| Trypanosoma vivax | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Phylum: | Euglenozoa |
| Class: | Kinetoplastea |
| Order: | Trypanosomatida |
| Family: | Trypanosomatidae |
| Genus: | Trypanosoma |
| Species: | T. vivax |
| Binomial name | |
| Trypanosoma vivax Ziemann, 1905 | |
| Synonyms | |
Trypanosoma vivax is a parasite species in the genus Trypanosoma . It causes the disease nagana, affecting cattle or wild mammals. It is mainly occurs in West Africa, although it has spread to South America. [3] [1]
Historically restricted to sub-Saharan Africa especially West Africa, it has spread to 13 countries of South America. This has been made easier by its mechanical transmission route, see § Life cycle below. [1]
Hosts include, cattle, horses, sheep, and camels. [2] [1] As of 2016 [update] in South America it is an emerging pathogen of cattle, and sometimes horses and other ruminants. [1]
Unusual for a trypanosome, T. vivax does not infect the Glossina vector midgut. Instead it infects and completes an abbreviated life cycle only in the vector's proboscis. Thus it is entirely mechanically transmitted. For this reason it has had a relatively easy time jumping vectors, and thereby even jumping geographic ranges which do not have its customary vector. [1]
Symptoms of T. vivax include "rapid weight loss, lethargy, weakness, clumsiness, pale mucosa, swelling of superficial lymph nodes, anemia, and fluctuating pyrexia, causing[...]a drop in animal productivity." [4]
A novel proline racemase of medical and veterinary importance has been described in T. vivax ( B8LFE4 ). [5]
It also produces vivapain, a cysteine peptidase. [6]
The smallest variable surface glycoprotein (40 kDa in size) to date has been found in T. vivax, which bears little carbohydrate. [7]
Trypanosoma vivax is a significant drag on Africa's cattle production every year, and increasingly is a concern in South America: One outbreak in 1995 in the Pantanal in Brazil and Bolivia cost the industry over US$160 million. [1]
Some resistance to trypanocides has been observed: Some African countries have isometamidium-resistant populations, with some of these also being resistant to diminazene [8] [9] . (This has been ascribed variously to cross-resistance or to two separate events of acquisition of separate resistance genetics. Isometamidium and diminazene are not thought to be in the same trypanocide class.) Resistance to both is widespread in both West and East Africa. Diminazene resistance has been observed in South America. [1]
Mechanisms of resistance are not necessarily shared across the genus, and this is especially true for this, the most genetically divergent species. [1]
African trypanosomiasis is an insect-borne parasitic infection of humans and other animals.
Tsetse are large, biting flies that inhabit much of tropical Africa. Tsetse flies include all the species in the genus Glossina, which are placed in their own family, Glossinidae. The tsetse is an obligate parasite, which lives by feeding on the blood of vertebrate animals. Tsetse has been extensively studied because of their role in transmitting disease. They have pronounced economic and public health impacts in sub-Saharan Africa as the biological vectors of trypanosomes, causing human and animal trypanosomiasis.
Trypanosoma is a genus of kinetoplastids, a monophyletic group of unicellular parasitic flagellate protozoa. Trypanosoma is part of the phylum Euglenozoa. The name is derived from the Greek trypano- (borer) and soma (body) because of their corkscrew-like motion. Most trypanosomes are heteroxenous and most are transmitted via a vector. The majority of species are transmitted by blood-feeding invertebrates, but there are different mechanisms among the varying species. Trypanosoma equiperdum is spread between horses and other equine species by sexual contact. They are generally found in the intestine of their invertebrate host, but normally occupy the bloodstream or an intracellular environment in the vertebrate host.
Diminazene is an anti-infective medication for animals that is sold under a variety of brand names. It is effective against certain protozoa such as Babesia, Trypanosoma, and Cytauxzoon. The drug may also be effective against certain bacteria including Brucella and Streptococcus.
Plasmodium vivax is a protozoal parasite and a human pathogen. This parasite is the most frequent and widely distributed cause of recurring malaria. Although it is less virulent than Plasmodium falciparum, the deadliest of the five human malaria parasites, P. vivax malaria infections can lead to severe disease and death, often due to splenomegaly. P. vivax is carried by the female Anopheles mosquito; the males do not bite.
Trypanosoma brucei is a species of parasitic kinetoplastid belonging to the genus Trypanosoma that is present in sub-Saharan Africa. Unlike other protozoan parasites that normally infect blood and tissue cells, it is exclusively extracellular and inhabits the blood plasma and body fluids. It causes deadly vector-borne diseases: African trypanosomiasis or sleeping sickness in humans, and animal trypanosomiasis or nagana in cattle and horses. It is a species complex grouped into three subspecies: T. b. brucei, T. b. gambiense and T. b. rhodesiense. The first is a parasite of non-human mammals and causes nagana, while the latter two are zoonotic infecting both humans and animals and cause African trypanosomiasis.
Trypanosoma evansi is a parasitic species of excavate trypanosome in the genus Trypanosoma that is one cause of surra in animals. Discovered by Griffith Evans in 1880 at Dera Ismail Khan, it is the first known trypanosome that causes infection. It is a common parasite in India and Iran and causes acute disease in camels and horses, and chronic disease in cattle and buffalo. In Pakistan, it has been found to be the most prevalent trypanosome species in donkeys. It is now established to infect other mammals, including humans.
Moxidectin is an anthelmintic drug used in animals to prevent or control parasitic worms (helminths), such as heartworm and intestinal worms, in dogs, cats, horses, cattle, sheep and wombats. Moxidectin kills some of the most common internal and external parasites by selectively binding to a parasite's glutamate-gated chloride ion channels. These channels are vital to the function of invertebrate nerve and muscle cells; when moxidectin binds to the channels, it disrupts neurotransmission, resulting in paralysis and death of the parasite.
Animal trypanosomiasis, also known as nagana and nagana pest, or sleeping sickness, is a disease of vertebrates. The disease is caused by trypanosomes of several species in the genus Trypanosoma such as T. brucei. T. vivax causes nagana mainly in West Africa, although it has spread to South America. The trypanosomes infect the blood of the vertebrate host, causing fever, weakness, and lethargy, which lead to weight loss and anemia; in some animals the disease is fatal unless treated. The trypanosomes are transmitted by tsetse flies.
In enzymology, a proline racemase is an enzyme that catalyzes the chemical reaction
Trypanosoma congolense is a species of trypanosomes and is the major pathogen responsible for the disease nagana in cattle and other animals including sheep, pigs, goats, horses and camels, dogs, as well as laboratory mice. It is the most common cause of nagana in east Africa, but is also a major cause of nagana in west Africa. This parasite is spread by tsetse flies. In its mammalian host, Trypanosoma congolense only lives in blood vessels, and causes in particular anaemia.
A trypanocidal agent is an antiprotozoal agent that acts upon trypanosome parasites.
A Trypanosomiasis vaccine is a vaccine against trypanosomiasis. No effective vaccine currently exists, but development of a vaccine is the subject of current research.
The Asian blue tick is an economically important tick that parasitises a variety of livestock and wild mammal species, especially cattle, on which it is the most economically significant ectoparasite in the world. It is known as the Australian cattle tick, southern cattle tick, Cuban tick, Madagascar blue tick, and Puerto Rican Texas fever tick.
Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may also be called vermifuges or vermicides. Anthelmintics are used to treat people who are infected by helminths, a condition called helminthiasis. These drugs are also used to treat infected animals, particularly small ruminants such as goats and sheep.
Variant surface glycoprotein (VSG) is a ~60kDa protein which densely packs the cell surface of protozoan parasites belonging to the genus Trypanosoma. This genus is notable for their cell surface proteins. They were first isolated from Trypanosoma brucei in 1975 by George Cross. VSG allows the trypanosomatid parasites to evade the mammalian host's immune system by extensive antigenic variation. They form a 12–15 nm surface coat. VSG dimers make up ~90% of all cell surface protein and ~10% of total cell protein. For this reason, these proteins are highly immunogenic and an immune response raised against a specific VSG coat will rapidly kill trypanosomes expressing this variant. However, with each cell division there is a possibility that the progeny will switch expression to change the VSG that is being expressed. VSG has no prescribed biochemical activity.
Glossina fuscipes is a riverine fly species in the genus Glossina, which are commonly known as tsetse flies. Typically found in sub-Saharan Africa but with a small Arabian range, G. fuscipes is a regional vector of African trypanosomiasis, commonly known as sleeping sickness, that causes significant rates of morbidity and mortality among humans and livestock. Consequently, the species is among several being targeted by researchers and veterinary and public health authorities for population control as a method for controlling the disease.
A trypanotolerant organism is one which is relatively less affected by trypanosome infestation.
Glossina morsitans is a species of tsetse fly. It is one of the major vectors of Trypanosoma brucei rhodesiense in African savannas.
The Sleeping Sickness Commission was a medical project established by the British Royal Society to investigate the outbreak of African sleeping sickness or African trypanosomiasis in Africa at the turn of the 20th century. The outbreak of the disease started in 1900 in Uganda, which was at the time a protectorate of the British Empire. The initial team in 1902 consisted of Aldo Castellani and George Carmichael Low, both from the London School of Hygiene and Tropical Medicine, and Cuthbert Christy, a medical officer on duty in Bombay, India. From 1903, David Bruce of the Royal Army Medical Corps and David Nunes Nabarro of the University College Hospital took over the leadership. The commission established that species of blood protozoan called Trypanosoma brucei, named after Bruce, was the causative parasite of sleeping sickness.
"Trypanosoma vivax". National Center for Biotechnology Information (NCBI).