The Centre for Health Protection today said it recorded the first human case of B virus, also known as the herpes simiae virus, and urged the public to refrain from touching or feeding wild monkeys to minimise the risk of contracting the virus.

The centre is investigating the case, which involves a 37-year-old man with good past health, who had contact with wild monkeys and was wounded by them during a visit to Kam Shan Country Park in late February.

The man was admitted to Yan Chai Hospital through the accident and emergency department on March 21 with a fever and decreased conscious level. He is receiving treatment at the hospital’s Intensive Care Unit and is in a critical condition.

The man's cerebrospinal fluid specimen tested positive for B virus by the centre's laboratory today.

While this is the first case recorded in Hong Kong, the centre said cases were reported in other places such as the US, Canada, the Mainland and Japan, and were mainly caused by monkey bites or scratches, adding that human-to-human transmission is very rare.

It also explained that the B virus is naturally carried in the saliva, urine and stool of macaques - a type of wild monkey commonly found in Hong Kong. An infected person may initially present with flu-like symptoms that may progress to infection of the central nervous system.

The centre urged people to stay away from wild monkeys and wash any wounds caused by them with running water and seek medical attention immediately.