''Alcelaphine gammaherpesvirus 2'' (AlHV-2) is a species of ''

Macavirus ''Macavirus'' is a genus of viruses in the order ''Herpesvirales'', in the family ''Herpesviridae'', in the subfamily ''Gammaherpesvirinae''. Mammals serve as natural hosts. There are nine species in this genus. Diseases associated with this gen ...

'' that is believed to be responsible for causing

hartebeest The hartebeest (; ''Alcelaphus buselaphus''), also known as kongoni or kaama, is an African antelope. It is the only member of the genus ''Alcelaphus''. Eight subspecies have been described, including two sometimes considered to be indepen ...

infections of

malignant catarrhal fever Bovine malignant catarrhal fever (BMCF) is a fatal lymphoproliferative disease caused by a group of ruminant gamma herpes viruses including ''Alcelaphine gammaherpesvirus 1'' (AlHV-1) and ''Ovine gammaherpesvirus 2'' (OvHV-2) These viruses cause ...

Clinical definition

Distantly related to human

herpes Herpes simplex is a viral infection caused by the herpes simplex virus. Infections are categorized based on the part of the body infected. Oral herpes involves the face or mouth. It may result in small blisters in groups often called cold s ...

, a virus of this type is composed of a series of double strand sequences of up to 100

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

segments, aligned along a long

chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...

surrounded by terminal DNA segments. The effect of the virus is to cause nasal discharge, a high fever, filmed over eyes, failures of the

lymphatic system The lymphatic system, or lymphoid system, is an organ system in vertebrates that is part of the immune system, and complementary to the circulatory system. It consists of a large network of lymphatic vessels, lymph nodes, lymphatic or lymphoid o ...

, inflammation of various

mucous membrane A mucous membrane or mucosa is a membrane that lines various cavities in the body of an organism and covers the surface of internal organs. It consists of one or more layers of epithelial cells overlying a layer of loose connective tissue. It is ...

s, and occasionally

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. Necrosis is caused by factors external to the cell or tissue, such as infection, or trauma which result in the unregulated dige ...

of the upper

digestive system The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion (the tongue, salivary glands, pancreas, liver, and gallbladder). Digestion involves the breakdown of food into smaller and smaller compone ...

. Very advanced cases show signs of decay of the

nervous system In biology, the nervous system is the highly complex part of an animal that coordinates its actions and sensory information by transmitting signals to and from different parts of its body. The nervous system detects environmental changes th ...

. Occasionally, lesions,

arthritis Arthritis is a term often used to mean any disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, swelling, and decreased range of motion of the affected joints. In som ...

, and digestive problems such as diarrhea have been observed.

Cause

The agent of MCF in hartebeests, it is related to other variants that strike down

antelopes The term antelope is used to refer to many species of even-toed ruminant that are indigenous to various regions in Africa and Eurasia. Antelope comprise a wastebasket taxon defined as any of numerous Old World grazing and browsing hoofed mammal ...

. It was isolated in 1960 and is believed to be carried as reservoirs by

goats The goat or domestic goat (''Capra hircus'') is a domesticated species of Caprinae, goat-antelope typically kept as livestock. It was domesticated from the wild goat (''C. aegagrus'') of Southwest Asia and Eastern Europe. The goat is a membe ...

sheep Sheep or domestic sheep (''Ovis aries'') are domesticated, ruminant mammals typically kept as livestock. Although the term ''sheep'' can apply to other species in the genus ''Ovis'', in everyday usage it almost always refers to domesticated s ...

, and other

domestic animals This page gives a list of domesticated animals, also including a list of animals which are or may be currently undergoing the process of domestication and animals that have an extensive relationship with humans beyond simple predation. This includ ...

. There are variants that have affected

deer Deer or true deer are hoofed ruminant mammals forming the family Cervidae. The two main groups of deer are the Cervinae, including the muntjac, the elk (wapiti), the red deer, and the fallow deer; and the Capreolinae, including the reindeer ...

gnu GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...

, and other captive species in zoos around the world.

Range

All species of African

wildebeest Wildebeest ( , , ), also called gnu ( or ), are antelopes of the genus ''Connochaetes'' and native to Eastern and Southern Africa. They belong to the family Bovidae, which includes true antelopes, cattle, goats, sheep, and other even-toe ...

and hartbeest can be infected or at least carry this virus. There is no

direct evidence Direct evidence supports the truth of an assertion (in criminal law, an assertion of guilt or of innocence) directly, i.e., without an intervening inference. A witness relates what they directly experienced, usually by sight or hearing, but also p ...

that other African wild variants like

addax The addax (''Addax nasomaculatus''), also known as the white antelope and the screwhorn antelope, is an antelope native to the Sahara Desert. The only member of the genus ''Addax'', it was first described scientifically by Henri de Blainvil ...

can be hosts, but research is ongoing. The alcelaphine antelope affecting form is primarily found in Africa, in the natural habitat of wildebeest, hartebeest, and

topi ''Damaliscus lunatus jimela'' is a subspecies of topi, and is usually just called a topi. It is a highly social and fast type of antelope found in the savannas, semi-deserts, and floodplains of sub-Saharan Africa. Names The word ''tope'' or '' ...

. It has also occurred in zoos and

wild animal Wildlife refers to undomesticated animal species, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also synonymous to game: those birds and mammals that were hunted fo ...

parks that also kept wildebeest. The increasing popularity in North America of wild animal parks may spread its range further.

Transmission, clinical effects, and morbidity

Alcelaphine herpesvirus 2 is primarily transmitted by nasal emissions, by contact with water, flood, feces, or close contact. It can be destroyed by prolonged exposure to sunlight, but has a very long

incubation period Incubation period (also known as the latent period or latency period) is the time elapsed between exposure to a pathogenic organism, a chemical, or radiation, and when symptoms and signs are first apparent. In a typical infectious disease, the i ...

and thus may have a long period of time to infect other animals. There are three forms usually seen. The first a nasal form with fever, nasal inflammation and digestive problems that is very mild and only lasts a few days. The second is a more severe form that involves fever, diarrhea, heavy nasal discharge, and lymph system failure, with a

morbidity A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

of 28 percent. The so-called "head and eye" form is the most lethal and serious form, which results in all known effects and

central nervous system The central nervous system (CNS) is the part of the nervous system consisting primarily of the brain and spinal cord. The CNS is so named because the brain integrates the received information and coordinates and influences the activity of all par ...

damage, predated by nervous shakes and eventually muscular failure. Morbidity in some cases is as high as 90 percent.

Vaccination

As the primary infected strains of animals are wild and

free range Free range denotes a method of farming husbandry where the animals, for at least part of the day, can roam freely outdoors, rather than being confined in an enclosure for 24 hours each day. On many farms, the outdoors ranging area is fenced, ...

animals,

vaccination Vaccination is the administration of a vaccine to help the immune system develop immunity from a disease. Vaccines contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the organism. In stimulating ...

programs have been largely ineffective.

References

{{DEFAULTSORT:Alcelaphine Herpesvirus 2 Animal viral diseases Gammaherpesvirinae