Geographic region: West and Central Africa
Other microfilaria in geographic region:
(1) Onchocerca volvulus (large cephalic space)
(2) Mansonella perstans (straight tail with prominent terminal nucleus)
(3) Mansonella streptocerca (unsheathed, tapered hook tail with nuclei extending to end of the tail)
(4) Wuchereria bancrofti (sheathed)
Vector: Chrysops (red or tabanid fly)
Clinical findings:
(1) Calabar swellings (migratory angioedematous swellings that occur anywhere on body but typically on the face and distal extremities)
(2) migration through the subconjunctiva ("eye worm")
(3) urticaria and pruritis
(4) nephropathy with hematuria or proteinuria
(5) eosinophilia and elevated serum IgE
Uncommon adverse effects:
(1) entrapment neuropathy
(2) arthritis
(3) lymphadenitis
(4) hydrocele
(5) pleural effusion
(6) ocular involvement (macular retinopathy, posterior uveitis, retinal artery occlusion)
(7) eosinophilic myocarditis with endomyocardial fibrosis
(8) encephalitis, which can be fatal
Diagnosis:
(1) extraction of an adult worm from the conjunctiva or subcutaneous tissue
(2) The microfilaria may be seen in the peripheral blood smear with a diurnal periodicity. These are sheathed with a straight tail and a column of nuclei in the tail that do not extend to tip.
(3) serology if positive with an appropriate exposure history
(4) PCR
