSE?
As mentioned above, there are many forms of transmissible spongiform encephalopathies (TSE), including all types of CJD, which is the most common form in humans. The Centers for Disease Control and Prevention (CDC) has monitored the trends and incidence of CJD for over the past 20 years by analyzing death certificate information. Only new variant Creutzfeldt-Jakob (nvCJD) has been associated with BSE, and as of February 2004, only one case of nvCJD has been identified in the U.S. This case occurred in a person who had grown up in the UK and moved to the U.S. as a teenager, and it was concluded his BSE contact occurred when he resided in the UK. Rare cases of non-BSE CJD are noted, which occurs for unknown reasons but may be related to genetic predisposition to the disease. The CDC has documented annual death rates from CJD between 1987 through 1998 as relatively constant at about one case per one million persons, and primarily in people well over the age of 30 years. Cases of CJD in in
