By: Jenny Dorth
B virus is also known as cercopithecine herpesvirus 1 and herpesvirus simiae and is a member of the herpes group of viruses that are enzootic in rhesus, cynomolgus, and other Asiatic monkeys.
This virus can be found in the blood, tissues, and secretions of these monkeys and it doesnít have a very severe pathogenesis in its natural monkey hostæ it usually causes a mild or inapparent disease such as conjunctivitis, gingivostomatitis, and genital ulcers. However, this virus can be potentially very dangerous if transmitted to a human because the pathogenesis in humans is much more severe. Infection can occur in people who work with monkeys, either in zoos or labs. The transmission event can be via a monkey bite, direct or indirect contact with saliva of an infected monkey. In some cases the virus might be aerosolized, and transmission has even been shown in cases of lab researchers working with monkey cell cultures.
The clinical course of disease is severe in humans. It begins with one of the transmission events described above and the outcome isnít good if the infection goes unrecognized and untreated as it has a 70% fatality rate in humans. An infected individual usually presents with localized redness, vesicles and may experience pain at the site of virus introduction. Clinical manifestations can be vesicles located on the mucous membranes, pneumonia, diarrhea, abdominal pain, pharyngitis, and lymphocytic pleocytosis.
If these clinical symptoms are left untreated, then B virus infection can be life-threatening as it can lead to fatal ascending myelitis and encephalopathy, having a 70% mortality rate. Survivors facing severe neurological damage. B virus is only handled in the laboratory under Bio Safety Level 4 conditions.
The incubation period of this infection is a few days to a month or longer, sometimes years. This is characteristic of herpes viruses that have the ability to lie latent.
Although this virus can result in very severe clinical manifestations, the transmission event is usually limited to that between monkeys and humans (with only one documented case of human-to-human transmission). If people who work with monkeys that are suspected of having B virus infection take proper precautions, then the incidence of this disease can be further lessened. As all monkey-inflicted injuries are preventable, special and standard procedures should be used in handling them. The most critical period for the prevention of infection is during the first few minutes after exposure. Thorough cleansing of the wound site can help to decrease the amount of virus that enters the bloodstream. It is likely that B virus can enter the bloodstream within 5 minutes of exposure, so the use of detergents to destroy the viral lipid envelope and to inactivate B viruses, followed by 15 minutes of scrubbing to wash away all virus should be done immediately. If mucosal surfaces have been exposed, they should be irrigated with water for 15 minutes.
After the initial infection and cleansing, patients and the monkey involved should be medically tested for B viral infection. If either of these medical examinations show that the monkey involved is shedding virus or if the human has symptoms, acyclovir antiviral prophylaxis treatment should be administered immediately. It is generally not recommended that persons awaiting medical tests receive acyclovir because the antiviral drug doesnít interrupt the early stage of B virus entry into the cell. Antiviral treatment can be administered a few days following possible exposure and then discontinued if the patient continues to be asymptomatic and if B virus wasnít cultured from the monkey. Acyclovir or ganciclovir antiviral treatment has been shown to be highly effective. The optimal duration and administration of the therapy is unknown.
Various vaccines have been developed and tested in animals, some even administered to humans, but none have been licensed for general, public use. The main method is that of prevention and post-exposure antiviral therapy.
This is a very severe disease when left untreated, so the individual that draws this card while playing Pathogenesis must shout out preventative measures within 30 seconds in order to avoid becoming infected and dying (being thrown out of the game).
What did the monkey say to the human? You'd best be watching or I'd be biting and you'd be getting B virus!