Monkey B virus is a herpes virus that mainly affects macaque monkeys but in rare cases can be transmitted to humans and cause serious illness
Monkey B virus (also called simian B virus, herpesvirus B, H simiae, or simply the B virus) is a type of herpes virus that mainly infects macaque monkeys.
Although monkey B virus infection in humans is rare, it can cause severe neurologic disease or fatal swelling of the brain and spinal cord (acute disseminated encephalomyelitis) if not treated early.
There have been only 50 human cases of monkey B virus infection since the virus was first identified in 1932. Of these, 21 died. Most infections were caused when a person was bitten or scratched by an infected monkey, or when broken skin was exposed to infected tissue or fluids. In 1997, a researcher died from monkey B virus infection after the body fluid of an infected monkey splashed into her eye.
However, not all exposures result in infections. Hundreds of incidents of bites and scratches occur in monkey facilities each year in the United States, yet infection is rare.
How does the monkey B virus infect humans?
Most macaques housed in primate facilities get infected with the monkey B virus by the time they reach adulthood. Although many stay asymptomatic or have mild symptoms, they can still spread the infection. It is therefore not advisable to keep macaque monkeys as pets. Shedding of the virus is further increased when the infected monkey is stressed or has a weakened immunity.
Monkey B virus infection can occur from:
- Bite or scratch from an infected monkey
- Contact with the monkey’s bodily substances (saliva, urine, feces) through the eyes, nose, mouth, or broken skin
- Cut from a contaminated syringe or cage (the virus can survive for hours on object surfaces, especially moist surfaces)
- Exposure to the brain (especially), spinal cord, or skull of an infected monkey
- Exposure to simian tissue cultures of the virus in labs
Only one case of human-to-human transmission of the monkey B virus has been documented so far.
What are symptoms of monkey B virus infection?
Symptoms of monkey B virus infection typically start within 1 month of exposure, although they may appear as early as 3-7 days after infection. You may notice flu-like symptoms including:
Other symptoms include:
- Pain, itching, or small blisters near the wound
- Difficulty breathing
- Difficulty swallowing
- Locked jaw
- Sensitivity to light or vision problems
- Confusion or unconsciousness
- Paresis (partial paralysis)
What should you do if you have been exposed to the monkey B virus?
If you are scratched or bitten by a macaque, wash the area well with soap, detergent, or iodine for 15 minutes. Keep rinsing with water for another 15-20 minutes.
Seek medical attention immediately and tell your healthcare provider that you have been exposed to a macaque that may be infected.