Tumbu fly ( Cordylobia anthropophaga )

• myiasis is an infestation of human tissue by the larvae of certain flies. There are many forms of myiasis, including localized furuncular myiasis, creeping dermal myiasis and wound and body cavity myiasis.
  • Cordylobia anthropophaga (the Tumbu fly) and Dermatobia hominis (the human botfly) are the most common causes of myiasis in Africa and tropical America respectively
  • the female fly deposits her eggs on dry sand polluted with the excrement of animals or on human clothing - the larva is activated by the warm body of the host, hatches and invades the skin.
  • as the larva matures, it induces a furuncular swelling. It eventually exits the skin and falls to the ground to pupate. The adult fly then emerges and the life cycle resumes
  • in humans, the skin lesion starts as a red papule that gradually enlarges and develops into a furuncle (boil) that moves. In the centre of the lesion an opening forms, through which the larva breaths and discharges its serosanguinous feces. The lesion is associated with increasing pain until the larva exits the skin. The disease is usually uncomplicated and self-limiting.
• treatment:
  • removal of the larva followed by twice daily application of an antibacterial ointment (3). In this method the extraction was done by injecting 2% xylocaine over the base of the nodule. Care was exercised in not damaging the larva while extracting
  • it has also been suggested that treatment/asphyxiation of the larvae could be achieved via covering the opening of the skin lesion with an occlusive dressing (1) - the larva would then need to be removed

Reference:

1. Pulse (2003), 63 (45), 61.
2. J Travel Med. 2003 Sep-Oct;10(5):293-5.
3. J Coll Physicians Surg Pak. 2003 Apr;13(4):195-7.