Chigoe Flea – Tunga penetrans
The Female Jigger is an Unpleasant Skin Parasite of the Tropics
Chigoe Fleas (Tunga penetrans) are unlike other familiar fleas because they burrow into the skin, causing pain and sometimes serious infection.
Tunga penetrans
Tunga penetrans is a flea. It looks a lot like other fleas except that it is very small – adults are about one millimeter long. T. penetrans is known by many other names including chigoe flea, jigger, chigger, and sand flea. The scientific species name – penetrans – is arguably the most descriptive: the female flea penetrates the skin and makes her home beneath the surface. She causes misery out of all proportion to her size.
Why the female chigoe burrows
Chigoes live in sandy soil in the tropics – on sandy beaches and in other warm sandy soil in Central America and South America, the West Indies, Africa, and India. In sand and soil, eggs hatch and larvae develop to adults, feeding on decaying organic material. When the adult female is ready to mate and lay eggs, she seeks out a plentiful food supply, a host where she can remain, feeding and producing eggs. Her favored location is under the skin of a mammal.
The Tunga penetrans lesion
The unwary human that walks barefoot, and perhaps sits down or handles the soil where the female T. penetrans is waiting, will shortly notice irritation developing around the edges of fingernails, between the digits, or in creases and folds in the skin. The tiny female has burrowed head first into the skin and is feeding. She has probably mated and is becoming engorged, swelling as she feeds and begins to produce eggs. Her legs are degenerating - they are no longer needed.
The cavity in which the gravid female rests will grow to about the size of a pea, filled with flea, eggs, and hatched larvae. It retains a tiny opening to the outside world. Larvae exit through the opening to drop to the ground, develop, and start the cycle over again. As the tissue damage around the lesion becomes more severe, unhatched eggs may be released as well.
For the host, the embedded flea causes a painful inflamed swollen lesion. the wound is susceptible to infection by other organisms, and if there are many fleas embedded, the health consequences for the host can be serious, ranging from local infection through loss of digits or limbs and rarely even death (usually as a consequence of serious secondary bacterial infection). For those with access to good medical care, surgical removal of the flea and cleansing of the wound will end the agony.
Many people confuse Tunga penetrans with chigger mites, the parasitic larvae of trombiculid mites. Chigger mites are found in both the tropics and temperate climates and though they are quite different from chigoe fleas, they can cause comparable misery. Read about chigger mites.
View pictures of Tunga penetrans and the lesions.
Related articles:
Scabies mite – Sarcoptes scabiei
Sources:
Garcia, Lynne S. and David Bruckner. Diagnostic Medical Technology, 3rd. Ed. Washington: ASM Press, 1997.
Knutson, Roger M. Furtive Fauna: A Field Guide to the Creatures Who Live on Us. New York: Penguin Books, 1992.
Schmidt, Gerald D. and Larry S. Roberts. Foundations of Parasitology 6th ed. Boston: McGraw Hill, 2000.
