This led to the product being banned in Canada but it was used in other countries such as Japan until 1993.A review article published in 1979 indicated that 25 dura mater cases had occurred by that date in Australia, Canada, Germany, Italy, Japan, New Zealand, Spain, the United Kingdom, and the United States.By 1985, a series of case reports in the United States showed that when injected, cadaver-extracted pituitary human growth hormone could transmit CJD to humans.In 1992, it was recognized that human gonadotropin administered by injection could also transmit CJD from person to person.Stanley B. Prusiner of the University of California, San Francisco (UCSF) was awarded the Nobel Prize in Physiology or Medicine in 1997 "for his discovery of Prions—a new biological principle of infection".Yale University neuropathologist Laura Manuelidis has challenged the prion protein (PrP) explanation for the disease. In January 2007, she and her colleagues reported that they had found a virus-like particle in naturally and experimentally infected animals. "The high infectivity of comparable, isolated virus-like particles that show no intrinsic PrP by antibody labeling, combined with their loss of infectivity when nucleic acid–protein complexes are disrupted, make it likely that these 25-nm particles are the causal TSE virions". Australia
Australia has documented 10 cases of healthcare-acquired CJD (iatrogenic or ICJD). Five of the deaths resulted after the patients, who were in treatment either for infertility or short stature, were treated using contaminated pituitary extract hormone but no new cases have been noted since 1991.
Transmission
The defective protein can be transmitted by contaminated harvested human brain products, corneal grafts, dural grafts, or electrode implants and human growth hormone.It can be familial (fCJD); or it may appear without clear risk factors (sporadic form: sCJD). In the familial form, a mutation has occurred in the gene for PrP, PRNP, in that family. All types of CJD are transmissible irrespective of how they occur in the person.It is thought that humans can contract the variant form of the disease by eating food from animals infected with bovine spongiform encephalopathy (BSE), the bovine form of TSE also known as mad cow disease. However, it can also cause sCJD in some cases.Cannibalism has also been implicated as a transmission mechanism for abnormal prions, causing the disease known as kuru, once found primarily among women and children of the Fore people in Papua New Guinea, who previously engaged in funerary cannibalism. While the men of the tribe ate the muscle tissue of the deceased, women and children consumed other parts, such as the brain, and were more likely than men to contract kuru from infected tissue.Prions, the infectious agent of CJD, may not be inactivated by means of routine surgical instrument sterilization procedures. The World Health Organization and the US Centers for Disease Control and Prevention recommend that instrumentation used in such cases be immediately destroyed after use; short of destruction, it is recommended that heat and chemical decontamination be used in combination to process instruments that come in contact with high-infectivity tissues.