Alcelaphine gammaherpesvirus 2 (AlHV-2), also called Alcelaphine herpesvirus 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 Fauna of Africa, African antelope. It is the Monotypic taxon, only member of the genus ''Alcelaphus''. Eight subspecies have been described, including two som ...

infections of malignant catarrhal fever.

Clinical definition

Distantly related to human

herpes Herpes simplex, often known simply as herpes, is a viral infection caused by the herpes simplex virus. Herpes infections are categorized by the area of the body that is infected. The two major types of herpes are oral herpes and genital herp ...

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

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

segments, aligned along a long

chromosome A chromosome is a package of DNA containing part or all of the genetic material of an organism. In most chromosomes, the very long thin DNA fibers are coated with nucleosome-forming packaging proteins; in eukaryotic cells, the most import ...

surrounded by terminal

DNA Deoxyribonucleic acid (; DNA) is a polymer composed of two polynucleotide chains that coil around each other to form a double helix. The polymer carries genetic instructions for the development, functioning, growth and reproduction of al ...

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, lymphoid organs, lympha ...

, 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 ...

s, and occasionally

necrosis Necrosis () is a form of cell injury which results in the premature death of cells in living tissue by autolysis. The term "necrosis" came about in the mid-19th century and is commonly attributed to German pathologist Rudolf Virchow, who i ...

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 complex system, highly complex part of an animal that coordinates its behavior, actions and sense, sensory information by transmitting action potential, signals to and from different parts of its body. Th ...

. Occasionally, lesions,

arthritis Arthritis is a general medical term used to describe a disorder that affects joints. Symptoms generally include joint pain and stiffness. Other symptoms may include redness, warmth, Joint effusion, swelling, and decreased range of motion of ...

, 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 refers to numerous extant or recently extinct species of the ruminant artiodactyl family Bovidae that are indigenous to most of Africa, India, the Middle East, Central Asia, and a small area of Eastern Europe. Antelopes do no ...

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

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

sheep Sheep (: sheep) or domestic sheep (''Ovis aries'') are a domesticated, ruminant mammal 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 d ...

, 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 A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

gnu GNU ( ) is an extensive collection of free software (394 packages ), 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 operating systems popu ...

, 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-toed ...

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

direct evidence In law, a body of facts that directly supports the truth of an assertion without intervening inference. It is often exemplified by eyewitness testimony, which consists of a witness's description of their reputed direct sensory experience of an ...

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 Damaliscus lunatus, 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 ...

. It has also occurred in zoos and

wild animal Wildlife refers to undomesticated animals and uncultivated plant species which can exist in their natural habitat, but has come to include all organisms that grow or live wild in an area without being introduced by humans. Wildlife was also ...

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 ionizing radiation, radiation, and when symptoms and signs are first apparent. In a typical infect ...

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 adversely affects the structure or function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical conditions that are asso ...

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, spinal cord and retina. The CNS is so named because the brain integrates the received information and coordinates and influences the activity o ...

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 can roam freely outdoors for at least part of the day, rather than being confined in an enclosure for 24 hours each day. On many farms, the outdoors ranging area is fenced, th ...

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