Cordylobia anthropophaga

Cordylobia anthropophaga
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Calliphoridae
Tribe:	Calliphorini
Genus:	Cordylobia
Species:	C. anthropophaga
Binomial name
Cordylobia anthropophaga (Blanchard, 1872)
Synonyms
Ochromyia anthropophaga Blanchard, 1872

Cordylobia anthropophaga, the mango fly, tumbu fly, tumba fly, putzi fly or skin maggot fly is a species of blow-fly common in East and Central Africa. It is a parasite of large mammals (including humans) during its larval stage .^[1]C. anthropophaga has been endemic in the subtropics of Africa for more than 135 years and is a common cause of myiasis in humans in the region.^[2]

Its specific epithet anthropophaga derives from the Greek word anthropophagus, "eater of men".

"The Mode of infection by the Cayor Worm. Doctors Rodhain and Bequaert conclude, from their observations in the Congo Free State, that Cordylobia anthropophaga (Grunberg) lays its eggs on the ground. The larvae, known generally as Cayor worms, crawl over the soil until they come in contact with man or a mammal, penetrate the skin and lie in the subcutaneous tissue, causing the formation of tumors. On reaching full growth, the larvae leave the host, fall to the ground, bury themselves and there pupate. This fly is said to be the most common cause of human or animal myiasis in tropical Africa, from Senegal to Natal. In the region of Bas-Katanga where these investigations were made, dogs appeared to be the principal hosts, although Cordylobia larvae were found also in guinea-pigs, a monkey and two white men. The larvae are always localized on those parts of the hosts which come in immediate contact with the soil." (Ann. Soc. Entom. de Belgique, Iv, pp. 192–197, 1911) summary translation in Entomological News. 1911 Vol. xxii:467.

History of Discovery

The larvae of the tumbu fly, Cordylobia anthropophaga, were first described in Senegal in 1862, and Blanchard first described the adult and gave it its name in 1893. In 1903, Grunbert placed the tumbu fly in a new genus, Cordylobia.^[3]

Life cycle

Female tumbu flies deposit 100-300 eggs in sandy soil often contaminated with animal feces. The hatched larvae can remain viable in the soil for 9–15 days until they need to find a host for development.^[4] If a larva finds a host, it will penetrate the skin and take 8–12 days developing through three larval stages before it reaches the prepupal stage. It will then leave the host, drop to the ground, bury itself, and pupate. It then becomes an adult fly able to reproduce and begin the cycle all over again.^[5]

Clinical Presentation in Humans

Successful penetrations in humans will result in furuncular (boil-like) myiasis, typically on the backs of arms or about the waist, lower back, or buttocks.^[6]

C. anthropophaga rarely causes severe problems, and mainly causes cutaneous myiasis. Geary et al. describe the presentation of cutaneous myiasis caused by the tumbu fly: "At the site of penetration, a red papule forms and gradually enlarges. At first the host may experience only intermittent, slight itching, but pain develops and increases in frequency and intensity as the lesions develop into a furuncle. The furuncle's aperture opens, permitting fluids containing blood and waste products of the maggot to drain."^[5]

Transmission

Female tumbu flies lay their eggs in soil contaminated with feces or urine or on damp clothing or bed linens. Damp clothing hanging to dry makes for a perfect spot. The larvae hatch in 2–3 days and attach to unbroken skin and penetrate the skin, producing swelling.^[7] If the larvae hatch in soil, any disturbance of the soil causes them to wiggle to the surface to penetrate the skin of the host.^[5]

Reservoir and Vector

A reservoir is defined as an organism that can harbor a pathogen indefinitely with no ill effects. Although C. anthropophaga larvae can cause ill effects for animal hosts, because we are talking about myiasis in humans, we will consider any animal hosts as reservoirs.

Many animals are hosts of C. anthropophaga. The dog is the most common domestic host and several species of wild rats are the preferred field hosts. Domestic fowl are dead-end hosts, meaning that the larvae cannot develop when they enter the tissue of fowl.^[3]

Humans are in fact accidental hosts, which means that tumbu fly larvae do not usually infect humans and we are not necessary for the transmission cycle of the fly.^[2]

A vector is an organism that carries the parasites (the larvae) from one host to another. The tumbu fly itself is the vector in a loose sense, because the female deposits the eggs in soil or on damp cloth, where the larvae can hatch and attach to human or animal skin.^[7]

Diagnostics

Cutaneous myiasis caused by the tumbu fly should be suspected when a patient who has just spent time in Africa presents with ulcers or boil-like sores. A definitive diagnose can only be made when the larvae are found. They should be removed and allowed to develop into adult flies for identification purposes.^[7]

Treatment

In cases of cutaneous myiasis, the larvae are most often removed without an incision. Applying Vaseline to the skin blocks the breathing hole and cuts off the larva’s air supply. This will force the maggot to the surface of the skin as it searches for air. The larvae can then easily be extracted from the skin. If this does not work, local anesthetic can be administered and an incision is made to extract the maggot.^[5]

Patients should be monitored for additional and subsequent lesions as development does not occur all at once and some larvae may take longer to reach the prepupal stage. To prevent bacterial infection after removal of the larvae, antibiotics can be administered.^[8]

Epidemiology

C. anthropophaga is the most common causes of myiasis in Africa (WHO).

The tumbu fly is endemic to the tropical regions of Africa, south of the Sahara desert. Myiasis caused by C. anthropophaga is the most common cause of myiasis in Africa but can be seen worldwide because of air travel, as human movements carry infestation outside endemic areas.^[7]

Public Health and Prevention Strategies

The fly commonly infects humans by laying its eggs on wet clothes, left out to dry.^[9] The eggs hatches in one to three days and the larvae (who can survive without a host for up to 15 days) then burrow into the skin when the clothes are worn.^[1] A prevention method is to iron all clothes (including underwear) which will kill the eggs/larvae.^[10][11]

See also

• Dermatobia hominis

References

1. ^ ^{a b} "African tumbu fly". Merck Veterinary Manual. http://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/71725.htm. Retrieved 2007-08-18. 
2. ^ ^{a b} Adisa, Charles Adeyinka; Augustus Mbanaso (February 2004). "Furuncular myiasis of the breast caused by the larvae of the Tumbu fly (Cordylobia anthropophaga)". BMC Surgery 4 (1): 5. doi:10.1186/1471-2482-4-5. PMC 394335. PMID 15113429. http://www.biomedcentral.com/1471-2482/4/5. Retrieved 2009-03-17. 
3. ^ ^{a b} Rice, Paul L.; Neva Gleason (January 1972). "Two cases of myiasis in the United States by the African tumbu fly, Cordylobia anthropophaga (Diptera, Calliphoridae)". American Journal of Tropical Medicine and Hygiene 21 (2): 62–5. PMID 5007189. http://www.ajtmh.org/cgi/pmidlookup?view=long&pmid=5007189. Retrieved 2009-03-17. 
4. ^ Ockenhouse, Christian F.; Curt P. Samlaska, Paul M. Benson, Lyman W. Roberts, Arn Eliasson, Susan Malane and Mark D. Menich (February 1990). "Cutaneous myiasis caused by the African tumbu fly (Cordylobia anthropophaga)". Archives of Dermatology 126 (2): 199–202. doi:10.1001/archderm.126.2.199. PMID 2301958. http://archderm.ama-assn.org/cgi/content/abstract/126/2/199. Retrieved 2009-03-17. 
5. ^ ^{a b c d} Geary, Merilyn J.; Bernard J. Hudson, Richard C. Russell and Andrew Hardy (1999). "Exotic myiasis with Lund's fly (Cordylobia rodhaini)". Medical Journal of Australia 171 (11-12): 654–5. PMID 10721359. http://www.mja.com.au/public/issues/171_11_061299/geary/geary.html. Retrieved 2009-03-17. 
6. ^ Zijlma, Anouk. "About the putzi fly". About.com. http://goafrica.about.com/od/healthandsafety/qt/putzifly.htm. Retrieved 2007-08-18. 
7. ^ ^{a b c d} John, David; William Petri (2006). Markell and Voge's Medical Parasitology (9th ed.). St. Louis, Missouri: Elsevier. pp. 329. ISBN 0-7216-4793-6. OCLC 62475633. http://books.google.com/?id=-QSZD783cdsC. 
8. ^ Sherman RA, Hall MJ, Thomas S (2000). "Medicinal maggots: an ancient remedy for some contemporary afflictions". Annual Review of Entomology 45 (1): 55–81. doi:10.1146/annurev.ento.45.1.55. PMID 10761570. 
9. ^ http://www.hpa.org.uk/cdr/archives/1992/cdr1092.pdf
10. ^ Adisa CA, Mbanaso A (2004). "'Furuncular myiasis of the breast caused by the larvae of the Tumbu fly (Cordylobia anthropophaga)'". BMC Surgery 4: 5. doi:10.1186/1471-2482-4-5. PMC 394335. PMID 15113429. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=394335. 
11. ^ James AS, Stevenson J (March 1992). "Cutaneous myiasis due to Tumbu fly". Archives of Emergency Medicine 9 (1): 58–61. PMC 1285829. PMID 1567531. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1285829.