How is transmission to humans thought to occur?

• A. Ingestion of infected cattle meat
• B. Inhalation of aerosols
• C. Bloodborne transmission
• D. Direct contact with brain tissue

Answer: (A)

Transmission to humans is thought to occur primarily through consuming beef products contaminated with prions concentrated in neural tissue. Prions are misfolded proteins that resist usual cooking and disinfection, so when infected meat is eaten, those abnormal proteins can interact with normal prion proteins in the body and trigger a cascade leading to neurodegenerative disease. While other routes like inhalation, blood exposure, or direct contact with brain tissue can be risks in specific settings (lab exposure, rare transfusion transmissions), they are not the common route by which the broader population would acquire the disease.