how do humans acquire creutzfeldt-jakob disease or any prion disorders?
k3nz3n
people from papua new guinea obtained a strain of TSE, and some have obtained it from cows that are infected with mad cow disease. it can also be transmitted by blood transfusion. any other examples in which how humans obtain them? or better yet, how do they appear?
This is still not a science that is all that well understood, even if it is really cool. The two you mention seem to be the primary methods. What triggers the prions in the first place is not all that well understood but it appears that ingesting or taking up something that may have intact proteins already somehow alters, or they get altered and thus the prions wreak the havoc that results in creutzfeldt-jakob disease. One could surmise that eating anything that is a source of prions could potentially cause this, although ingesting deer with chronic wasting disease, for instance does not seem to trigger this.
By far the most common (but still rare):
Creutzfeld Jakob Disease (CJD) can be hereditary–the usual example is an hereditary disease most common in Sepharidic (particularly Libyan) Jews. This is known as familial CJD. Close to 15% of all cases are hereditary.
Or sporadic CJD–the result of a spontaneous gene mutation or perhaps just sponeous conversion of the prion protein to the misfolded, aggregated state. 85% of all cases.
The above two sources kill about 5000 people per year in the United States. Last I heard only one American had developed the disease originating with mad cow disease (vCJD), a woman who used to live in the UK.
Rare:
Cannibalism I believe is where it was first observed–the disease is called Kuru, the tribe is the Fore of Papua New Guinea. People caught it from eating the brains of cannibalism victims.
And of course mad cow disease (vCJD in humans)–by eating cows (or potentially other animals). Not all the cow–just the brain or spinal tissue. Obviously this is more common in the UK at the moment, although I understand the number of cases is dropping.
Other potential sources of transmission include such things as neurosurgery, corneal grafts and hormone injections. Also by reuse of surgical equipment.
All of these situations lead to proteins that are misfolded and aggregated, can propagate themselves and are infectious. The aggregated proteins are insoluble and accumulate, killing brain cells.
Many of the mutations in the prion protein leading to
CJD are known. See the second reference.
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