Herpes B Virus

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Herpes B Virus

Herpes B virus (Cercopithecine herpesvirus 1, herpesvirus simiae, B virus) is the endemic simplexvirus of macaque monkeys. In the natural host, the virus exhibits pathogenesis similar to that of herpes simplex virus (HSV) in humans. Conversely, when humans are zoonotically infected with B virus, patients can present with severe CNS disease, resulting in permanent neurological dysfunction or death. Severity of the disease increases for untreated patients, with a mortality rate of approximately 80%. Early diagnosis and subsequent treatment are the lynchpins of surviving the infection.

Linked with more than two dozen deaths since its discovery, B virus is the only identified nonhuman primate herpesvirus that displays severe pathogenicity in humans. The last identified case of human B virus infection occurred in 2008, with the last known fatality occurring when a worker at the Yerkes National Primate Research Center was infected in 1997 after an eye splash occurred. Proper personal protective equipment is essential when working with macaques, especially those who have tested positive for the virus. Bites, scratches and exposures to mucous membranes, including the eye, must be cleaned immediately. Samples from both the macaque and human should be sent for B virus diagnostic testing as recommended by the B Virus Working Group here: BVIRUS.pdf

As of 2002, there had been 26 well-defined cases of human B virus infection, 16 of which lead to death. At least 20 of the patients developed some degree of encephalitis.

The History of B Virus

Herpes B virus was first identified in 1932 following the death of Dr. William Brebner, a young physician who was bitten by a monkey while researching the virus that causes poliomyelitis. Soon after, Brebner developed localized erythema, followed by lymphangitis, lymphadenitis and, ultimately, transverse myelitis. Neurologic tissues obtained during Dr. Brebner’s autopsy revealed the presence of an ultrafilterable agent that appeared similar to HSV in cell culture. This isolate was originally termed “W virus.”

Within a year of Brebner’s death, Dr. Albert Sabin identified an unfilterable agent from the same tissue, which he later named B virus. Sabin further described the lethality of B virus by showing that infectivity was independent of the route of inoculation. Additionally, it was observed that B virus induced immunologic responses similar to HSV-1 as well as shared similarities to HVP-2 and Langur herpesvirus, two other nonhuman primate alphaherpesviruses.()

By 1959, B virus was identified as the causative agent in 17 human cases, 12 of which resulted in death (). Approximately 50 cases had been identified by 2002, although only 26 were well documented. The latest identified case of B virus occurred in 2008, per the National B Virus Resource Center in Atlanta, GA.