Mad Cow desease is the colloquial name for Bovine spongiform encephalopathy (BSE), an incurable and fatal neurodegenerative disease of cattle that causes them to act abnormally.
In the United Kingdom, from 1986 to 2015, more than 184,000 cattle were diagnosed with BSE. It is believed that meat from several million cattle with the condition likely entered the food supply during the outbreak.
Spread to humans it is believed to result in variant Creutzfeldt–Jakob disease (vCJD) after eating food contaminated with it, particularly the brain, spinal cord, or digestive tract.
For the past 31 years, the University of Edinburgh has carried out a surveillance project around CJD.
The project’s latest annual report said since May 1995, 178 cases of definite or probable variant CJD (vCJD) had been identified in the UK. All 178 cases have died.
“Previous analysis of vCJD diagnoses and deaths from January 1994 indicated that the peak has passed,” the report said.
“While this is an encouraging finding, the incidence of vCJD may increase again, particularly if further cases in different genetic subgroups with longer incubation periods exist.”
It also noted the identification in 2003 of a case of vCJD associated with blood transfusion and the identification in 2004 of disease-related PrP (Platelet-Rich Plasma) in the spleen of a recipient of blood donated by someone incubating vCJD. A patient was also identified in 2010 who had evidence of vCJD infection in the spleen (but no evidence of clinical vCJD), considered probably due to blood products (treatment for haemophilia).
Overall, four instances of probable transfusion-transmitted infection have identified in three cases of vCJD and pre-clinical infection in a recipient with post-mortem confirmation of abnormal prion protein deposition in the spleen.
“There have been no new cases of transfusion-associated vCJD since 2007,” the report said.
“Results from all other types of CJD included in the project have not, so far, shown any evidence of transfusion transmission.”