Final answer:
Creutzfeldt-Jakob disease is often misdiagnosed because it is rare, has symptoms similar to other diseases, has a long incubation period, and is caused by prions that are difficult to detect and diagnose.
Step-by-step explanation:
The most likely reason that many cases of Creutzfeldt-Jakob disease (CJD) go undiagnosed each year is that it is an extremely rare disease, and its symptoms can be similar to those of other neurodegenerative disorders. CJD is caused by prions, which are misfolded proteins that induce normal proteins to also misfold, leading to rapid degeneration of brain tissue. These prions are transmissible and can result in diseases like mad cow disease in cows and CJD in humans.
Furthermore, due to the variety of symptoms and the extensive incubation period of the disease, which can span years or decades, diagnosis is challenging. The brain degeneration caused by prions is characterized by sponge-like lesions, but these symptoms often appear only in later stages of the disease, and death typically occurs within months to a few years after symptoms become apparent. Diagnosis can be further complicated by the lack of genetic material within prions, making them difficult to detect and categorize using standard microbial diagnostic methods.