London, March 30 (IANS) Nearly 40 people in Britain are at risk of developing a fatal brain disease through infected medical instruments, a media report said.

CJD or Creutzfeldt-Jakob disease is a form of brain damage that leads to rapid decrease of mental function and movement.

It is believed to result from a protein called a "prion". A prion causes normal proteins to fold abnormally. This affects the other proteins' ability to function. The disorder is very rare, occurring in about one out of one million people.

Officials at the Abertawe Bro Morgannwg University Health Board in Wales found at least 38 people were at risk of developing the incurable brain condition, the Daily Express reported.

One patient first underwent surgery in 2007. The surgical instruments used in his surgery were reportedly used in 38 other operations, said a hospital spokesman.

Though the equipment was sterilised, it was not done at a "high enough" temperature to eradicate infectious proteins, he said.