Final answer:
CJD is a fatal neurodegenerative disease caused by prions with several transmission modes including eating contaminated meat, exposure to contaminated medical equipment, use of infected human tissue, and inherited genetic mutations.
Step-by-step explanation:
CJD, a fatal neurodegenerative disease caused by prions, has multiple modes of transmission. Most cases of CJD are sporadic, occurring without a known cause, but for those acquired, transmission can occur through:
- Eating contaminated meat from animals such as cattle affected by Bovine Spongiform Encephalopathy, commonly known as mad cow disease.
- Exposure to contaminated medical equipment, particularly instruments used in neurosurgery.
- Use of infected human growth hormone or corneas from donors with undiagnosed CJD.
- Inherited genetic mutations that predispose individuals to the disease.
Rare human-to-human transmission of variant CJD is associated with consumption of nervous tissue, as seen in kuru through ritualistic practices. However, there is no evidence for casual contact transmission of CJD.
Infectious diseases like CJD underscore the importance of accurate diagnosis, preventative measures such as sterilization of surgical tools, and avoiding the use of infected tissue. Immunizations are critical in controlling many infectious diseases, although no vaccine exists for prion diseases.