Chapter 1, Problem 1EDCS

Emerging Disease Case Study Variant Creutzfeldt-Jakob Disease

Ellen screamed obscenities as she staggered from the room and collapsed in the hallway, jerking uncontrollably and unable to stand. Her parents were shocked that their kind, considerate, and lovable daughter had changed so drastically during the past year. Sadly, she couldn’t even remember her siblings· names.

Ellen had joined the nearly 200 Europeans and one Canadian afflicted with variant Creutzfeldt-Jakob disease (vCJD; what the media call “mad cow disease” because most humans with the condition acquired the pathogen from eating infected beef). Because vCJD affects the brain by slowly eroding nervous tissue and leaving the brain full of spongelike holes. the signs and symptoms of vCJD are neurological. Ellen’s disease started with insomnia. depression. and confusion. but eventually it led to uncontrollable emotional and verbal outbursts, inability to coordinate movements, coma, and death. Typically, the disease lasts about a year, and there is no treatment.

Variant CJD resembles the rare genetic disorder Creutzfeldt-Jakob disease (named for its discoverers), which is caused by a mutation and occurs in the elderly. The difference is that the variant form of CJD results from an acquired infection and often strikes and kills college-aged people, like Ellen in our story. For more about vCJD, see pp. 398-400.

1. 1. The vCJD pathogen is primarily transmitted when a person or animal consumes nervous tissue (brains). How could cattle become infected?
2. 2. Why is vCJD called variant?
3. 3. What effect does this pathogen have on cattle?