Which of the following diseases is caused by a prion?

Bovine spongiform encephalopathy (BSE), commonly known as mad cow disease, is caused by prions, which are misfolded proteins that lead to neurodegenerative diseases. Prions can trigger abnormal folding of specific normal cellular proteins found in the brain, leading to brain damage and characteristic symptoms associated with prion diseases.

Unlike conventional infectious agents such as bacteria or viruses, prions lack nucleic acids and cannot be inactivated by typical sterilization methods, raising significant challenges in their study and management.

Other diseases listed, such as rabies, HIV/AIDS, and hepatitis B, are caused by viruses. Rabies is a viral infection that affects the nervous system and is typically transmitted through bites from infected animals. HIV/AIDS is caused by the human immunodeficiency virus, which attacks the immune system, while hepatitis B is a viral infection that affects the liver. Each of these diseases involves traditional viral replication processes, distinctly different from the mechanism of prion propagation and disease causation. Hence, only BSE is associated with prion infection.