Tunga penetrans (chigoe flea or jigger) 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. It is native to Central and South America, and has been inadvertently introduced by humans to sub-Saharan Africa. At 1 mm long, T. penetrans is the smallest known flea. Synonyms for Tunga penetrans include Sarcopsylla penetrans, Pulex penetrates, and many others The names "chigoe flea" and "jigger" cause it to be confused with the similar-sounding chigger, (Trombiculidae or harvest mite).
Breeding females burrow into exposed skin on the feet of mammals and remain there for two weeks while developing eggs, during which time they swell dramatically, sometimes causing intense irritation, a condition called tungiasis. 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, dangerous complications can occur including secondary infections, loss of toenails, and toe deformation. These seem to be commonplace especially where heavy infestations combine with unsanitary conditions and poverty.
The parasitic flea lives in soil and sand, and feeds intermittently on warm-blooded hosts, such as humans and cattle. Males leave the host after a blood meal like other fleas, but the female flea burrows head-first into the host's skin, leaving the caudal tip of its abdomen visible through an orifice in a skin lesion. This orifice allows the flea to defecate while feeding from blood vessels that provide oxygen for respiration as well. It lives in the cutaneous and subcutaneous dermal layer. Over the next two weeks, its abdomen swells with up to several hundred to a thousand eggs, which it releases through the caudal orifice to fall to the ground when ready to hatch. The flea then dies and is often the cause of infection as the body rots under the thick scales its body chemistry created to protect it. The eggs mature into adult fleas within three to four weeks and the process begins anew.
Since the fleas spend most of their time on the ground, tungiasis lesions are usually on the feet; however, like most fleas they are capable of jumping up 20 cm, and lesions may occur on any part of the body, favoring regions of soft skin such as between the toes. 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 vessels. Depending on the exact site, this can cause sensations ranging from mild irritation to serious discomfort.
|In Lingala-speaking areas||liyanzi (singular) or mayanzi (plural)|
|In Brazil||bicho-de-pé (foot bug)|
|In Spanish||pique (due to the itching and burning sensation it produces)|
|in Central America, Peru, Colombia and Ecuador||nigua|
|In Kinyarwanda and Kirundi||ivunja or imvunja (singular) or amavunja (plural)|
|Wikimedia Commons has media related to Tunga penetrans.|
- World Health Organization, a WHO bulletin containing the article, "Epidermal parasitic skin diseases: a neglected category of poverty-associated plagues."
- Ahadi Kenya Trust is a non-governmental organization founded in 2007 whose major activity is to eradicate jiggers.
- Kingdom Driven Ministries, a US-based missionary organization with specific emphasis on East Africa, coordinates several medical initiatives, including jigger treatment.
- Rise Up Society, a registered charitable organization in Kenya, works to improve the plight of the poor in rural communities through its economic and health initiatives. Its jigger eradication program, Kill the Jigger, treats patients, fumigates living quarters, provides shoes, and educates local leaders.
- Sole Hope, registered in the United States as a 501(c)(3) charity, aims to prevent jiggers (and other diseases that enter through the foot) throughout Uganda. In addition to providing shoes to individuals, Sole Hope also trains local men and women to make shoes, thus providing them with a useful trade through which they can earn income.
- Whisper, a registered charity in England and Wales, runs a jigger treatment and education program in Uganda, as a part of their broader mission to benefit children in the region.
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- Linardi, Pedro Marcos; Beaucournu, Jean-Claude; de Avelar, Daniel Moreira; Belaz, Sorya (2014). "Notes on the genus Tunga (Siphonaptera: Tungidae) II – neosomes, morphology, classification, and other taxonomic notes". Parasite 21: 68. doi:10.1051/parasite/2014067. ISSN 1776-1042. PMID 25514594.
- Kara, Shamilla (25 Apr 2013). "Whisper resuscitates hope for children in jigger-infested communities". New Vision. Retrieved 22 February 2015.