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.
Ticks 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.
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.
Tick-borne diseases, which afflict humans and other animals, are caused by infectious agents transmitted by tick bites. They are caused by infection with a variety of pathogens, including rickettsia and other types of bacteria, viruses, and protozoa. The economic impact of tick-borne diseases is considered to be substantial in humans, and tick-borne diseases are estimated to affect ~80 % of cattle worldwide.
Amblyomma americanum, also known as the lone star tick, the northeastern water tick, or the turkey tick, is a type of tick indigenous to much of the eastern United States and Mexico, that bites painlessly and commonly goes unnoticed, remaining attached to its host for as long as seven days until it is fully engorged with blood. It is a member of the phylum Arthropoda, class Arachnida. The adult lone star tick is sexually dimorphic, named for a silvery-white, star-shaped spot or "lone star" present near the center of the posterior portion of the adult female shield (scutum); adult males conversely have varied white streaks or spots around the margins of their shields.
Ehrlichia chaffeensis is an obligate intracellular, Gram-negative species of Rickettsiales bacteria. It is a zoonotic pathogen transmitted to humans by the lone star tick. It is the causative agent of human monocytic ehrlichiosis.
Ixodes pacificus, the western black-legged tick, is a species of parasitic tick found on the western coast of North America. I. pacificus is a member of the Ixodidae (hard-bodied) family. It is the principal vector of Lyme disease in that region. I. pacificus typically feeds on lizards and small mammals therefore its rate of transmission of Lyme disease to humans is around 1% of adults. It is an ectoparasite that attaches itself to the outside of its host and feeds on the host's blood. It can have a heteroxenous lifestyle or monoxenous life cycle depending on how many hosts it feeds on in each cycle. I. pacificus has a four stage life cycle that takes around 3 years to complete. These stages include egg, larva, nymph, and adult. They prefer dense woodland habitats or areas of brush and tall grass.
African tick bite fever (ATBF) is a bacterial infection spread by the bite of a tick. Symptoms may include fever, headache, muscle pain, and a rash. At the site of the bite there is typically a red skin sore with a dark center. The onset of symptoms usually occurs 4–10 days after the bite. Complications are rare but may include joint inflammation. Some people do not develop symptoms.
Amblyomma cajennense or Cayenne tick is a species of tick found in a range from the southern part of the United States to northern Argentina, through Central America and some of the Caribbean. As a consequence the species has adapted to a wide range of environmental conditions. There are also major geographic barriers such as large rivers and the Andes mountain range.
Rickettsia parkeri is a gram-negative intracellular bacterium. The organism is found in the Western Hemisphere and is transmitted via the bite of hard ticks of the genus Amblyomma. R. parkeri causes mild spotted fever disease in humans, whose most common signs and symptoms are fever, an eschar at the site of tick attachment, rash, headache, and muscle aches. Doxycycline is the most common drug used to reduce the symptoms associated with disease.
Ticks of domestic animals directly cause poor health and loss of production to their hosts. Ticks also transmit numerous kinds of viruses, bacteria, and protozoa between domestic animals. These microbes cause diseases which can be severely debilitating or fatal to domestic animals, and may also affect humans. Ticks are especially important to domestic animals in tropical and subtropical countries, where the warm climate enables many species to flourish. Also, the large populations of wild animals in warm countries provide a reservoir of ticks and infective microbes that spread to domestic animals. Farmers of livestock animals use many methods to control ticks, and related treatments are used to reduce infestation of companion animals.
Amblyomma patinoi is a species of tick of the genus Amblyomma. The species is associated with the Eastern Cordillera of Colombia. Rickettsia species can habitate A. patinoi endosymbiotically.
Amblyomma interandinum is a species of tick of the genus Amblyomma. The species is associated with the northern part of the Inter-Andean valley of Peru. Rickettsia species can habitate A. interandinum endosymbiotically.
Amblyomma tonelliae is a species of tick of the genus Amblyomma. The species is associated with dry areas of the Chaco region, spanning central-northern Argentina to Bolivia and Paraguay. Rickettsia species can habitate A. tonelliae endosymbiotically.
Amblyomma gervaisi is a hard-bodied tick of the genus Amblyomma. The tick is a parasite of snakes, such as Naja naja, Python molurus species and monitor species such as Varanus ocellatus, Varanus yemenensis, Varanus benghalensis, Varanus griseus and many other Varanus species in southeastern Asia and Asia-minor. They exhibit sexual dimorphism. They can be found in Sri Lanka, India, Yemen, Saudi Arabia. It is a potential vector for Coxiella burnetii.
Amblyomma testudinarium is a hard-bodied tick of the genus Amblyomma. It is found in Indonesia, India, Japan, Thailand, Sri Lanka and Vietnam. Adults parasitize various larger mammals such as buffalo and cattle, whereas nymphs and larvae use mostly larger and medium mammals.
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.
Ixodes tasmani, colloquially known as the common marsupial tick, is an Australian species of hard-bodied tick. It is a common vector for certain pathogens. There are around 70 species of ticks found in Australia, 16 of which, Ixodes tasmani included, are able to parasitize humans.
Maria Tonelli-Rondelli was an Italian entomologist who studied the taxonomy and identification of ticks (Ixodidae), especially South American species.
