Health Ministry to make statement on potential CJD case

2.30pm

Medical authorities say they will make an announcement later today on the man who may have New Zealand's first case of variant creutzfeldt-jakob disease (vCJD).

An invariably fatal brain-wasting disease, vCJD is thought to be caused by eating meat or meat products from cattle infected with madcow disease (bovine spongiform encephalopathy, or BSE).

The Health Ministry announced eight days ago it was awaiting results of tests on a 26-year-old farm worker to see if he had vCJD.

"Ordinary" CJD, alzheimer's or other brain diseases were also a possible diagnosis for the man, who was in a stable condition in a general ward at Waikato Hospital in Hamilton.

Paul Timmings, the man's neurologist, said two samples from the man -- spinal fluid and a tonsil -- had been sent to Australia for testing in addition to other tests.

Results of the fluid were expected this week and the tonsil results next week.

The fluid test for vCJD is at best suggestive and the tonsil test has high rates of false positives and false negatives. Dr Timmings said the false negative rate was 25 to 30 per cent.

"It is possible the diagnosis might simply change from possible to probable."

Once all the tests had been completed, the man may be able to go home.

The ministry revealed the man's illness on August 8 because it was under pressure from trade and agriculture sectors to dispel mistaken reports from Britain of a foot-and-mouth disease outbreak in New Zealand.

New Zealand has never had foot-and-mouth disease or BSE in its cattle.

More than 133 people have contracted vCJD in Britain, where the median age of patients at death is 28. It often starts with depression and progressively affects movement and memory. Patients generally survive for 14 months from diagnosis.

Food safety officials have said that if the man in Hamilton does have the disease, he would have contracted it years ago from food containing British beef products made with tissue from an infected cow's central nervous system.

New Zealand banned imports of potentially risky beef or beef products from Britain in 1996.

- NZPA