No new risk to NZers in British sheep scare
No new risk to New Zealanders in British sheep scare
SUGGESTIONS that British sheep and lambs could carry a form of CJD have few implications for New Zealanders because our precautions against the disease are amongst the best in the world, the Ministry of Health says.
"Our blood supply - theoretically the most likely route of infection - is one of the safest in the world, we have had a ban on British beef products in place since 1996, our sheep-feeding practices are different and the amount of British sheepmeat coming into New Zealand is miniscule," Chief Medical Adviser Dr Colin Feek said.
"New Zealanders, including those who have spent time in the United Kingdom, need have no greater fear about their risk of contracting variant Creutzfeldt Jakob Disease.
"It is worth noting that to date there is NO evidence that New Zealanders travelling to the UK, even those who have eaten beef while travelling, have become infected with vCJD."
Overnight reports from the United Kingdom say authorities are drawing up contingency plans in case BSE - bovine spongiform encephalitis - has spread from cows to sheep flocks.
Although there is no evidence that this has happened British authorities are considering the possibility as they investigate deaths from variant Creutzfeldt Jakob Disease in a Yorkshire village.
Dr Feek said New Zealand's blood supply was well-protected against variant CJD.
"We have a ban on blood donation from people who spent more than six months in the United Kingdom between 1980-1996. This takes in people who have eaten any sort of meat.
"The New Zealand Blood Service is also implementing a new filtering process - leucodepletion - which removes white blood cells prior to transfusion. "Prions", the infective agents of vCJD, are closely linked with white blood cells," Dr Feek said.
Dr Feek said there had ban on British beef and beef products since 1996, when the British outbreak of variant CJD was first publicised.
"The 1996 outbreak also prompted new guidelines to hospitals and health services on infection control during procedures such as autopsies, neurosurgery and opthalmology, and on sterilisation of instruments. "
Dr Feek said the BSE science panel in NZ had already discussed whether or not the ban on beef imports should be extended to sheep.
"That there is a theoretical risk from sheepmeat is not new. Bear in mind that British authorities are stressing that there is no evidence to suggest theory has become reality. Rather they are investigating to see whether there is any evidence, and at the same time looking at contingency plans should that be the case."
Dr Feek said the Ministry was seeking information on British sheepmeat imports but preliminary advice was that the amount is miniscule.
"We have also checked with MAF about sheep-feeding practices in New Zealand. There is a legislative ban on feeding ruminants to ruminants. This formalises a voluntary ban which we are advised was widely observed," Dr Feek said.
For more information contact:
Frances Ross Chief media advisor Tel: 496 2202/025 512 833
Creutzfeldt-Jakob Disease is a rare fatal brain disorder which was first recognised more than 70 years ago. There is no effective treatment and no reliable test to predict the disease. Approximately 85 percent of Creutzfeldt-Jakob Disease illnesses occur spontaneously without any known cause. Other causes include certain medical treatments that are no longer used such as human growth hormone injections, dural grafts (brain membrane). The symptoms may take 30 years to develop. Since the disease was identified by Dr. Alfons Maria Jakob in the 1920's, over 3,000 cases have been reported world-wide.
Variant Creutzfeldt-Jakob Disease (vCJD) is a new and more aggressive strain of the disease which was identified in the United Kingdom in 1996. It produces similar symptoms to classical CJD though the disease develops more rapidly. Variant CJD is thought to be contracted by eating meat infected with bovine spongiform encephalitis (BSE) which has been described as "mad cow disease". It historically has affected people in the 16 to 52 year age group. The mean age is 28 years.
CJD tends to affect people aged from 60+ and symptoms may take 30 years to develop, whereas vCJD has been found in teenagers and young adults and it develops more rapidly. A striking early feature of vCJD is prominent psychiatric disturbance.
Since 1980 approximately two to three cases of Creutzfeldt-Jakob Disease have been identified in New Zealand each year. This figure represents approximately one case per million people per year - the expected rate seen internationally. There have been no cases of vCJD in New Zealand.
In 1996 CJD was made a notifiable disease and a case register for CJD established. The register is similar to those already operating in Australia and the United Kingdom. This means all cases of CJD are notified so that cases can be reviewed and investigated to ensure consistent diagnosis and risk factor identification.
Leucodepletion is a filtering process which removes white blood cells prior to transfusion. "Prions", the infective agents of vCJD, are closely linked with white blood cells. Removing them will further reduce the "theoretical" risk of vCJD transmission. Leucodepletion will cost approximately $8-million per year. Introduction of leucodepletion will be a gradual staged process.
Leucodepletion removes certain viruses, is likely to reduce the risk of bacterial infections such as Yersinia, and reduces the likelihood of adverse reactions to transfusion. Some evidence suggests leucodepletion will reduce the rate of post-operative infection.
Further Questions and Answers
Is there a test for vCJD? Not yet. Overseas work continues on this but a test maybe years away.
Is the Ministry aware of anyone within New Zealand who has travelled to the UK and become infected with vCJD? No. The Ministry does not believe that people who have travelled to the UK should be concerned about their health. To date, there is no evidence that travellers to the UK, even those who may have eaten beef while travelling there, have become infected with vCJD.
Frances Ross Chief Media Advisor Communications DDI: 496 2202 Fax: 496 2010 mailto:firstname.lastname@example.org Ministry of Health