Workshop

PART D– Post workshop activity
Q1. What is the name of this disease? Describe some of the symptoms and brain pathologies.
The name of the disease is Kuru. Kuru is an incurable and life-threatening disease that is witnessed in tribal population of Papua New Guinea. It is a type of spongiform encephalopathy that is highly contagious and could be easily transmitted from one individual to another. Kuru is a degenerative neurological disorder that is caused by prions originating in humans. The word is derived from the word “kuria,” which indicates shaking. Kuru is featured by tremors in the body. Body tremors are classical symptoms of the disease. Kuru develops from funerary cannibalism. The disease is commonly witnessed in the “Fore tribe” of Papua New Guinea. The different symptoms of the disease are truncal ataxia, which is featured by headaches, pains in the joint and trembling in limbs. The incubation period is usually 5 to 20 years. The initial symptoms are unstable gait, dysarthria and muscle tremors. As the disease proceeds, the patient has difficulty in walking and suffers from ataxia. The individual suffers from depressive disorders and uncontrolled laughter. In the final stage, the patient suffers from dysphagia and severe ataxia. The disease originates from prions and is strongly related to Creutzfeldt-Jacob disease (CJD).

Q2. What is the causative agent of this disease? Why is no immune response observed in patient’s suffering this disease?
The disease originates from prions in human beings, and the disease is strongly related to Creutzfeldt-Jacob disease (CJD).

Studies have indicated that an individual fails to develop sufficient immunity from this disease. As a result, individuals affected with Kuru are highly immune-compromised. Therefore, the risk of pneumonia and life-threatening infections are very high in individuals, who are affected by Kuru. Research has indicated that individuals suffering from Kuru are carriers of a genetic variant of prion –resistant protein. This prion resistant protein is designated as G127V. The protein is thought to be genetically transferred from one generation to another. Natural selection plays a strong role in the hereditability of the protein. The presence of the resistant form of the prion protein is responsible for the decreased immune responses that are witnessed in individuals suffering from Kuru.

Q3. What is the current opinion on where and how this disease developed?
Kuru disease was first witnessed in individuals belonging to the Fore tribe of Papua New Guinea. These tribes resided in the eastern regions of Papua New Guinea. The disease was first discovered during 1953 and 1959 when Australian administrators explored this area. The disease was first reported by W.T. Brown in 1954. The disease caused a pandemic in the South Fore of the Okapa subdistrict. The disease develops from mortuary cannibalism. It develops from the brain tissues of the corpus that is fed by the individuals affected by Kuru disease. The disease develops due to encephalopathy in the brain.

Q4.What was one of the key pieces of information about the make-up of the family unit that helped
discount the theory of genetic inheritance? Who was the researcher that recognized this?
The practice of mortuary cannibalism is more prevalent in women and children. On the other hand, males believed that consumption of corpus would weaken them. The researcher was Shirley Lindenbaum.

Q5. What condition in animals was first identified as having the same characteristics to the human disease? How did this discovery help unravel the mystery of the human disease?
Chimpanzees were the first animals who presented the same characteristics to the human variant of the disease. In 1976, Gadjusek and Bloomberg indicated that Kuru was transmissible to chimpanzees. Kuru was the first incidences of encephalopathy that were classified as infectious. Moreover, Kuru is the only example of an epidemic that occurs due to prions present in humans. The discovery of Kuru disease has provided important information for unraveling the pathophysiology of Bovine spongiform encephalopathy and Creutzfeldt-Jacob disease (CJD).

Q6. How does this case highlight strong arguments for both the use and prevention of research involving non-human primates?
This observation will help to unfold the different domains of Bovine spongiform encephalopathy and Creutzfeldt-Jacob disease (CJD). On the other hand, experimentation with Chimpanzees would lead to increased transmission rates of the disease.

Q7. A decline in the incidence of Kuru correlated with the cessation of what social practice? How did this finding help explain the dimorphism of Kuru between men and women of the tribe?
The decline in Kuru was associated with the cessation of mortuary cannibalism. The sexual dimorphism related to the prevalence of Kuru is strongly evident. The prevalence of Kuru in women and children are 8 to 9 times more compared to males. This is because the male population belonging to the Fore tribe believed that consumption of corpus would weaken them in the battlefield.

Q8. Inter-species transmission of a similar prion disease has been shown. Indicate what disease has been transmitted and what it gives rise to in humans. How was this disease transmitted to humans?
Inter-species transmission of similar prion diseases is Bovine spongiform encephalopathy and Creutzfeldt-Jacob disease (CJD). The diseases are Bovine spongiform encephalopathy and Creutzfeldt-Jacob disease (CJD). The diseases are transmitted through consumption of corpus and occur due to acts of mortuary cannibalism.

Q9. What is known about the incubation period of this disease? What can this tell us about new cases of variant CJD in the future?
The incubation period is usually 5 to 20 years.
Studies have compared the transmission properties of Kuru prions with prions of CJD. These variants of CJD are either iatrogenic or sporadic. The studies were conducted on Prnp-null transgenic mice that expressed the human prion protein in wild-type mice. The molecular and pathophysiological properties indicated that the Kuru prion variants were distinct from the prions that were responsible for different variants of CJD. However, it was also noted that the transmission properties of Kuru prions were similar to the transmission of classical (sporadic) CJD prions. The results signified that Kuru disease originated from chance consumption of sporadic CJD.

Q10.Two Nobel prizes have been awarded for work in this area. Who were the recipients and on what grounds where they awarded?
The Nobel prizes were awarded to Gajdusek and Bloomberg in a field of Physiology and Medicine. The Nobel prize was awarded in 1976. The Nobel prize was awarded as they were the first individuals to indicate that Kuru disease is transmissible to chimpanzees and provided insights into the pathophysiology of Bovine spongioform encephalopathy and Creutzfeldt-Jacob disease (CJD). Another Nobel prize was awarded to Kurt Wuthrich for determining the structure of the prion protein responsible for the development of Kuru.