Taiwan authorities tested 21 monkeys captured from the wild and nine from a zoo in the southern city of Kaohsiung after reports of tourists being attacked by monkeys.

No injuries or death have been reported from the attacks on tourists in Taiwan, but concerns have been raised as Hong Kong is home to the same type of monkeys, which are not shy.

At least 1,500 macaques live in Hong Kong, most in the Kowloon hills, Shing Mun and Tai Po Kau, the Agriculture, Fisheries and Conservation Department said.

About 65 percent are rhesus macaques, 2 percent are longtailed macaques and the rest are hybrids resulting from cross breeding of the two.

Department acting director Lau Sin-pang did not rule out the possibility of monkeys in Hong Kong contracting B-virus, and said the department will test animals for the virus.

``Although the monkey species in Taiwan and Hong Kong are different, it is possible for monkeys in Hong Kong to carry the [B-virus],'' he said Monday.

``If there is a report of a human being being bitten, we will catch some monkeys for specific tests. Otherwise, our routine inspections are sufficient for surveillance.''

Controller of the Center for Health Protection Leung Pak-yin warned the public not to contact wild animals because, in addition to B-virus, they may also carry other harmful bacteria or viruses

B-virus, or cercopithecine herpesvirus 1, is virtually harmless to monkeys but can be deadly to humans. According to the US Centers for Disease Control, infection can result in a fatal encephalomyelitis, a general term for inflammation of the brain and spinal cord.

While B-virus disease in humans is extremely rare, an estimated 80 percent of untreated patients die of complications associated with the infection.

Most cases of human B-virus infection have involved direct contact with macaques - the most common family of monkeys in Asia.

In 1997, a 22-year-old female worker at a US primate center died from B-virus infection 42 days after being splashed in the eye by ``biologic'' material from a rhesus macaque.

CDC research suggests that B-virus from rhesus macaques may be more pathogenic for humans than B-virus from other macaque species.

The infection's incubation period lasts from a few days to a week. The disease often starts with general influenza-like symptoms of fever, muscle aches, fatigue and headache. Other variable symptoms include nausea, vomiting and abdominal pain.

Neurologic signs develop when the virus spreads to the central nervous system, and vary depending on the part of the brain or spinal cord affected.

Symptoms include over-sensitivity, blurred vision, confusion, urinary retention and difficulty in swallowing.

If the virus spreads to the central nervous system, chances of survival drop dramatically.

Even with antiviral therapy and supportive care, survivors suffer serious neurologic damage.

Bite wounds, scratches, or puncture wounds of nonmucosal surfaces should be cleansed with soap or detergent for at least 15 minutes, or at least rinsed under running water for 15 minutes.