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Ornithodoros
''Ornithodoros'' is a genus in the soft-bodied tick family, Argasidae. It is distinguished from other genera in the family by the absence of a lateral 'suture' line. It is the largest genus within Argasidae, consisting of approximately 130 species. ''Ornithodoros'' ticks are parasitic associates of shelter-seeking vertebrates, such as mammals, birds and reptiles. Prior to its reclassification in 1844, the genus ''Ornithodoros'' was described under the genus ''Argas''. Physiology The opening between the midgut and hindgut has been lost, preventing these ticks from excreting digestive waste products from their bodies. Habitat The genus ''Ornithodoros'' have been documented worldwide, with the highest occurrence in the Palearctic realm, Paleartic realm. Life Cycle The life cycle of all species of ''Ornithodoros'' is Parasitism, parasitic and relies on one or multiple hosts, most of which are shelter-seeking vertebrates, and can also parasitize humans. Mating and moulting occ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithodoros Savignyi
''Ornithodoros savignyi'', known as sand tampan, African eyed tampan or Kalahari sand tampan, is one of some 37 species in the genus ''Ornithodoros'' and is a Argasidae, soft tick with a leathery, mammillated integument, causing paralysis and tampan toxicosis, two unrelated conditions. The sand tampan is an ectoparasite on humans, their livestock and wild animals, including birds and bats. Occurring in semi-desert areas of Africa, Saudi Arabia and other parts of the Persian Gulf, India, Sri Lanka and into Asia, it is able to survive for lengthy periods without feeding, spending most of its life burrowed under sand or loose soil, often in wait for animals that rest or sleep under trees or in the lee of rocks, but also in places where people or their animals congregate such as marketplaces, places of worship, cattle kraals and village squares. The timing of its activity is geared to coincide with that of potential hosts, but hot sunny conditions are usually avoided. Because of its ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tick
Ticks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks are external parasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians. The timing of the origin of ticks is uncertain, though the oldest known tick fossils are around 100 million years old, and come from the Cretaceous period. Ticks are widely distributed around the world, especially in warm, humid climates. Ticks belong to two major families: the Ixodidae, or hard ticks, and the Argasidae, or soft ticks. '' Nuttalliella'', a genus of tick from southern Africa, is the only member of the family Nuttalliellidae, and represents the most primitive living lineage of ticks. Adults have ovoid/pear-shaped bodies (idiosomas) which become engorged with blood when they feed, and eight legs. Their cephalotho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Relapsing Fever
Relapsing fever is a vector-borne disease caused by infection with certain bacteria in the genus '' Borrelia'', which is transmitted through the bites of lice, soft-bodied ticks (genus '' Ornithodoros''), or hard-bodied ticks (Genus Ixodes). Signs and symptoms Most infected people develop sickness between 5 and 15 days after they are bitten. The symptoms may include a sudden fever, chills, headaches, muscle or joint aches, and nausea. A rash may also occur. These symptoms usually continue for 2 to 9 days, then disappear. This cycle may continue for several weeks if the person is not treated. Causes Louse-borne relapsing fever Along with '' Rickettsia prowazekii'' and '' Bartonella quintana'', '' Borrelia recurrentis'' is one of three pathogens of which the body louse ('' Pediculus humanus humanus'') is a vector. Louse-borne relapsing fever is more severe than the tick-borne variety. Louse-borne relapsing fever occurs in epidemics amid poor living conditions, famine, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tick-borne Relapsing Fever
Relapsing fever is a vector-borne disease caused by infection with certain bacteria in the genus '' Borrelia'', which is transmitted through the bites of lice, soft-bodied ticks (genus ''Ornithodoros''), or hard-bodied ticks (Genus Ixodes). Signs and symptoms Most infected people develop sickness between 5 and 15 days after they are bitten. The symptoms may include a sudden fever, chills, headaches, muscle or joint aches, and nausea. A rash may also occur. These symptoms usually continue for 2 to 9 days, then disappear. This cycle may continue for several weeks if the person is not treated. Causes Louse-borne relapsing fever Along with '' Rickettsia prowazekii'' and '' Bartonella quintana'', '' Borrelia recurrentis'' is one of three pathogens of which the body louse ('' Pediculus humanus humanus'') is a vector. Louse-borne relapsing fever is more severe than the tick-borne variety. Louse-borne relapsing fever occurs in epidemics amid poor living conditions, famine, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Swine Fever Virus
African swine fever virus (ASFV) is a large, double-stranded DNA virus in the ''Asfarviridae'' family. It is the causative agent of African swine fever (ASF). The virus causes a haemorrhagic fever, hemorrhagic fever with high mortality rates in domestic pigs; some isolates can cause death of animals as quickly as a week after infection. It persistently infects its natural hosts, warthogs, bushpigs, and soft ticks of the genus ''Ornithodoros'', which likely act as a vector (epidemiology), vector, with no disease signs. It does not cause disease in humans. ASFV is endemic to sub-Saharan Africa and exists in the wild through a cycle of infection between ticks and wild pigs, bushpigs, and warthogs. The disease was first described after European settlers brought pigs into areas endemic with ASFV, and as such, is an example of an emerging infectious disease. ASFV replicates in the cytoplasm of infected cells. It is the only virus with a double-stranded DNA genome known to be transmi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Borrelia
''Borrelia'' is a genus of bacteria of the spirochete phylum. Several species cause Lyme disease, also called Lyme borreliosis, a zoonotic, vector-borne disease transmitted by ticks. Other species of ''Borrelia'' cause relapsing fever, and are transmitted by ticks or lice, depending on the species of bacteria. The genus is named after French biologist Amédée Borrel (1867–1936), who first documented the distinction between a species of ''Borrelia anserina'' and the other known type of spirochete at the time, ''Treponema pallidum''. This bacterium must be viewed using dark-field microscopy, which make the cells appear white against a dark background. ''Borrelia'' species are grown in Barbour-Stoenner-Kelly medium. Of 52 known species of ''Borrelia'', 20 are members of the Lyme disease group (with an additional 3 proposed), 29 belong to the relapsing fever group, and two are members of a genetically distinct third group typically found in reptiles. A proposal has been made ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argasidae
The Argasidae are the family of soft ticks, one of the three families of ticks. The family contains 193 species, although the composition of the genera is less certain, and more study is needed before the genera can become stable. The currently accepted genera are '' Antricola'', '' Argas'', '' Nothoaspis'', ''Ornithodoros'', and '' Otobius''. The Argasidae are very common in South Asia, along with 96 other species of ticks, making South Asia the region with the highest biodiversity of ticks worldwide. Soft ticks are resistant to desiccation and can live for several years in arid Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata ... conditions. Physical characteristics Soft ticks lack the hard scutum present in the hard ticks ( Ixodidae). The gnathosoma (or capitulum, the mouthparts ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Autogeny
In entomology, anautogeny is a reproductive strategy in which an adult female insect must eat a particular sort of meal (generally vertebrate blood) before laying eggs in order for her eggs to mature. This behavior is most common among dipteran insects, such as mosquitoes. Anautogenous animals often serve as vectors for infectious disease in their hosts because of their contact with hosts' blood. The opposite trait (needing no special food as an adult to successfully reproduce) is known as autogeny. Factors governing anautogeny Anautogenous insects generally reach adulthood without sufficient reserves of nutrients (particularly protein) to produce viable eggs, necessitating additional feeding as adults. A high-protein meal, usually of blood, allows the production of yolk to nourish the eggs and makes reproduction possible. This blood is typically obtained through ectoparasitism on large vertebrates. However, even individuals who do have the reserves needed to produce viable egg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palearctic Realm
The Palearctic or Palaearctic is a biogeographic realm of the Earth, the largest of eight. Confined almost entirely to the Eastern Hemisphere, it stretches across Europe and Asia, north of the foothills of the Himalayas, and North Africa. The realm consists of several bioregions: the Mediterranean Basin; North Africa; North Arabia; Western, Central and East Asia. The Palaearctic realm also has numerous rivers and lakes, forming several freshwater ecoregions. Both the eastern and westernmost extremes of the Paleartic span into the Western Hemisphere, including Cape Dezhnyov in Chukotka Autonomous Okrug to the east and Iceland to the west. The term was first used in the 19th century, and is still in use as the basis for zoogeographic classification. History In an 1858 paper for the ''Proceedings of the Linnean Society'', British zoologist Philip Sclater first identified six terrestrial zoogeographic realms of the world: Palaearctic, Aethiopian/ Afrotropic, Indian/ Indom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood-borne Disease
A blood-borne disease is a disease that can be spread through contamination by blood and other body fluids. Blood can contain pathogens of various types, chief among which are microorganisms, like bacteria and parasites, and non-living infectious agents such as viruses. Three blood-borne pathogens in particular, all viruses, are cited as of primary concern to health workers by the CDC-NIOSH: human immunodeficiency virus, hepatitis B, and hepatitis C. Diseases that are not usually transmitted directly by blood contact, but rather by insect or other vector, are more usefully classified as vector-borne disease, even though the causative agent can be found in blood. Vector-borne diseases include West Nile virus, zika fever and malaria. Many blood-borne diseases can also be contracted by other means, including high-risk sexual behavior or intravenous drug use. These diseases have also been identified in sports medicine. Since it is difficult to determine what pathogens any given sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hematophagy
Hematophagy (sometimes spelled haematophagy or hematophagia) is the practice by certain animals of feeding on blood (from the Greek words αἷμα ' "blood" and φαγεῖν ' "to eat"). Since blood is a fluid tissue rich in nutritious proteins and lipids that can be taken without great effort, hematophagy is a preferred form of feeding for many small animals, such as worms and arthropods. Some intestinal nematodes, such as Ancylostomatids, feed on blood extracted from the capillaries of the gut, and about 75 percent of all species of leeches (e.g., '' Hirudo medicinalis'') are hematophagous. The spider '' Evarcha culicivora'' feeds indirectly on vertebrate blood by specializing on blood-filled female mosquitoes as their preferred prey. Some fish, such as lampreys and candirus; mammals, especially vampire bats; and birds, including the vampire finch, Hood mockingbird, Tristan thrush, and oxpeckers, also practise hematophagy. Mechanism and evolution Hematop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Instar
An instar (, from the Latin '' īnstar'' 'form, likeness') is a developmental stage of arthropods, such as insects, which occurs between each moult (''ecdysis'') until sexual maturity is reached. Arthropods must shed the exoskeleton in order to grow or assume a new form. Differences between instars can often be seen in altered body proportions, colors, patterns, changes in the number of body segments or head width. After shedding their exoskeleton (moulting), the juvenile arthropods continue in their life cycle until they either pupate or moult again. The instar period of growth is fixed; however, in some insects, like the salvinia stem-borer moth, the number of instars depends on early larval nutrition. Some arthropods can continue to moult after sexual maturity, but the stages between these subsequent moults are generally not called instars. For most insect species, an ''instar'' is the developmental stage of the larval forms of holometabolous (complete metamorphism) or ny ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
