Myiases

diseases of humans and animals that are caused by maggots. In a broader sense, the word “myiasis” refers to the presence of live maggots in the body of the host. Myiases are classified according to their localization; for example, there are cutaneous, cavitary, gastrointestinal, urogenital, and ophthalmic myiases.

The larvae of flies of the genus Gastrophilus in their first stage of development move through the surface layers of the skin causing dermatitis; these same larvae may parasitize the stomach of horses or, rarely, of humans. An infiltrate resembling a furuncle develops as a result of penetration of the skin by larvae of the genus Cordylobia. Severe myiases of the skin, gums, nose, ears, eyes, and, rarely, the genital organs are caused by the larvae of the screw-worm fly Wohlfahrtia magnified, which the insect discharges in flight. Larvae of the sheep botfly (Oestrus ovis), the Cantharis, and the horse botfly (Gastrophilus intestinalis) penetrate the nose and eyes. The larvae of the cheese fly (Piophila casei), the housefly (Musca domestica), flesh flies (Sarcophagidae), and other flies enter the stomach and intestines of humans with food products (salted fish, vegetables), causing stomach pains, nausea, vomiting, and diarrhea.

Treatment includes extracting the larvae from the passages they have made and removing them by means of forceps and irrigation from wounds, ulcers, and the conjunctiva. Larvae are removed from the stomach by irrigation and from the intestines by means of anthelminthics. Preventive measures include maintaining personal hygiene, cleanliness of dwellings, and good public sanitation, as well as protecting food products from flies.