November 2011, the Korean Center for Disease Control determined that a 54-year-old woman, who died earlier this year, died of iatrogenic Creutzfeldt-Jakob disease (CJD). After her death, doctors identified several defective prion proteins in her brain, signaling the presence of CJD.
This week, a second individual (identity withheld for privacy reasons) was diagnosed with iatrogenic CJD.
Both cases underwent brain surgery 23 years ago. During each surgery, a product called Lyodura was used for tissue grafting purposes. Lyrodura is often made of human dura mater, or the outermost of the membranes covering the brain and spinal cord, which is acquired post mortem. Officials believe this product may have been contaminated.
CJD is extremely rare, occurring in approximately one out of one million people. It is caused by a prion protein, that causes other proteins to fold abnormally, thus interfering with the normal protein functions. It has an incubation period that can last a few decades. Symptoms typically begin after one reaches age 50 and may include dementia, hallucinations, lack of coordination, personality changes and speech impairment. This rare disease has no treatment and is fatal.
There are different forms of CJD: classic and variant. Classic CJD can occur sporadically, for no apparent reason, or through genetic inheritance. Variant CJD (vCJD), however, is a rare form of the prion disease. Variant CJD is often caused by the transfusion or transplant of contaminated biological products, such as in the cases in South Korea.
The Korean CDC is tracking all cases that underwent procedures using Lyodura and contemplating regulations surrounding the use of brain tissue from the deceased for transplants.
Other prion diseases include bovine spongiform encephalitis (BSE or ‘mad cow disease’), chronic wasting disease (found in deer), scrapie (found in sheep) and kuru, a nervous system disease found in brain tissue. Kuru is found in certain peoples of New Guinea, who practiced funeral rites that including ingesting the brain tissue of the deceased. The practice stopped in 1960, but the disease continued to be recorded many years later due to its long incubation period.