A South Korean woman died of the brain-wasting Creutzfeldt-Jakob disease in July this year, becoming the first confirmed victim of the terminal disorder in the country, health authorities said Tuesday. The 54-year-old was diagnosed with iatrogenic Creutzfeldt-Jakob disease (iCJD) after her death and is believed to have been infected during brain surgery some 23 years ago, according to the Center for Disease Control (KCDC) and Prof. Kim Yun-joon, a professor at Hallym University\'s collage of medicine. Kim determined after conducting an autopsy that brain tissue from a cow used in the surgery to treat tumor growth infected her with the degenerative neurological disorder. Some 400 iCJD cases have so far been reported in 20 countries. This form of the ailment is usually transmitted by humans through operations and leaves the brain with holes that resemble a sponge. \"A detailed analysis of her brain showed the development of defective prion proteins,\" Kim said. \"A tissue graft product called Lyodura used in the operation may have been contaminated.\" This form of Creutzfeldt-Jakob disease has an incubation period of more than 20 years but once symptoms occur, death usually takes place within a year with most victims being 55 to 65 years of age. The deceased, whose identity has not been made public, started to complain of paralysis in the face in 2010, according to Kim. CJD is the most common of human prion diseases with one person in every 1 million diagnosed each year worldwide. It is an invariably fatal illness with death occurring after the rapid onset of dementia, hallucinations, coordination dysfunction and seizures. Related to the latest confirmation, the KCDC said it is tracking all Lyodura used around 1987 and checking patients that received it in surgery, since the risk of prion was not fully understood at the time. Health authorities, however, said graft products that are on the market now have all been designed from the outset so they cannot transmit the disease to patients. \"Products used in brain surgery are perfectly safe,\" said Park Hye-kyung, a disease control expert at the KCDC. The official stressed that despite concerns, iCJD is not connected with variant CJD, the human form of mad cow disease, that may be brought on by eating the meat of diseased animals. The government, meanwhile, said there may be a need to better regulate the widespread harvesting of brain tissue from the deceased to make certain that this type of disease does not spread. Both human and animal brain tissue are used in many types of surgery to treat neurological disorders.