HOSPITAL bosses have been unable to give patients more accurate information about their risk of contracting CJD despite a five-month wait for answers, it emerged last night.

The 24 patients, who all had brain surgery at Middlesbrough General Hospital in the summer, were told in October that they could have been infected by tainted surgical instruments.

It had been hoped to give them more information, but it has proved impossible to be more precise.

They were contacted when tests carried out in August showed that a female patient who underwent an exploratory brain operation in July had the sporadic form of CJD.

Patients were angry that they were not told about the matter until October.

The incident caused concern throughout the NHS because it suggested there may be gaps in infection control.

The patients were told that they had a low risk of developing the incurable brain disease because of fears that infectious prions might have survived cleaning processes.

It had been hoped that the patients could be given more accurate risk assessments by experts at the national CJD Surveillance Centre, in Edinburgh.

But last week, the patients were called in and told that it was impossible to be more specific.

One patient, a 38-year-old Darlington woman who asked to be known only as Mandy, said: "We had all this fuss about individual assessments being made but it turns out that it is impossible."

The patient, who underwent three brain operations last year and has been classified as low risk, added: "They kept us hanging on for months for these assessments which they can't do."

Mandy expressed concern that there was still no sign of the Department of Health's report into the CJD scare.

Dr Paul Lawler, medical director for the South Tees NHS Trust, said he could not comment on the risk assessment given to patients because of NHS confidentiality rules.

He apologised for the length of time it had taken to come up with new assessments.

Dr Lawler said sterilisation had been upgraded since the incident and procedures to keep track of instruments used for brain surgery have been in place since December.

He said: "I think the whole incident has identified important issues about the traceability of instruments."

A Department of Health spokeswoman said the report on the CJD incident on Teesside will be published shortly.