Male Cayenne Tick, Amblyomma Cajennense

Male Cayenne Tick, Amblyomma Cajennense

Male Cayenne Tick, Amblyomma Cajennense

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).

Note the large scutum, or “shield”, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen. Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.

Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of RMSF, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.

Male cayenne Tick (Amblyomma Cajennense)

Male cayenne Tick (Amblyomma Cajennense)

Male cayenne Tick (Amblyomma Cajennense)

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).

Note the large scutum, or “shield”, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen. Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.

Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of RMSF, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.

Male Rocky Mountain Wood Tick (Dermacentor andersoni)

Male Rocky Mountain Wood Tick (Dermacentor andersoni)

Male Rocky Mountain Wood Tick (Dermacentor andersoni)

This photograph depicts a dorsal view of a male Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.

Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.

Rickettsia rickettsii usually infects members of the tick family Ixodidae (hard ticks), although a closely related rickettsia has been found in the soft bat tick, Carios kelleyi. These ticks have four stages in their life cycle: egg, larva, nymph, and adult. After the eggs hatch, each stage must feed once to develop into the next stage. Both male and female ticks will bite.

Rickettsiae are transmitted to a vertebrate host through saliva while a tick is feeding. It usually takes several hours of attachment and feeding, before the rickettsiae are transmitted to the host. The risk of exposure to a tick carrying R. rickettsii is low. In general, about 1%-3% of the tick population carries R. rickettsii, even in areas where the majority of human cases are reported.

Male Rocky Mountain Wood Tick (Dermacentor Andersoni)

Male Rocky Mountain Wood Tick (Dermacentor Andersoni)

Male Rocky Mountain Wood Tick (Dermacentor Andersoni)

This photograph depicts a dorsal view of a male Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.

Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.

Rickettsia rickettsii usually infects members of the tick family Ixodidae (hard ticks), although a closely related rickettsia has been found in the soft bat tick, Carios kelleyi. These ticks have four stages in their life cycle: egg, larva, nymph, and adult. After the eggs hatch, each stage must feed once to develop into the next stage. Both male and female ticks will bite.

Rickettsiae are transmitted to a vertebrate host through saliva while a tick is feeding. It usually takes several hours of attachment and feeding, before the rickettsiae are transmitted to the host. The risk of exposure to a tick carrying R. rickettsii is low. In general, about 1%-3% of the tick population carries R. rickettsii, even in areas where the majority of human cases are reported.

Female Rocky Mountain Wood Tick, (Dermacentor andersoni)

Female Rocky Mountain Wood Tick, (Dermacentor andersoni)

Female Rocky Mountain Wood Tick, (Dermacentor andersoni)

This photograph depicts a dorsal view of a female Rocky Mountain wood tick, Dermacentor andersoni. This tick specie is a known North American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever.

Dermacentor andersoni is found in the Rocky Mountain states and in southwestern Canada. The life cycle of this tick may require up to 2 to 3 years for completion. Adult wood ticks feed primarily on large mammals, while the larvae and nymphs feed on small rodents.

Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.

An Unidentified Male Dermacentor sp. Tick

An Unidentified Male Dermacentor sp. Tick

An Unidentified Male Dermacentor sp. Tick

Under a low magnification of 23X, this scanning electron micrograph (SEM) depicted a dorsal view of an unidentified male Dermacentor sp. tick found upon a cat in the suburbs of Decatur, Georgia, which measured approximately 3.5mm from its gnathosoma (i.e., capitulum), which is where its mouthparts are located, to the distal abdominal margin. Note that the entire dorsum of this tick’s abdomen is covered by its tough “scutum”, or “shield”, categorizing it as a male, whereas, in female Ixodid-species ticks, the scutum only partially covers the dorsal abdomen. The ridges running along the distal abdominal border are known as “festoons”.

Ticks belong to the Phylum Arthropoda, due to the fact that they maneuver upon jointed ( “Arthro”) legs (“poda”), as well as the Class Arachnida, for they’ve eight of these legs, unlike insects, which use six legs to move about. Ticks act as the vectors for a number of what are termed “Arboviruses”, i.e., Arthropod-borne, including Lyme disease (Borrelia burgdorferi), Rocky Mountain spotted fever (RMSF) (Rickettsia rickettsii), Tularemia (Francisella tularensis), and human granulocytic ehrlichiosis (HGE) (Ehrlichia chaffeensis).

A Male “brown dog tick” (Rhipicephalus Sanguineus)

A Male “brown dog tick” (Rhipicephalus Sanguineus)

A Male “brown dog tick” (Rhipicephalus Sanguineus)

This 2005 image depicted a male “brown dog tick”, Rhipicephalus sanguineus from a superior, or dorsal view looking down on this “hard tick’s” scutum, or keratinized “shield” which entirely covers its back, identifying it as a male. In the female, the dorsal abdomen is only partially covered, thereby, offering room for abdominal expansion when she becomes engorged with blood while ingesting her blood meal obtained from her host.

Though not the primary vector for Rocky Mountain spotted fever (RMSF) like the “American dog tick”, Dermacentor variabilis, and the “Rocky Mountain wood tick” D. andersoni, R. sanguineus has been found to be a less-common vector as well. This tick is distributed throughout the world. It also is known to transmit diseases to animals including canine babesiosis, bovine anaplasmosis, East Coast fever and Texas cattle fever. It can also spread tularemia, and tick-borne typhus to human beings.

RMSF, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of Rocky Mountain spotted fever, ticks are the natural hosts, serving as both reservoirs and vectors of Rickettsia rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.

R. rickettsii usually infects members of the tick family Ixodidae spp. (hard ticks), however, a closely related rickettsial specie has been found in the soft “bat tick”, Carios kelleyi. These ticks have four stages in their life cycle: egg, larva, nymph, and adult. Both male and female ticks will bite.

A Male Cayenne Tick (Amblyomma cajennense)

A Male Cayenne Tick (Amblyomma cajennense)

A Male Cayenne Tick (Amblyomma cajennense)

This photograph depicts a dorsal view of a male cayenne tick, Amblyomma cajennense. This tick specie is a known North, Central and South American vector of Rickettsia rickettsii, which is the etiologic agent of Rocky Mountain spotted fever (RMSF).

Note the large scutum, or “shield”, which unlike its female counterpart, covers the entire surface of this specimen’s dorsal abdomen.

Like the female of the specie, the male also possesses four pairs of legs, placing it in the class of Arachnida, as are spiders and scorpions. Two of this specimen’s legs are tucked up underneath its abdomen.

Rocky Mountain spotted fever, like all rickettsial infections, is classified as a zoonosis. Zoonoses are diseases of animals that can be transmitted to humans. Many zoonotic diseases require a biological vector (e.g., a mosquito, tick, flea, or mite) in order to be transmitted from the animal host to the human host. In the case of RMSF, ticks are the natural hosts, serving as both reservoirs and vectors of R. rickettsii. Ticks transmit the organism to vertebrates primarily by their bite. Less commonly, infections may occur following exposure to crushed tick tissues, fluids, or tick feces.