What is “MAD COW” Disease?

Variant CJD (vCJD) the human form of bovine spongiform encephalopathy (BSE) commonly known as “mad cow” disease has not occurred in Australia, although to date 229 cases have occurred worldwide, most in the UK.

vCJD was first recognised in 1996 in the UK after the first death occurred in England in 1995.

Variant CJD related to the consumption of bovine spongiform encephalopathy (BSE) contaminated meat products following the epidemic of BSE (a prion disease that occurs in cattle) during the 1980 and 1990s in the UK.

Variant CJD is often incorrectly referred to as ‘Mad Cow Disease’ by the media and has subsequently been used inappropriately in reference to all forms of CJD.

Is Variant CJD different to other forms of CJD?

Yes, vCJD is an acquired form of prion disease that is quite difference to the human form of CJD or classical CJD.

  • A predominantly psychiatric presentation
  • Younger age at onset – approx 28 years
  • Longer duration of illness – average 14 months
  • Different investigation results and distinctive pathological changes to the brain

See articles of interest – What is variant CJD and how does it differ from other forms of CJD?

What is Kuru?

Kuru is a human prion disease that was identified only in the central highlands of Papua New Guinea. People of of the Fore and closely linked tribes practiced endocannibalism, the eating of close relatives, as a mourning rite. These rituals were discouraged and outlawed by the late 1950s and correspondingly the numbers of recorded cases declined. Kuru has now almost disappeared.

Is CJD contagious?

There is no evidence that CJD can be transmitted through social contact, transmitted through the air or through any type of touching, drinking from the same cup, kissing or sexual intercourse.

How is CJD transmitted?

CJD can only be transmitted from one person to another through invasive medical procedures including cornea transplants or contaminated surgical instruments. In the 1980’s it was recognized that explanted material, such as human pituitary hormones for fertility or short statue, from dura mater grafts, accidentally contaminated with prion protein, could also transmit this disease to recipients.

vCJD may be transmitted to humans via the consumption of contaminated beef products and via blood transfusions in the UK.

Why am I deferred from donating blood if I have lived in UK for a total of six months during 1980 to 1996?

There is emerging evidence that vCJD,, the human form of bovine spongiform encephalopathy (BSE or “Mad Cow” Disease) can be transmitted via blood transfusion. People who have spent six months or more in the UK during the BSE risk period of 1980–1986 have been deferred from donating blood in Australia. This has now been extended to include people who have received a transfusion or injection of blood products in the UK since 1980.

Why am I deferred from donating blood if a first degree family member has died of CJD?

The Red Cross Blood Service has no way of knowing if your relative died of sporadic CJD or a familial or inherited form of CJD.

Although there is no evidence that CJD is transmitted via blood in CJD cases there is no way to prove it is not. The blood banks of Australia currently defer anyone from donating blood who is at risk of CJD. This includes people who have a family history of inherited CJD.

For family members, where genetic CJD has not been ruled out by a negative result from prion protein gene (PRNP) testing for the individual family member, they are assumed to be at increased risk by the Australian Red Cross Blood Service as a precaution only. If genetic CJD in the family has been ruled out by genetic testing on the index patient indicating sporadic CJD then those family members, although still deferred from donating blood, should not require special precautions for any medical procedures.

Note: An individual from a known genetic family who themselves has had a negative result from prion protein gene (PRNP) test will be accepted as a blood donor by the Australian Red Cross Blood Service.

Current infection control guidelines recommend deferral when there is a family history of two or more first degree relatives but the Red Cross Blood Service questionnaire defers all 1st and 2nd degree relatives of a CJD or suspected CJD patient.

Why am I deferred from donating blood if I have received human pituitary hormones prior to 1985 or dura mater grafts prior to 1990?

Although there is no proof that CJD can be transmitted by blood, there is insufficient proof that it cannot; hence those who are at increased risk of developing CJD in Australia, for example over 2000 people who were on the human pituitary program up until 1985 and people who have received dura mater grafts during neuro-surgery until 1989, have no way of knowing if they are incubating CJD. Therefore, people who have been identified as having an increased risk of developing CJD will continue to be deferred from donating blood and face screening questionnaires on CJD on admission forms in hospitals and other facilities.

Is CJD a notifiable disease in Australia?

In June 2004 the Communicable Diseases Network of Australia agreed to designate any TSE as a notifiable disease in Australia.