Causative agent
B virus (also known as herpes simiae virus) is a type of herpes virus that is usually found among macaques, a type of wild monkeys commonly found in Hong Kong. B virus is naturally carried in the saliva, urine and stool of macaques. Most infected macaques are usually asymptomatic or having mild disease.
Human infection of B virus is rare, with about 50 people documented to have been infected globally since 1932. Human infection has been reported in United States, Canada, Mainland China and Japan, and were mainly caused by bites or scratches by monkeys.
Clinical features
Infected persons may initially present with flu-like symptoms, such as fever and chills, muscle ache, fatigue and headache. Vesicular skin lesions may then occur at the bite or scratch site. As disease progresses, the virus can spread to the central nervous system resulting in pain/numbness/itchiness near the wound, problems with muscle coordination, damage to the nervous system and even death.
Mode of transmission
Human infections are mainly caused by bites or scratches by infected monkeys, while human-to-human transmissions are very rare.
Incubation period
Symptoms usually occur within 1 month of the patient being exposed.
Management
Human infection requires professional medical management.
Prevention
To minimise risk of acquiring B virus, members of the public are advised to note the following:
Members of the public may also visit website of the Agriculture, Fisheries and Conservation Department for more information on do's and don'ts when encountering monkeys: www.afcd.gov.hk/english/conservation/con_fau/con_fau_nui/con_fau_nui_str/con_fau_nui_str.html