The Centre for Health Protection and the Hospital Authority are monitoring a 23-year-old man showing symptoms of variant Creutzfeldt-Jakob Disease.

The man was born in the United Kingdom and came back to Hong Kong in early April. He was admitted to Kwong Wah Hospital on April 6, suffering from dizziness and exhibiting odd behaviour.

The man has clinical features suggestive of Creutzfeldt-Jakob disease - which is also known as mad-cow disease. But a number of laboratory tests have been negative, so the case has not been confirmed.

He is now being treated at Prince of Wales Hospital and is in critical condition. Concerned hospitals have adopted infection-control measures.

According to his relatives, he had no history of surgery, blood transfusion nor blood donation.