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 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.
Rickettsia rickettsii is a Gram-negative, intracellular, coccobacillus bacterium that was first discovered in 1902. Having a reduced genome, the bacterium harvests nutrients from its host cell to carry out respiration, making it an organoheterotroph. Maintenance of its genome is carried out through vertical gene transfer where specialization of the bacterium allows it to shuttle host sugars directly into its TCA cycle.
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. Most of these pathogens require passage through vertebrate hosts as part of their life cycle. Tick-borne infections in humans, farm animals, and companion animals are primarily associated with wildlife animal reservoirs. Many tick-borne infections in humans involve a complex cycle between wildlife animal reservoirs and tick vectors. The survival and transmission of these tick-borne viruses are closely linked to their interactions with tick vectors and host cells. These viruses are classified into different families, including Asfarviridae, Reoviridae, Rhabdoviridae, Orthomyxoviridae, Bunyaviridae, and Flaviviridae.
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. 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.
Amblyomma is a genus of hard ticks. Some are disease vectors, for example the Rocky Mountain spotted fever in United States or ehrlichiosis in Brazil.
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.
Dermacentor andersoni, commonly known as the Rocky Mountain wood tick, is a hard tick, or member of the Ixodidae family, with three life stages including larvae, nymph, and finally adult, or, more entomologically, imago. This tick is generally located in the northwest United States and southwest Canada along the Rocky Mountains. This tick is generally a vector for Colorado tick fever, but can also be a vector for Rocky Mountain spotted fever and tularemia. During the larval and nymphal stages, the tick does not feed on humans, but during the adult stage, it will. Prevention of infections associated with these ticks is based on control of exposure to the vector, including wearing proper clothing when in woods/wet areas, and checking oneself thoroughly after returning home. Adult female ticks can feed for 5 to 15 days, thus removing a tick if present is very important. Follow general tick removal tips.
Rhipicephalus is a genus of ticks in the family Ixodidae, the hard ticks, consisting of about 74 or 75 species. Most are native to tropical Africa.
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.
Ornithodoros is a genus in the soft-bodied tick family, Argasidae.
Amblyomma triguttatum, commonly known as the kangaroo tick, is a species of tick in the genus Amblyomma native to Australia, in Western Australia, parts of Queensland, and in New South Wales.
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.
The Asian monitor lizard tick, is a hard-bodied tick of the genus Amblyomma. It is found in India, Thailand, Taiwan and Sri Lanka. Adults parasitize various reptiles such as varanids and snakes. These ticks are potential vectors of spotted fever group (SFG) rickettsiae.
Amblyomma albopictum is a species of tropical hard ticks. It is typically found parasitizing Cyclura nubila, Chilabothrus angulifer, Cubophis cantherigerus, Leiocephalus carinatus, and less commonly the Paraguaian hairy dwarf porcupine. The species has been found in Costa Rica, Cuba, Haiti, Honduras and the Dominican Republic, and has also been reported but not confirmed in Brazil. The tick was described by Louis Georges Neumann in 1899.
Maria Tonelli-Rondelli was an Italian entomologist who studied the taxonomy and identification of ticks (Ixodidae), especially South American species.
Amblyomma triste is a tick in the Amblyomma genus. The tick can be found in Venezuela, Argentina, Brasil, Colombia, Peru and Uruguay. Though not thought to be endemic to North America, a 2010 study found 27 specimens in 18 separate collections that had previously been misidentified in the United States.
