Human Bot fly

Dermatobia hominis

Human Bot fly (Dermatobia hominis) The Human Bot fly (Dermatobia hominis) is one of hundreds of parasites that affect humans.The Human Bot fly, also known as the torsalo or berne, occurs in Central and South America (fortunately for us in Australia).

There have been occasional cases of tourists returning to Australia with a raised sore on their body (often on the arms or legs) that does not heal. This can be due to the presence of a 'maggot' or larva of the Bot fly developing just under the skin.

Bot flies don't lay their eggs directly on their hosts, which can be animals or humans. Instead an adult Bot fly captures a 'carrier' insect (for example a mosquito), on which it lays its eggs, and then releases it. The 'carrier' insect then lands and feeds on a warm blooded host (such as us), which stimulates hatching of the eggs, and the larvae drop onto the host and penetrate the unbroken skin.

If untreated the larvae can develop under the skin and go through a series of moults taking 1-2 months before emerging and dropping off the host to pupate in the soil. 

Once diagnosed, larvae can be removed easily through minor surgery.

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