Cordylobia anthropophaga

Cordylobia anthropophaga
Adult
Larva
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Diptera
Family:	Calliphoridae
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

Its specific epithet anthropophaga derives from the Greek word anthropophagos, "human eater".

The mode of infection by the Cayor Worm. Doctors Rodhain and Bequaert conclude, from their observations in the

Natal. In the region of Lower 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 humans. 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.

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 1872. In 1903, Grünberg placed the tumbu fly in a new genus, Cordylobia.^[3]

Life cycle

Female tumbu flies deposit around 300 eggs in sandy soil, often contaminated with feces. The hatched larvae can remain viable in the soil for 9–15 days, when they need to find a host to continue developing.^[4] If a larva finds a host, it penetrates the skin and takes 8–12 days developing through three larval stages before it reaches the prepupal stage. It then leaves the host, drops to the ground, buries itself, and pupates. 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 results 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

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 and infection.[7] If the larvae hatch in soil, any disturbance of the soil causes them to wriggle to the surface to penetrate the skin of the host.^[5]

Reservoir and vector

A natural 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, relative to myiasis in humans, animal hosts are 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; the larvae cannot develop when they enter the tissue of a fowl.^[3]

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

A

When C. anthropophaga causes cutaneous myiasis, the larvae more often than not can be removed without any incision. Covering the punctum (the breathing hole) with petroleum jelly or similar substances cuts off the air supply and forces the maggot to the surface, where it is easy to capture with forceps. If this does not work, local anesthetic can be administered and an incision made to widen the punctum and remove the maggot.^[5] Another treatment discussed in the March 2014 Journal of the American Medical Association is to inject a combination of anaesthetic and epinephrine into the insect's chamber. Less drastically, because larvae of C. anthropophaga have smaller hooked bristles on the cuticle than those of Dermatobia hominis, it often is practical just to push on each side of the hole to squeeze the maggot out, especially after first enlarging the punctum. It is important not to burst the larva to prevent the risk of granulomatous or serious inflammatory reaction.^[8]

Patients should be monitored for additional and subsequent lesions, as development does not occur in unison and some larvae may take longer to reach the prepupal stage. Antiseptics or antibiotics may be useful to prevent bacterial infection after removal of the larvae, but in practice are not often necessary; the secretions of the larva tend to discourage bacterial growth. As a rule, the wound may be expected to heal readily.^[9]

Epidemiology

The tumbu fly is endemic to the tropical regions of Africa, south of the Sahara. 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.^[10] The eggs hatch in one to three days and the larvae (which 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 kills the eggs/larvae.^[11][12]

References