Chigoe flea
Encyclopedia
The chigoe flea or jigger (Tunga penetrans) is a parasitic arthropod
found in most tropical and sub-tropical climates, not to be confused with the larval form of Trombiculidae
(called chiggers) found in more temperate climates. In Brazil
, the parasite is referred to as bicho-de-pé (foot bug). At 1 mm long, the chigoe flea is the smallest known flea
. Breeding female chigoes burrow into exposed skin on the feet of mammals and remain there for two weeks while developing eggs, sometimes causing intense irritation. After this point, the skin lesion looks like a 5 to 10 mm blister with a central black dot, which are the flea's exposed hind legs, respiratory spiracles and reproductive organs.
If the flea is left within the skin, infection and/or other dangerous complications can occur, although they are relatively rare.
The parasitic flea lives in soil
and sand
, and feeds intermittently on warm-blooded hosts such as humans, cattle, sheep, dogs, mice, and other animals. In order to reproduce, the female flea burrows head-first into the hosts' skin, often leaving the caudal tip of its abdomen
visible through an orifice in a skin lesion
. This orifice allows the chigoe flea to breathe and defecate while feeding on blood vessel
s in the cutaneous and subcutaneous dermal layer. In the next two weeks, its abdomen swells with up to several dozen egg
s which it releases through the caudal orifice to fall to the ground when ready to hatch. The flea then dies and is sloughed off with the host's skin. Within the next three to four days, the eggs hatch and mature into adult fleas within three to four weeks.
Infections are almost always on the foot of the host. During the first day or two of infection the host may feel an itching or irritation which then passes as the area around the flea calluses and becomes insensitive. As the flea's abdomen swells with eggs later in the cycle, the pressure from the swelling may press neighbouring nerves or blood vessel
s. Depending on the exact site, this can cause sensations ranging from mild irritation to serious discomfort.
It has been written that the explanation for the preponderance of tungiasis lesions on the toes is because chigoe flea is a poor jumper, attaining only a high of 20 cm http://www.dermato.med.br/publicacoes/artigos/2007Tungiasis-and-Myiasis.pdf. But this idea is not correct for many reasons. First of all, while chigoe flea can jump up only 20 cm, its infamous and bigger cousin Flea
which is the vector of bubonic plague and well known for its jumping ability, can jump up only 18 cm; the chigoe flea should be considered a champion jumper, not a poor one. And the jumping ability cannot explain why hands are the second most affected body part. The occurrence of tungiasis lesions on the toes, between them, on the soles can easily explained by the fact that most of the victims are poor and walk barefoot (or wear cheap floppies as seen in some photos of the condition). Because the front part of the feet, which are the toes hit the ground first, the fleas have more opportunity to latch on there. They also get trapped between the toes, or under the soles when the victims stand still. More lesions on the hands are seen in children because they play in the sand or dusty ground. Other common ectopic sites of infestation are the elbows, buttocks and the genital area (gluteal area in scientific publications) and this can be explained by the habit of sitting on bare ground while leaning back on the elbows.
A study published in 2006 http://cat.inist.fr/?aModele=afficheN&cpsidt=17508421 has concluded that "Contrary to common belief, a protective effect of frequent use of closed footwear could not be demonstrated".
The chigoe is sometimes called a "chigger," a term also used for the harvest mite
in North America
.
In Lingala speaking areas it is commonly known as "liyanzi" (singular) or "mayanzi" (plural).
In Spanish, the chigoe is commonly known as "pique" due to the itching and burning sensation that it produces; in Colombia it is known as "nigua". In Guarani Guarani
, the national language of Paraguay, it is known as tũ.
In Kinyarwanda and Kirundi
, they are known as "ivunja/imvunja" (Singular) or "Amavunja" (Plural).
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
found in most tropical and sub-tropical climates, not to be confused with the larval form of Trombiculidae
Trombiculidae
Trombiculidae is a family of mites called trombiculid mites Trombiculidae is a family of mites called trombiculid mites Trombiculidae is a family of mites called trombiculid mites (also called berry bugs; harvest mites; red bugs; scrub-itch mites; and aoutas. In their larval stage, those...
(called chiggers) found in more temperate climates. In Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, the parasite is referred to as bicho-de-pé (foot bug). At 1 mm long, the chigoe flea is the smallest known flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
. Breeding female chigoes burrow into exposed skin on the feet of mammals and remain there for two weeks while developing eggs, sometimes causing intense irritation. After this point, the skin lesion looks like a 5 to 10 mm blister with a central black dot, which are the flea's exposed hind legs, respiratory spiracles and reproductive organs.
If the flea is left within the skin, infection and/or other dangerous complications can occur, although they are relatively rare.
The parasitic flea lives in soil
Soil
Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...
and sand
Sand
Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...
, and feeds intermittently on warm-blooded hosts such as humans, cattle, sheep, dogs, mice, and other animals. In order to reproduce, the female flea burrows head-first into the hosts' skin, often leaving the caudal tip of its abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
visible through an orifice in a skin lesion
Lesion
A lesion is any abnormality in the tissue of an organism , usually caused by disease or trauma. Lesion is derived from the Latin word laesio which means injury.- Types :...
. This orifice allows the chigoe flea to breathe and defecate while feeding on blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s in the cutaneous and subcutaneous dermal layer. In the next two weeks, its abdomen swells with up to several dozen egg
Egg (biology)
An egg is an organic vessel in which an embryo first begins to develop. In most birds, reptiles, insects, molluscs, fish, and monotremes, an egg is the zygote, resulting from fertilization of the ovum, which is expelled from the body and permitted to develop outside the body until the developing...
s which it releases through the caudal orifice to fall to the ground when ready to hatch. The flea then dies and is sloughed off with the host's skin. Within the next three to four days, the eggs hatch and mature into adult fleas within three to four weeks.
Infections are almost always on the foot of the host. During the first day or two of infection the host may feel an itching or irritation which then passes as the area around the flea calluses and becomes insensitive. As the flea's abdomen swells with eggs later in the cycle, the pressure from the swelling may press neighbouring nerves or blood vessel
Blood vessel
The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and...
s. Depending on the exact site, this can cause sensations ranging from mild irritation to serious discomfort.
It has been written that the explanation for the preponderance of tungiasis lesions on the toes is because chigoe flea is a poor jumper, attaining only a high of 20 cm http://www.dermato.med.br/publicacoes/artigos/2007Tungiasis-and-Myiasis.pdf. But this idea is not correct for many reasons. First of all, while chigoe flea can jump up only 20 cm, its infamous and bigger cousin Flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
which is the vector of bubonic plague and well known for its jumping ability, can jump up only 18 cm; the chigoe flea should be considered a champion jumper, not a poor one. And the jumping ability cannot explain why hands are the second most affected body part. The occurrence of tungiasis lesions on the toes, between them, on the soles can easily explained by the fact that most of the victims are poor and walk barefoot (or wear cheap floppies as seen in some photos of the condition). Because the front part of the feet, which are the toes hit the ground first, the fleas have more opportunity to latch on there. They also get trapped between the toes, or under the soles when the victims stand still. More lesions on the hands are seen in children because they play in the sand or dusty ground. Other common ectopic sites of infestation are the elbows, buttocks and the genital area (gluteal area in scientific publications) and this can be explained by the habit of sitting on bare ground while leaning back on the elbows.
A study published in 2006 http://cat.inist.fr/?aModele=afficheN&cpsidt=17508421 has concluded that "Contrary to common belief, a protective effect of frequent use of closed footwear could not be demonstrated".
Synonyms
- Sarcopsylla penetrans
- Pulex penetrans
The chigoe is sometimes called a "chigger," a term also used for the harvest mite
Harvest mite
Trombicula is a genus of harvest mites in the Trombiculidae family. In their larval stage, they attach to various animals, including humans, and feed on skin, often causing itching...
in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
In Lingala speaking areas it is commonly known as "liyanzi" (singular) or "mayanzi" (plural).
In Spanish, the chigoe is commonly known as "pique" due to the itching and burning sensation that it produces; in Colombia it is known as "nigua". In Guarani Guarani
Guaraní language
Guaraní, specifically the primary variety known as Paraguayan Guaraní , is an indigenous language of South America that belongs to the Tupí–Guaraní subfamily of the Tupian languages. It is one of the official languages of Paraguay , where it is spoken by the majority of the population, and half of...
, the national language of Paraguay, it is known as tũ.
In Kinyarwanda and Kirundi
Kirundi
Kirundi, also known as Rundi, is a dialect of the Rwanda-Rundi language spoken by some 8.7 million people in Burundi and adjacent parts of Tanzania and Congo-Kinshasa, as well as in Uganda. It is the official language of Burundi...
, they are known as "ivunja/imvunja" (Singular) or "Amavunja" (Plural).
External links
- http://www.afronets.org/archive/200110/msg00058.php
- Periungual Tungiasis Muehlstaedt M (2008) Images in clinical medicine. Periungual tungiasis. N Engl J Med 359(24):e30.
- http://www.feedthechildren.org.uk/pages/JiggersCampaignPage.shtml Stamp Out Jiggers Campaign by Feed The Children UK, Supported by The Hoosiers.