“The article reproduced recently in ProMed suggested that a US patient developed variant Creutzfeldt-Jakob disease (vCJD). This diagnosis was based on MRI results that reportedly appeared similar to those of patients with variant CJD (vCJD). However, all other clinical and demographic evidence (triphasic EEG pattern, patient age, disease duration, and subsequently prion protein codon 129 genotype) strongly suggested that this was a case of sporadic Creutzfeldt-Jakob disease (sCJD). Indeed, through national human prion disease surveillance, the patient was confirmed through autopsy as sCJD, not vCJD. The reporting of this case as probable vCJD – a disease linked to consumption of beef contaminated with bovine spongiform encephalopathy (BSE, also known as “mad cow disease”) – and suggesting that this case might be etiologically linked to squirrel consumption is inappropriate and may cause undue alarm.

“The previous ProMed commentary mentioned a 1997 Lancet report that hypothesized about a potential link between consumption of squirrel brains and CJD; there was no mention of vCJD in that report. Since that brief report, there has been no convincing evidence found suggesting that the consumption of squirrel meat, brain or otherwise, is a risk factor for any prion disease. While prion diseases have been identified in several other types of mammals, they have never been identified in squirrels. Without additional experimental or epidemiological evidence, a link between consumption of squirrel brain and human prion disease is unjustifiably speculative.”