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Dermacentor
''Dermacentor'' is a genus of ticks in the family Ixodidae, the hard ticks. The genus has a cosmopolitan distribution, with native species on all continents except Australia. Most occur in the Nearctic realm. Hosts of ''Dermacentor'' ticks include many large and small mammals, including horses, deer, cattle, lagomorphs, peccaries, porcupines, tapirs, desert bighorn sheep, and humans. The American dog tick (''D. variabilis'') is a member of the genus. ''Dermacentor'' species are vectors of many pathogens, including ''Rickettsia rickettsii'', which causes the disease Rocky Mountain spotted fever, ''Coxiella burnetii'', which causes Q fever, ''Anaplasma marginale'', which causes anaplasmosis in cattle, ''Francisella tularensis'', which causes tularemia, '' Babesia caballi'', which causes equine piroplasmosis, and the ''Flavivirus'' that causes Powassan encephalitis. ''Dermacentor'' ticks inject a neurotoxin that causes tick paralysis. Species As of 2019, about 41 species are pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermacentor Occidentalis
''Dermacentor'' is a genus of ticks in the family Ixodidae, the hard ticks. The genus has a cosmopolitan distribution, with native species on all continents except Australia. Most occur in the Nearctic realm. Hosts of ''Dermacentor'' ticks include many large and small mammals, including horses, deer, cattle, lagomorphs, peccaries, porcupines, tapirs, desert bighorn sheep, and humans. The American dog tick (''D. variabilis'') is a member of the genus. ''Dermacentor'' species are vectors of many pathogens, including ''Rickettsia rickettsii'', which causes the disease Rocky Mountain spotted fever, ''Coxiella burnetii'', which causes Q fever, ''Anaplasma marginale'', which causes anaplasmosis in cattle, ''Francisella tularensis'', which causes tularemia, '' Babesia caballi'', which causes equine piroplasmosis, and the ''Flavivirus'' that causes Powassan encephalitis. ''Dermacentor'' ticks inject a neurotoxin that causes tick paralysis. Species As of 2019, about 41 species are pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermacentor Reticulatus
''Dermacentor reticulatus'', also known as the ornate cow tick, ornate dog tick, meadow tick, and marsh tick, is a species of tick from the family Ixodidae. It is the type species for the genus ''Dermacentor''. ''D. reticulatus'' is an ornate tick. The female varies in size from 3.8–4.2 mm (unfed) to 10 mm when engorged after feeding. The unfed male is 4.2–4.8 mm long. ''D. reticulatus'' is found in Europe and Western Asia, generally in wooded areas. Lifecycle ''D. reticulartus'' has a three-host development cycle. The adult female remains on a host for 9–15 days, and can lay 3000–4500 eggs, although the total number of eggs depends on the size of the female. The larva hatches from the egg in 14–21 days. Disease transmission ''D. reticulatus'' is a vector of various disease organisms, including ''Babesia canis'', ''Francisella tularensis'', ''Coxiella burnetti'', ''Theileria equi'', and several ''Rickettsia'' species, such as ''Rickettsia slovaca. See ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dermacentor Variabilis
''Dermacentor variabilis'', also known as the American dog tick or wood tick, is a species of tick that is known to carry bacteria responsible for several diseases in humans, including Rocky Mountain spotted fever and tularemia (''Francisella tularensis''). It is one of the best-known hard ticks. Diseases are spread when it sucks blood from the host. It may take several days for the host to experience symptoms. Though ''D. variabilis'' may be exposed to ''Borrelia burgdorferi'', the causative agent of Lyme disease, these ticks are not competent vectors for the transmission of this disease. The primary vectors for ''B. burgdorferi'' are the deer ticks ''Ixodes scapularis'' in eastern parts of the United States, ''Ixodes pacificus'' in California and Oregon, and ''Ixodes ricinus'' in Europe. ''D. variabilis'' may also carry ''Anaplasma phagocytophilum'', the causative agent of human granulocytic anaplasmosis, and ''Ehrlichia chaffeensis'', the causative agent of human monocytic eh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rocky Mountain Spotted Fever
Rocky Mountain spotted fever (RMSF) is a bacterial disease spread by ticks. It typically begins with a fever and headache, which is followed a few days later with the development of a rash. The rash is generally made up of small spots of bleeding and starts on the wrists and ankles. Other symptoms may include muscle pains and vomiting. Long-term complications following recovery may include hearing loss or loss of part of an arm or leg. The disease is caused by ''Rickettsia rickettsii'', a type of bacterium that is primarily spread to humans by American dog ticks, Rocky Mountain wood ticks, and brown dog ticks. Rarely the disease is spread by blood transfusions. Diagnosis in the early stages is difficult. A number of laboratory tests can confirm the diagnosis but treatment should be begun based on symptoms. It is within a group known as spotted fever rickettsiosis, together with ''Rickettsia parkeri'' rickettsiosis, Pacific Coast tick fever, and rickettsialpox. Treatment of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ixodidae
The Ixodidae are the family of hard ticks or scale ticks, one of the three families of ticks, consisting of over 700 species. They are known as 'hard ticks' because they have a scutum or hard shield, which the other major family of ticks, the 'soft ticks' (Argasidae), lack. They are ectoparasites of a wide range of host species, and some are vectors of pathogens that can cause human disease. Description They are distinguished from the Argasidae by the presence of a scutum. In both the nymph and the adult, a prominent gnathosoma (or capitulum, mouth and feeding parts) projects forward from the animal's body; in the Argasidae, conversely, the gnathosoma is concealed beneath the body. They differ, too, in their lifecycle; Ixodidae that attach to a host bite painlessly and are generally unnoticed, and they remain in place until they engorge and are ready to change their skin; this process may take days or weeks. Some species drop off the host to moult in a safe place, whereas others r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tick
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". 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 from the Cretaceous period, around 100 million years old. 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 cephalothorax and abdomen are completely fused. In addit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rickettsia Rickettsii
''Rickettsia rickettsii'' (abbreviated as ''R. rickettsii'') is a gram-negative, intracellular, coccobacillus bacterium that is around 0.8 to 2.0 μm long. ''R. rickettsii'' is the causative agent of Rocky Mountain spotted fever. ''R. rickettsii'' is one of the most pathogenic ''Rickettsia'' strains. It affects a large majority of the Western Hemisphere and small portions of the Eastern Hemisphere. History Rocky Mountain spotted fever (RMSF) first emerged in the Idaho Valley in 1896. At that time, not much information was known about the disease; it was originally called Black Measles because patients had a characteristic spotted rash appearance throughout their body. The first clinical description of Rocky Mountain Spotted Fever was reported in 1899 by Edward E. Maxey. Howard Ricketts (1871–1910), an associate professor of pathology at the University of Chicago in 1902, was the first to identify and study ''R. rickettsii''. At this time, the trademark rash now began to slowl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tick
Ticks (order Ixodida) are parasitic arachnids that are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, species, and "fullness". 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 from the Cretaceous period, around 100 million years old. 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 cephalothorax and abdomen are completely fused. In addit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acari
Mites are small arachnids (eight-legged arthropods). Mites span two large orders of arachnids, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari, but genetic analysis does not show clear evidence of a close relationship. Most mites are tiny, less than in length, and have a simple, unsegmented body plan. The small size of most species makes them easily overlooked; some species live in water, many live in soil as decomposers, others live on plants, sometimes creating galls, while others again are predators or parasites. This last type includes the commercially destructive ''Varroa'' parasite of honey bees, as well as scabies mites of humans. Most species are harmless to humans, but a few are associated with allergies or may transmit diseases. The scientific discipline devoted to the study of mites is called acarology. Evolution and taxonomy The mites are not a defined taxon, but is used for two distinct groups of arachni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lagomorpha
The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (hares and rabbits) and the Ochotonidae (pikas). The name of the order is derived from the Ancient Greek ''lagos'' (λαγώς, "hare") + ''morphē'' (μορφή, "form"). There are 110 recent species of lagomorph of which 109 are extant, including 34 species of pika, 42 species of rabbit, and 33 species of hare. Taxonomy and evolutionary history Other names used for this order, now considered synonymous, include: ''Duplicidentata'' - Illiger, 1811; ''Leporida'' - Averianov, 1999; ''Neolagomorpha'' - Averianov, 1999; ''Ochotonida'' - Averianov, 1999; and ''Palarodentia'' - Haeckel, 1895, Lilian, 2016. The evolutionary history of the lagomorphs is still not well understood. Until recently, it was generally agreed that '' Eurymylus'', which lived in eastern Asia and dates back to the late Paleocene or early Eocene, was an ancestor of the lagomorphs. More re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pathogen
In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term ''pathogen'' came into use in the 1880s. Typically, the term ''pathogen'' is used to describe an ''infectious'' microorganism or agent, such as a virus, bacterium, protozoan, prion, viroid, or fungus. Small animals, such as helminths and insects, can also cause or transmit disease. However, these animals are usually referred to as parasites rather than pathogens. The scientific study of microscopic organisms, including microscopic pathogenic organisms, is called microbiology, while parasitology refers to the scientific study of parasites and the organisms that host them. There are several pathways through which pathogens can invade a host. The principal pathways have different episodic time frames, but soil has the longest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vector (epidemiology)
In epidemiology, a disease vector is any living agent that carries and transmits an infectious pathogen to another living organism; agents regarded as vectors are organisms, such as parasites or microbes. The first major discovery of a disease vector came from Ronald Ross in 1897, who discovered the malaria pathogen when he dissected a mosquito. Arthropods Arthropods form a major group of pathogen vectors with mosquitoes, flies, sand flies, lice, fleas, ticks, and mites transmitting a huge number of pathogens. Many such vectors are haematophagous, which feed on blood at some or all stages of their lives. When the insects feed on blood, the pathogen enters the blood stream of the host. This can happen in different ways. The ''Anopheles'' mosquito, a vector for malaria, filariasis, and various arthropod-borne-viruses (arboviruses), inserts its delicate mouthpart under the skin and feeds on its host's blood. The parasites the mosquito carries are usually located in its salivary gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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