A 37-year-old man in critical condition after being attacked by monkeys in a Hong Kong country park has tested positive for B virus, marking the first case of the deadly infection in the city.

The man, who was admitted to the hospital for fever and decreased consciousness on March 21, is believed to have been wounded during a visit to Kam Shan Country Park, a popular hiking destination known for its troop of wild monkeys, in late February.

The Health Department has issued a warning to the public to avoid touching or feeding wild monkeys and urged anyone injured by monkeys to seek immediate medical attention. The B virus, carried in the saliva, urine, and stool of macaques, a type of wild monkey commonly found in Hong Kong, can cause severe brain damage or death if not treated promptly.

This marks the first case of the rare infection in Hong Kong, with previous instances of monkey bites or scratches leading to illness in the US, Canada, Japan, and mainland China. Human-to-human transmission of the virus, also known as the herpes simiae virus, is rare, according to health authorities.

The Centre for Health Protection emphasized that infected persons may initially present with flu-like symptoms that can progress to infection of the central nervous system. The authorities are currently investigating the case and advising the public to exercise caution around wild monkeys.