''Leucocytozoon caulleryi'' is a species of the genus ''Leucocytozoon'', a genus of parasitic alveolates. This species has both insect (''

Culicoides ''Culicoides'' is a genus of biting midges in the family Ceratopogonidae. There are over 1000 species in the genus,Connelly, C. RBiting midges: ''Culicoides'' spp.Featured Creatures, Entomology and Nematology Department, University of Florida IF ...

'' species) and vertebrate (

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweig ...

s) hosts.

Description

History

This species was originally described by Mathis and Leger in 1909. The species was also described by Akiba in Japan in 1958. A second species - ''Leucocytozoon schufneri'' - was described by Prowazek in 1912 also in the chicken. This is now considered to be a synonym. This species has been classified into the subgenus '' Akiba'' because of its vector: other species in the genus are transmitted by species of the genus ''

Simulium ''Simulium'' is a genus of black flies, which may transmit diseases such as onchocerciasis (river blindness). It is a large genus with several hundred species, and 41 subgenera. The flies are pool feeders. Their saliva, which contains antic ...

''.

Life cycle

The parasite is transmitted by the bite of its vector. On infection of a vertebrate host, the parasites enter the blood stream and spread through the body. They invade the endothelial cells in a number of organs. These grow into multinucleated masses - megaloschizonts. This first round of schizonts give rise to the first generation of merozoites. This first generation of merozoites invade new endothelial cells and give rise to a second generation of schizonts. After a number of cell divisions these in turn give rise to the second generation of

merozoite Apicomplexans, a group of intracellular parasites, have life cycle stages that allow them to survive the wide variety of environments they are exposed to during their complex life cycle. Each stage in the life cycle of an apicomplexan organism is ...

s which in their turn infect

erythrocyte Red blood cells (RBCs), also referred to as red cells, red blood corpuscles (in humans or other animals not having nucleus in red blood cells), haematids, erythroid cells or erythrocytes (from Greek ''erythros'' for "red" and ''kytos'' for "holl ...

s and leukocytes. Within the erythrocytes or leukocytes, the merozoites develop into

gametocyte A gametocyte is a eukaryotic germ cell that divides by mitosis into other gametocytes or by meiosis into gametids during gametogenesis. Male gametocytes are called ''spermatocytes'', and female gametocytes are called ''oocytes''. Development ...

s. Once ingested by a vector male and female gametocytes fuse and give rise to a zygote. The zygote invades the body of the vector, undergoes a series of cell divisions resulting in motile sporozoites that invade the salivary glands of the vector. Early schizonts are spherical or ovoid and 30-35

micrometers The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

(µm) in diameter.Isobe T, Akiba K (1900) Early schizonts of ''Leucocytozoon caulleryi''. J Parasitol 76(4):587-589 Gametocytes are round and measure 15.0 to 15.5 µm in diameter.

Geographic distribution

This species is found in Japan,

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a transcontinental country located mainly in Central Asia and partly in Eastern Europe. It borders Russia to the north and west, China to the east, Kyrgyzstan to the southeast, Uzbeki ...

Malaysia Malaysia ( ; ) is a country in Southeast Asia. The federation, federal constitutional monarchy consists of States and federal territories of Malaysia, thirteen states and three federal territories, separated by the South China Sea into two r ...

, the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

Singapore Singapore (), officially the Republic of Singapore, is a sovereign island country and city-state in maritime Southeast Asia. It lies about one degree of latitude () north of the equator, off the southern tip of the Malay Peninsula, bor ...

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia, at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the nort ...

and

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is b ...

Clinical features and host pathology

This species infects chickens (''

Gallus gallus domesticus The chicken (''Gallus gallus domesticus'') is a domesticated junglefowl species, with attributes of wild species such as the grey and the Ceylon junglefowl that are originally from Southeastern Asia. Rooster or cock is a term for an adult ...

''), guinea fowl and pheasants. After infection schizongony occurs in the

adrenal The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex whic ...

brain A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a ve ...

, intestine,

kidney The kidneys are two reddish-brown bean-shaped organs found in vertebrates. They are located on the left and right in the retroperitoneal space, and in adult humans are about in length. They receive blood from the paired renal arteries; blo ...

liver The liver is a major organ only found in vertebrates which performs many essential biological functions such as detoxification of the organism, and the synthesis of proteins and biochemicals necessary for digestion and growth. In humans, it ...

, muscles,

ovaries The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. T ...

pancreas The pancreas is an organ of the digestive system and endocrine system of vertebrates. In humans, it is located in the abdomen behind the stomach and functions as a gland. The pancreas is a mixed or heterocrine gland, i.e. it has both an en ...

spleen The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes .

thymus The thymus is a specialized primary lymphoid organ of the immune system. Within the thymus, thymus cell lymphocytes or ''T cells'' mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. ...

and

trachea The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air- breathing animals with lungs. The trachea extends from the ...

. Typical pathology includes the presence of the schizonts and the surrounding granulomata, haemorrhages, oedema and pressure atrophy in the oviducts. Infected chickens are anaemic, have pale combs and diarrhoea. Egg production may be reduced and the egg shells may be softer than normal. Chickens who survive the infection appear to be resistant to re infection. A vaccine based on a recombinant protein is available.Ito A, Gotanda T (2004) Field efficacy of recombinant R7 vaccine against chicken leucocytozoonosis. J Vet Med Sci 66(5):483-487 This disease is also known as

Bangkok Bangkok, officially known in Thai as Krung Thep Maha Nakhon and colloquially as Krung Thep, is the capital and most populous city of Thailand. The city occupies in the Chao Phraya River delta in central Thailand and has an estimated populati ...

haemorrhagic disease.

Vectors

Known vectors of this parasite include '' Culicoides arakawae'' Arakawa 1910.

Diagnosis

Blood smears can be performed to identify the parasite in the red blood cells.

ELISA The enzyme-linked immunosorbent assay (ELISA) (, ) is a commonly used analytical biochemistry assay, first described by Eva Engvall and Peter Perlmann in 1971. The assay uses a solid-phase type of enzyme immunoassay (EIA) to detect the presen ...

testing can be used for antigen or antibody testing.''Leucocytozoon caulleryi''
reviewed and published by

WikiVet WikiVet is a wiki of veterinary content based on the MediaWiki platform. The website is a collaborative initiative between various veterinary schools, and its content covers the entire veterinary curriculum. WikiVet is part of the WikiVet Educatio ...

, accessed 12 October 2011.

Treatment and prevention

Treatment is usually ineffective. In-feed

pyrimethamine Pyrimethamine, sold under the brand name Daraprim among others, is a medication used with leucovorin (leucovorin is used to decrease side effects of pyrimethamine; it does not have intrinsic anti-parasitic activity) to treat the parasitic dise ...

and

sulfadimethoxine Sulfadimethoxine (or sulphadimethoxine, trade names Di-Methox or Albon) is a long-lasting sulfonamide antimicrobial medication used in veterinary medicine. It is used to treat many infections, including respiratory, urinary tract, enteric, and s ...

can help prevent the disease. Prevention is by control of the infecting vectors but is often difficult to implement.

References

{{Taxonbar, from=Q4700880 Haemosporida Parasites of Diptera Culicoides Parasites of birds