Three cases of the rare and fatal brain disease Creutzfeldt-Jakob disease (CJD) have emerged in Hood River County, Oregon—a statistically improbable cluster in a population of just 23,000, given the disease’s global incidence of one to two cases per million and only 350 cases annually in the U.S. Reported over the past eight months, one case is confirmed and two are probable; two individuals have died, and test results are pending for the third. CJD is caused by misfolded prion proteins that create sponge-like holes in the brain, leading to rapid neurological decline with symptoms such as confusion, hallucinations, and loss of coordination. Diagnosis typically involves microscopic examination of brain tissue. Health officials are investigating potential links between the cases while maintaining family privacy. 

Transmissible spongiform encephalopathies (also known as prion diseases) such as CJD can be transmitted by exposure to contaminated brain tissue, corneal grafts, pituitary growth hormone,   or improperly sterilized electrodes or surgical instruments that have come in contact with infected tissue. It can also appear spontaneously from a mutation to the gene encoding the major prion protein. Humans can contract the disease from eating food from animals infected with their own versions of prion disease, e.g. bovine spongiform encephalopathy (“mad cow disease”), scrapie in sheep, or CWD (chronic wasting disease) in deer and elk. Prions cannot be transmitted by air, water, or casual touching. Kristine de Leon via Oregon Live