Spongiform encephalopathies have been reported in a variety of large and small mammals.1 While conducting a study of Creutzfeldt-Jakob disease (CJD) in south Florida, one of us (JRB) observed an affected patient who was originally a native of Kentucky and had a history of eating squirrel brains. Dietary transmission of prion diseases has been documented experimentally in animals2 and in human beings who are cannibals.3 Several case reports have suggested the possibility of transmission of CJD by consumption of brains of wild animals.4 These observations, together with recent concerns about the transmission of a unique encephalopathy in man believed to be related to bovine spongiform encephalopathy5 led us to examine the possible association of eating squirrel brains with CJD in rural Kentucky, where eating squirrel and other small game is not uncommon.
Culinary preparations include scrambling the brains with eggs or putting them in a meat and vegetable stew referred to as "burgoo". A history of eating squirrel brains was obtained from family members of all five patients with probable or definite CJD seen over 3,5 years in a neurocognitive clinic in western Kentucky. Two women and three men aged from 56 to 78 years (mean 68.2 years) were affected. None were related and each lived in a different town. Eating squirrel brains was reported among 12 of 42 patients with Parkinson's disease seen in the same clinic and 27 of 100 age-matched controls without neurological disease living in western Kentucky. Ataxia early in the course of the disease was seen in four of the patients with CJD and myoclonus and periodic complexes on the electroencephalogram were seen in all.
Death occurred within 1 year in four, whereas, survival exceeded 3 years from the onset of symptoms in one patient. Analysis of codon 129 of the prion protein gene was not done. This observation will require confirmation by studies of larger populations, and a search for a scrapie agent in the brains of squirrels, which have not heretofore been reported as having spongiform encephalopathies. In the meantime caution might be exercised in the ingestion of this arboreal rodent.
1 Prusiner SB. Genetic and infectious prion diseases. Arch Neurol 1993; 50: 1129�53.
2 Gibbs DJ Jr, Amyx HL, Bacote A, Masters C, Gajdusek DC. Oral transmission of kuru, Creutzfeldt-Jakob disease, and scrapie to nonhuman primates. J Infect Dis 1980; 142: 205�08.
3 Gajdusek DC. Unconventional viruses and the origin and disappearance of kuru. Science 1977; 197: 943�60.
4 Kamin M, Patten BM. Creutzfeldt-Jakob disease: possible transmission to humans by consumption of wild animal brains. Am J Med 1984; 76: 142�45. 5 Will RG, Ironside JW, Ziedler M, et al. A new variant of Creutzfeldt-Jakob disease in the UK. Lancet 1996; 347: 921�25.