Genera of flies involved with humans:
(1) Gasterophilus (horse bot fly)
(2) Hypoderma (cattle bot fly)
The larvae are unable to complete their life cycle in humans.
Risk factors for migratory myiasis:
(1) exposure to host animal (horse, cattle)
(2) presence of bot flies
(3) presence of other cases in the community
Clinical signs and symptoms:
(1) raised area of skin that migrates for weeks to months
(2) pruritus
Laboratory findings:
(1) hypereosinophilia
(2) presence of hypodermin C in the serum (for Hypoderma species)
(3) PCR
The larva can be seen by placing a drop of mineral oil over the advancing edege and looking at the site under a dissecting microscope or other magnifier. Alternatively the larvae can be visualized on ultrasonography.
Complications may include:
(1) cellulitis
(2) pustules
(3) migration to the lungs, brain or othe organs
