Background
Tungiasis is an infestation by the burrowing flea Tunga penetrans or related species.[1] The flea has many common names, being known in various locations as the chigger flea, sand flea, chigoe, jigger, nigua, pigue, or le bicho de pe (see the image below). Painful infections with T penetrans can cause significant morbidity. (See Etiology.)
This illustration shows some of the identifying morphologic characteristics of the chigoe flea, Tunga penetrans. Courtesy of the CDC. Tungiasis was first reported in crewmen who sailed with Christopher Columbus. The flea is indigenous to the West Indies/Caribbean/Central America region, but it has spread to Africa, India, Pakistan, and South America. Tungiasis is rarely diagnosed in North America, but it should no longer be obscure to physicians because of increasing international travel to tropical destinations. (See Epidemiology, Clinical, and Workup.)[2]
To reproduce, the flea requires a warm-blooded host. In addition to humans, reservoir hosts include pigs, dogs, cats, cattle, sheep, horses, mules, rats, mice, and other wild animals (see the image below). (See Etiology.)[3, 4, 5, 6]
Life cycle of Tunga penetrans - Fortaleza stages included. Patient education
Travelers to affected countries must be advised to wear shoes (not sandals) when walking along sandy areas in affected regions and to refrain from sitting or lying in the sand.
Etiology
The main habitat for T penetrans is warm, dry soil and sand of beaches, stables, and stock farms. Upon contact, the flea invades unprotected skin. The most common site of involvement is the feet (interdigital skin and subungual area). The flea has limited jumping ability.
Both the male and the nonfertilized female flea feed intermittently on warm-blooded hosts, but only the female flea can produce the typical skin lesion of tungiasis.[7] . Once impregnated, the female flea anchors herself to the skin by using biting mouthparts and burrows into the epidermis of the host near the plantar surfaces of the foot,[8] in the webbing between the toes, and around the periungual region. Because the process is painless, a keratolytic enzyme may be involved.
The flea expands, often reaching 1 cm in diameter. The head is down into the upper dermis, feeding from blood vessels, while the caudal tip of the abdomen is at the skin surface, often forming a punctum or an ulceration (see the images below). The flea breathes through this opening. In many cases, this is described as a white patch with a black dot. Very heavy infestation may cause ulceration and fibrosis that may result in secondary infections, such as bacteremia, tetanus, lymphangitis, and gas gangrene.[9]
Scanning electron micrograph of flea 6 hours after beginning of penetration. The penetration is almost completed; only the last abdominal segments protrude through the skin (x240). 
Scanning electron micrograph of flea in stage 2. The rear end, the genital opening, and the 4 pairs of stigmata form a miniature cone, which towers above the crater caused by pushing in abdominal segments 7 and 8 (x190). 
Scanning electron micrograph of flea on day 3 after penetration. The hypertrophic zone between abdominal segments 2 and 3 is gaining a bulging shape and looks like a life-belt (x100). 
Scanning electron micrograph of flea on day 8 after penetration. The hypertrophy zone has taken the shape of a sphere. The 3 parts of abdominal segment 2 are completely bent apart. Together with the newly developed, crescent-shaped chitinous clasps, the anterior part of the flea looks like a 3-leafed clover (x32). Over 1-2 weeks, more than 100 eggs, which fall to the ground, are individually released from the exposed orifice. Afterwards, the flea dies and is slowly sloughed by the host. The eggs hatch on the ground in 3-4 days, go through larval and pupal stages and become adults in 2-3 weeks. The complete life cycle lasts approximately 1 month.
The major risk factor for exposure to T penetrans is failure to wear shoes when walking in sand in an area with active infestation. Wearing shoes and not sitting or lying in the sand are the most important steps to reduce infection risk.
Epidemiology
Occurrence in the United States
The incidence of tungiasis is unknown because it is not a reportable disease. As of 2000, only 20 cases had been reported in the United States, with 15 of them being reported prior to 1989.[10, 11, 12, 13] Since 2000, sporadic cases have been reported in the United States.[14] All of these cases were imported from outside of the United States.
International occurrence
Tungiasis is potentially endemic in 88 countries worldwide.[15] Approximately 45.2% of a Nigerian community in Lagos State was observed to be infected, with most of the cases occurring in children between the ages of 5 and 14 years.[16] In a traditional fishing village in northeastern Brazil, the overall prevalence was 51%.[17, 18] In a village in rural Haiti, nearly 75% of the population was observed to have tungiasis lesions.[19] Six percent of the patients visiting a travel-associated dermatosis clinic in Paris had tungiasis.[5]
Race-, sex-, and age-related demographics
No racial predisposition is apparent. Infection rates among native inhabitants of developing countries, however, are much higher than among visitors.
In endemic regions, such as Trinidad, males were found to be consistently more likely than females to have an infestation. Males also had higher chigoe flea burdens, with about twice the number of fleas detected per subject.[20]
In Trinidad, tungiasis reaches a peak infestation rate of 54% among males aged 25-35 years. Among females, the peak occurs in those aged 55 years and older.[20] In a village in northeastern Brazil, bimodal prevalence peaks were noted in children aged 5-9 years and in adults older than age 60 years.[17]
Prognosis
The prognosis in tungiasis is excellent if proper sterile methods are followed for the extraction of fleas. Uncomplicated infestation results in pain, swelling, tenderness, and some limitation in mobility (although sometimes lesions are pruritic or even asymptomatic). As previously mentioned, however, complications can occur, including secondary infections, such as bacteremia or septicemia, lymphangitis, tetanus, and gas gangrene. (These infections may follow attempts to extract the flea.) Autoamputation of digits or other extensive soft tissue debridement is also a possibility. Death from tetanus associated with tungiasis has been reported.[4]
Among a native population in Brazil, the most common causes of bacterial superinfection included Staphylococcus aureus and various Enterobacteriaceae; anaerobic streptococci and Clostridium species were also found.[21]
To prevent superinfection, sand fleas should be surgically extracted immediately after penetration and the crater should be treated with topical antibiotic.[21]
Veraldi S, Valsecchi M. Imported tungiasis: a report of 19 cases and review of the literature. Int J Dermatol. Oct 2007;46(10):1061-6. [Medline].
Gibbs SS. The diagnosis and treatment of tungiasis. Br J Dermatol. Sep 2008;159(4):981. [Medline].
Feldmeier H, Eisele M, Van Marck E, Mehlhorn H, Ribeiro R, Heukelbach J. Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil: IV. Clinical and histopathology. Parasitol Res. Oct 2004;94(4):275-282. [Medline].
Pilger D, Schwalfenberg S, Heukelbach J, Witt L, Mehlhorn H, Mencke N, et al. Investigations on the biology, epidemiology, pathology, and control of Tunga penetrans in Brazil: VII. The importance of animal reservoirs for human infestation. Parasitol Res. Apr 2008;102(5):875-80. [Medline].
Caumes E, Carrière J, Guermonprez G, Bricaire F, Danis M, Gentilini M. Dermatoses associated with travel to tropical countries: a prospective study of the diagnosis and management of 269 patients presenting to a tropical disease unit. Clin Infect Dis. Mar 1995;20(3):542-8. [Medline].
Clyti E, Couppie P, Deligny C, Jouary T, Sainte-Marie D, Pradinaud R. [Effectiveness of 20% salicylated vaseline in the treatment of profuse tungiasis. Report of 8 cases in French Guiana]. Bull Soc Pathol Exot. Jan 2003;96(5):412-4. [Medline].
Fein H, Naseem S, Witte DP, Garcia VF, Lucky A, Staat MA. Tungiasis in North America: a report of 2 cases in internationally adopted children. J Pediatr. Nov 2001;139(5):744-6. [Medline].
Escamilla-Martinez E, Gómez-Martín B, Sánchez-Rodríguez R, Martínez-Nova A, Martínez-Granada LJ, Altube-Arabiurrutia E. Tungiasis--traveler's ectoparasitosis of the foot: a case report. Foot Ankle Int. Mar 2008;29(3):354-7. [Medline].
Bourée P, Ossé L, Rabenandrasana F. [Tungiasis, an uncommon ectoparisitic disease]. Rev Prat. Feb 20 2009;59(2):163-5. [Medline].
Sanusi ID, Brown EB, Shepard TG, Grafton WD. Tungiasis: report of one case and review of the 14 reported cases in the United States. J Am Acad Dermatol. May 1989;20(5 Pt 2):941-4. [Medline].
Mashek H, Licznerski B, Pincus S. Tungiasis in New York. Int J Dermatol. Apr 1997;36(4):276-8. [Medline].
Poppiti R Jr, Kambour M, Robinson MJ, Rywlin AM. Tunga penetrans in south Florida. South Med J. Dec 1983;76(12):1558-60. [Medline].
Brothers W, Heckmann R. Tungiasis (Tunga penetrans) in Utah. J Parasitol. Oct 1979;65(5):782. [Medline].
Hager J, Jacobs A, Orengo IF, Rosen T. Tungiasis in the United States: a travel souvenir. Dermatol Online J. Dec 15 2008;14(12):3. [Medline].
GIDEON Infectious Diseases - Tungiasis. Available at http://web.gideononline.com/web/epidemiology/index.php?disease=12490&country=G242&view=Distribution. Accessed 5/5/2011.
Ugbomoiko US, Ofoezie IE, Heukelbach J. Tungiasis: high prevalence, parasite load, and morbidity in a rural community in Lagos State, Nigeria. Int J Dermatol. May 2007;46(5):475-81. [Medline].
Muehlen M, Heukelbach J, Wilcke T, Winter B, Mehlhorn H, Feldmeier H. Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil. II. Prevalence, parasite load and topographic distribution of lesions in the population of a traditional fishing village. Parasitol Res. Aug 2003;90(6):449-55. [Medline].
Damazio OR, Silva MV. Tungiasis in schoolchildren in Criciúma, Santa Catarina State, South Brazil. Rev Inst Med Trop Sao Paulo. Mar-Apr 2009;51(2):103-8. [Medline].
Joseph JK, Bazile J, Mutter J, Shin S, Ruddle A, Ivers L, et al. Tungiasis in rural Haiti: a community-based response. Trans R Soc Trop Med Hyg. Oct 2006;100(10):970-4. [Medline].
Chadee DD. Tungiasis among five communities in south-western Trinidad, West Indies. Ann Trop Med Parasitol. Jan 1998;92(1):107-13. [Medline].
Feldmeier H, Heukelbach J, Eisele M, Sousa AQ, Barbosa LM, Carvalho CB. Bacterial superinfection in human tungiasis. Trop Med Int Health. Jul 2002;7(7):559-64. [Medline].
Rathe M, Rafn A, Poulsen T, Mohey R. [Tungiasis case after a trip to Kenya]. Ugeskr Laeger. Mar 2 2009;171(10):818. [Medline].
Heukelbach J, Wilcke T, Eisele M, Feldmeier H. Ectopic localization of tungiasis. Am J Trop Med Hyg. Aug 2002;67(2):214-6. [Medline].
Veraldi S, Schianchi R, Cremonesi R. Bullous tungiasis. Int J Dermatol. Dec 2005;44(12):1067-9. [Medline].
Di Stefani A, Rudolph CM, Hofmann-Wellenhof R, Müllegger RR. An additional dermoscopic feature of tungiasis. Arch Dermatol. Aug 2005;141(8):1045-6. [Medline].
Cabrera R, Daza F. Dermoscopy in the diagnosis of tungiasis. Br J Dermatol. May 2009;160(5):1136-7. [Medline].
Bauer J, Forschner A, Garbe C, Röcken M. Dermoscopy of tungiasis. Arch Dermatol. Jun 2004;140(6):761-3. [Medline].
Smith MD, Procop GW. Typical histologic features of Tunga penetrans in skin biopsies. Arch Pathol Lab Med. Jun 2002;126(6):714-6. [Medline].
Eisele M, Heukelbach J, Van Marck E, Mehlhorn H, Meckes O, Franck S, et al. Investigations on the biology, epidemiology, pathology and control of Tunga penetrans in Brazil: I. Natural history of tungiasis in man. Parasitol Res. Jun 2003;90(2):87-99. [Medline].
Heukelbach J, Eisele M, Jackson A, Feldmeier H. Topical treatment of tungiasis: a randomized, controlled trial. Ann Trop Med Parasitol. Oct 2003;97(7):743-9. [Medline].
Heukelbach J, Franck S, Feldmeier H. Therapy of tungiasis: a double-blinded randomized controlled trial with oral ivermectin. Mem Inst Oswaldo Cruz. Dec 2004;99(8):873-6. [Medline].
Feldmeier H, Kehr JD, Heukelbach J. A plant-based repellent protects against Tunga penetrans infestation and sand flea disease. Acta Trop. Oct 2006;99(2-3):126-36. [Medline].
Buckendahl J, Heukelbach J, Ariza L, Kehr JD, Seidenschwang M, Feldmeier H. Control of tungiasis through intermittent application of a plant-based repellent: an intervention study in a resource-poor community in Brazil. PLoS Negl Trop Dis. Nov 9 2010;4(11):e879. [Medline]. [Full Text].
Ade-Serrano MA, Olomolehin OG, Adewunmi A. Treatment of human tungiasis with niridazole (Ambilhar) a double-blind placebo-controlled trial. Ann Trop Med Parasitol. Feb 1982;76(1):89-92. [Medline].
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