North American Veterinary Licensing Examination (NAVLE) Practice Test

The connection between variant Creutzfeldt-Jakob disease (vCJD) in humans and bovine spongiform encephalopathy (BSE) is well established. BSE, commonly known as "mad cow disease," is a neurodegenerative disease of cattle that is caused by prions—misfolded proteins that can induce other proteins to misfold similarly, leading to brain damage. The agent of BSE can be transmitted to humans through the consumption of infected beef products, resulting in vCJD, which is a human form of the disease characterized by rapidly progressive dementia and other neurological symptoms.

Understanding this relationship is crucial, as it highlights the importance of monitoring and controlling BSE to prevent its transmission to humans. The other options mentioned do not have a direct association with vCJD: sporadic bovine encephalomyelitis does not exist as a recognized condition, while equine West Nile virus encephalitis and Eastern equine encephalomyelitis are viral diseases affecting horses and are unrelated to prion diseases. Thus, bovine spongiform encephalopathy is the only option that correctly identifies the source linked to the variant form of Creutzfeldt-Jakob disease in humans.