Herpes B virus

Herpes simian B virus (Macacine herpesvirus 1 (formerly Cercopithecine herpesvirus 1, CHV-1), Herpesvirus simiae, B virus) is the endemic simplexvirus of macaque monkeys. B virus is an alphaherpesvirus, which consists of a subset of herpes viruses that travel within hosts using the peripheral nerves. As such, this neurotropic virus is not found in the blood.

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 central nervous system disease, resulting in permanent neurological dysfunction or death. Severity of the disease increases for untreated patients, with a case fatality rate of approximately 80%. Early diagnosis and subsequent treatment are crucial to human survival of 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 in 1997 when researcher Elizabeth Griffin was splashed in the eye at Yerkes National Primate Research Center. Proper personal protective equipment is essential when working with macaques, especially those animals that have tested positive for the virus. Bites, scratches and exposures to mucous membranes, including the eye, must be cleaned immediately.

Parvovirus B19

Primate erythroparvovirus 1, generally referred to as B19 virus, parvovirus B19 or sometimes erythrovirus B19, was the first (and until 2005 the only) known human virus in the family Parvoviridae, genus Erythroparvovirus; it measures only 23–26 nm in diameter. The name is derived from Latin, parvum meaning small, reflecting the fact that B19 ranks among the smallest DNA viruses. B19 virus is most known for causing disease in the pediatric population; however, it can also affect adults. It is the classic cause of the childhood rash called fifth disease or erythema infectiosum, or "slapped cheek syndrome."

The virus was discovered by chance in 1975 by Australian virologist Yvonne Cossart. It gained its name because it was discovered in well B19 of a large series of microtiter plates labelled in this way.

Virology

Erythroviruses belong to the Parvoviridae family of small DNA viruses. It is a non-enveloped, icosahedral virus that contains a single-stranded linear DNA genome. Approximately equal proportions of DNA of positive and negative sense are found in separate particles. At each end of the DNA molecule there are palindromic sequences which form "hairpin" loops. The hairpin at the 3' end serves as a primer for the DNA polymerase. It is classified as erythrovirus because of its capability to invade red blood cell precursors in the bone marrow. Three genotypes (with subtypes) have been recognised.