''Argas persicus'', also known as fowl tick or poultry tick, is a small soft-bodied

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 ...

that is found primarily on domestic fowl such as chickens, ducks, and geese. It was first recorded by

Lorenz Oken Lorenz Oken (1 August 1779 – 11 August 1851) was a German naturalist, botanist, biologist, and ornithologist. Oken was born Lorenz Okenfuss (german: Okenfuß) in Bohlsbach (now part of Offenburg), Ortenau, Baden, and studied natural history and ...

in 1818 in Mianeh,

Persia Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkmeni ...

, and named ''Rhynochoprion persicum''. ''Argas persicus'' appears yellowish-brown when starved and slatey-blue when engorged. They are found on an animal host, in cracks and crevices of buildings or in nests. They are also carriers of the spirochete bacteria ''

Borrelia anserina ''Borrelia anserina'' is a helical spirochete bacterium with dimensions around 8-20/0,2-0,3 μm and with five to eight spirals. Their mobility is very high. ''B. anserina'' can be colored with the May Grunwald-Giemsa method. Cultivation In mic ...

'' which causes avian spirochetosis, one of the most severe diseases affecting the poultry industry. In addition to domestic fowl, ''A. persicus'' may also feed on humans, although an immunity has been acquired by some individuals.

Distribution

The fowl tick is distributed worldwide but does tend to prefer a warmer climate. The lower United States especially sees a large distribution of this soft bodied tick due to the warm climate.

Life Cycle

Argasid (soft) ticks have a multihost life cycle meaning it has two or more nymphal stages that each require a blood meal. Mating and the laying of eggs occurs off the host and in sheltered areas such as bird nests. Six-legged larvae hatch from the eggs in the chosen sheltered area. Once a suitable host is found in the vicinity, they begin to feed for a few hours to a few days. The larvae finish feeding and leaves the host for an area of shelter. The larvae then molt to become the first nymph stage. The first nymphs stage then move onto the second host to feed. This second host may be the same individual as the first and is likely the same species. The first stage of nymphs transforms to the next nymph stage when it leaves the host and molts once more. These nymph stages can reach up to seven stages. After the last nymph stage, it leaves the host to molt into an adult. The adults can continue to feed on the host feeding quickly and detaching from the host after each blood meal. Females often lay eggs after each meal when off the host.

Pathogen Transmission

''A. persicus'' is a natural reservoir for ''B. anserina'' as it helps these spirochetes survive longer.

West Nile virus West Nile virus (WNV) is a single-stranded RNA virus that causes West Nile fever. It is a member of the family ''Flaviviridae'', from the genus ''Flavivirus'', which also contains the Zika virus, dengue virus, and yellow fever virus. The virus ...

was also found to be able to infect the tick when feeding on an infected membrane. This was tested using artificial inoculation. If the pathogen infects humans due to ''A. persicus'', it would likely be as an incidental host but humans may be fed upon by any of the stages.

Disease and Symptoms

Avian Spirochetosis

This disease is

sepsis Sepsis, formerly known as septicemia (septicaemia in British English) or blood poisoning, is a life-threatening condition that arises when the body's response to infection causes injury to its own tissues and organs. This initial stage is follo ...

by ''B. anserina'' being transmitted in ''A. persicus'' saliva. The spirochete can be seen in blood samples taken from infected birds. Young birds appear to be especially susceptible to the larvae of ''A. persicus'' due to not having been exposed to it before. Although domestic birds do not fully develop immunity against the paralysis inducing toxins produced, a weak protective mechanism may result from having been infected. Symptoms of avian spirochetosis include drop in egg production, depression,

polydipsia Polydipsia is excessive thirst or excess drinking.Porth, C. M. (1990). ''Pathophysiology: Concepts of altered health states''. Philadelphia: J.B. Lippincott Company. The word derives from the Greek () "very thirsty", which is derived from (, "mu ...

(increased thirst), drowsiness, anorexia, loss of appetite, green diarrhea, ruffled feathers, pale combs, weight loss, paralysis of the legs and wings (flaccid paralysis), and abrupt death. Before death, the bird tends to become recumbent or begins to lie down stretched out. This is especially true when heavily infested with the larval stage of ''A. persicus''.

Fowl Tick Infection and Tick Paralysis

Tick paralysis is included in avian spirochetosis and appears in the same fashion. The flaccid paralysis ascends throughout the body. Incoordination first occurs followed by paralysis of the hind limbs, forelimbs, and then leads to respiratory distress and failure. Death then follows. Blood loss during infection could occur as well and result in clinical anemia.

Treatment

Controlling the larvae is important as it acts as a vector for ''B. anserina''. Repeated treatments with

malathion Malathion is an organophosphate insecticide which acts as an acetylcholinesterase inhibitor. In the USSR, it was known as carbophos, in New Zealand and Australia as maldison and in South Africa as mercaptothion. Pesticide use Malathion is a pesti ...

spray helps to reduce the ticks and helps the birds recover.

Penicillin Penicillins (P, PCN or PEN) are a group of β-lactam antibiotics originally obtained from ''Penicillium'' moulds, principally '' P. chrysogenum'' and '' P. rubens''. Most penicillins in clinical use are synthesised by P. chrysogenum using ...

injections appear to have no effect in treatment of the bacteria. The elimination of tick larvae is key to reversing the effects of avian spirochetosis. Hydration is also extremely important as death most often results due to dehydration from prolonged paralysis.Rosenstein, M. "Paralysis in Chickens Caused by Larvae of the Poultry Tick, Argas Persicus." Avian Diseases 20.2 (1976): 407-09. JSTOR. American Association of Avian Pathologists, Inc. Web. 15 Apr. 2017.