Forget the plague, this is the disease that will kill us all

Prion diseases arise when misfolded proteins trigger normal proteins to adopt the same abnormal shape, creating a self-propagating chain reaction that damages the brain. The piece emphasizes their disturbing features: long symptom-free incubation, difficulty detecting them before symptoms, resistance to ordinary sterilization, and no established cure. Once illness appears, it can progress over months to dementia, personality changes, movement problems and other severe neurological symptoms, ending in death. Human cases are rare - about one per million in developed countries - and most occur spontaneously, with a smaller share inherited or acquired through infection. Diagnosis is difficult during life and may rely on symptoms and indirect test results.

Past outbreaks show both the danger and limits of transmission. Mad cow disease spread through contaminated feed in Britain, prompting mass culling and food controls; the suspected human form, variant CJD, has caused 233 reported cases worldwide. Chronic wasting disease has spread widely among deer and related animals, persisting in soil, but there is no evidence it has infected people. Kuru, transmitted through funeral cannibalism in Papua New Guinea, ended after the practice stopped. The piece warns that engineered prions could pose a far greater threat if made more transmissible, and argues for pathogen surveillance, controls on biological materials and AI-assisted design, and stronger international bans on bioweapons. It also notes that human trials are beginning for a treatment intended to reduce production of the prion protein.