Tunga penetrans

Etiology

Tungiasis is caused by Tunga penetrans , a 1-mm long sand flea, also known as the chigoe or jigger flea, which infests swine, human, and other mammalian hosts. The fertilized female flea burrows into the skin of the host, where she resides within the stratum corneum of the epidermis, feeds on blood, and gradually enlarges to the size of a small pea. The posterior end of the flea remains in contact with the air for respiration and discharge of ova. The eggs fall to the ground and develop into larvae, which then form a cocoon and emerge as adults after 10 days. Over the course of a few weeks, the female discharges 100 or more eggs. She then dies and is sloughed with the host's stratum corneum.

Durante siete a diez días expulsa entre 150 a 200huevos, muriendo posteriormente y permaneciendo como residente permanente.

Los adultos viven en el ambiente (arena o polvo), en áreas de criaderos de ganado: porcino, vacuno; la hembra fecundada penetra por la piel de tejido cutáneo o subcutáneo de su huésped, invade el tejido hasta encontrar un canal sanguíneo para alimentarse, ingurgita su abdomen y termina como una bola, incrementando su volumen de 5-10 veces su tamaño original, lacabeza está en el interior del tejido y queda expuesta el pigidio hacia fuera para la respiración.

The chigoe flea, Tunga penetrans. The flea is also referred to as the jigger, nigua, chica, pico, pique or suthi.

Life Cycle

Eggs are shed by the gravid female into the environment . Eggs hatch into larvae in about 3-4 days and feed on organic debris in the environment. Tunga penetrans has two larval stages before forming pupae . The pupae are in cocoons that are often covered with debris from the environment (sand, pebbles, etc). The larval and pupal stages take about 3-4 weeks to complete. Afterwards, adults hatch from pupae and seek out a warm-blooded host for blood meals. Both males and females feed intermittently on their host, but only mated females burrow into the skin (epidermis) of the host, where they cause a nodular swelling . Females do not have any specialized burrowing organs, and simply claw into the epidermis after attaching with their mouthparts. After penetrating the stratum corneum, they burrow into the stratum granulosum, with only their posterior ends exposed to the environment . The female fleas continue to feed and their abdomens extend up to about 1 cm. Females shed about 100 eggs over a two-week period, after which they die and are sloughed by the host’s skin. Secondary bacterial infections are not uncommon with tungiasis.

Geographic Distribution

Tunga penetrans is distributed in tropical and subtropical regions of the world, including Mexico to South America, the West Indies and Africa. The fleas normally occur in sandy climates, including beaches, stables and farms.

Clinical Presentation

The initial burrowing by the gravid females is usually painless; symptoms, including itching and irritation, usually start to develop as the females become fully-developed into the engorged state. Inflammation and ulceration may become severe, and multiple lesions in the feet can lead to difficulty in walking. Secondary bacterial infections, including tetanus and gangrene, are not uncommon with tungiasis.

1. Малая медицинская энциклопедия. — М.: Медицинская энциклопедия. 1991—96 гг. 2. Первая медицинская помощь. — М.: Большая Российская Энциклопедия. 1994 г. 3. Энциклопедический словарь медицинских терминов. — М.: Советская энциклопедия. — 1982—1984 гг .

Смотреть что такое «Tunga penetrans» в других словарях:

Tunga penetrans — puce chique … Wikipédia en Français

Tunga penetrans — Weibchen nach operativer Entfernung Systematik Klasse: Insekten (Insecta) … Deutsch Wikipedia

Tunga penetrans — puce chique … Wikipédia en Français

Tunga penetrans —   Tunga penetrans … Wikipedia Español

Tunga penetrans — chigger chigger n. 1. a small tropical flea (, formerly ); same as . [Also spelled .] Syn: chigoe, chigoe flea, . [WordNet 1.5] 2. a larval mite of the family that … The Collaborative International Dictionary of English

Tunga penetrans — chigger chigger n. 1. a small tropical flea (, formerly ); same as . [Also spelled .] Syn: chigoe, chigoe flea, . [WordNet 1.5] 2. a larval mite of the family that … The Collaborative International Dictionary of English

Tunga penetrans — Jigger Jig ger (j[i^]g g[ e]r), n. [A corrupt. of chigre.] 1. (Zo[ o]l.) A species of flea (, or , or ), which burrows beneath the skin; called also . See . [1913… … The Collaborative International Dictionary of English

Tunga penetrans — Chigoe Chig oe, Chigre Chig re, n. [Cf. F. chigue, perh. fr. Catalan chic small, Sp. chico; or of Peruvian origin.] (Zo[ o]l.) A species of flea (, formerly ), common in the West Indies and South America, which… … The Collaborative International Dictionary of English

Tunga penetrans — noun small tropical flea; the fertile female burrows under the skin of the host including humans • Syn: ↑chigoe, ↑chigger, ↑chigoe flea • Hypernyms: ↑flea • Member Holonyms: ↑Tunga, ↑genus Tunga … Useful english dictionary

Tunga penetrans — A member of the flea family, Tungidae, commonly known as chigger flea, sand flea, chigoe, or jigger; the minute female penetrates the skin, frequently under the toenails; as she becomes distended with eggs to about pea size, a painful ulc … Medical dictionary

Tunga penetrans — (син.: блоха песчаная, блоха проникающая) вид блох сем. Fungidae, представители которого являются эктопаразитами; оплодотворенные самки переходят на внутрикожное паразитирование, гл. обр. в подногтевых и межпальцевых пространствах ног и в области … Большой медицинский словарь

Síntomas y diagnóstico

La morbilidad aguda y crónica de la tungiasis es producto de la reacción inflamatoria que aparece alrededor de las pulgas enquistadas en la dermis, exacerbada por la sobreinfección bacteriana. Durante la fase aguda, el eritema, el edema, la descamación, el dolor y el picor son constantes. El prurito induce a rascarse, lo que a su vez facilita la sobreinfección bacteriana. También son frecuentes los abscesos, a veces de gran tamaño.

Aunque los pies son el lugar de infestación más habitual, esta puede ocurrir en cualquier parte del cuerpo. También se han notificado lesiones ampollares. Las complicaciones crónicas pueden ser fisuras, úlceras, linfangitis, linfedema, neuritis ascendente, deformación, pérdida de uñas y necrosis de tejidos, que pueden ocasionar dolor, incapacidad, deformidad y mutilación de los pies y una forma característica de caminar.

El diagnóstico se basa en las etapas de desarrollo de la enfermedad; por lo general, se observa una pápula blanquecina, de tamaño variable, con un punto central oscuro que con el tiempo pasa a ser completamente negro, etapa en que el parásito muere. Normalmente, en las zonas donde la enfermedad es endémica, las personas afectadas (incluso los niños) saben si la tienen.

Prevention and control

The regular application of a repellent based on coconut oil effectively prevents the fleas from penetrating the skin. When the repellent is applied twice daily on the feet, tungiasis-associated morbidity rapidly decreases and approaches zero after 8–10 weeks 4 . Even if applied intermittently, the reduction of morbidity is significant.

A long-lasting reduction of incidence and of tungiasis-associated morbidity can only be achieved through an approach integrating behavioural change, the environment, animal reservoirs and humans.