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[Brugia malayi] [Brugia timori] [Dirofilaria spp.] [Loa loa] [Mansonella ozzardi] [Mansonella perstans] [Mansonella streptocerca] [Onchocerca volvulus] [Wuchereria bancrofti]

Microfilariae of Onchocerca volvulus are unsheathed and measure 300-315 µm in length.  The tail tapers to a point and is often sharply bent.  The nuclei do not extend to the tip of the tail.  Microfilariae typically reside in skin but may be found in blood or urine during heavy infections, or invade the eye and cause a condition known as river blindness.

A	B

A:  Microfilariae of O. volvulus from a skin nodule of a patient from Zambia, stained with hematoxylin and eosin (H&E).  Image taken at 1000x oil magnification.
B:  Microfilariae of O. volvulus within the uterus of an adult female.  The specimen was taken from the same patient as in Figure A.  Image taken at 500x magnification, oil.

C	D

C: Microfilariae of O. volvulus from a skin nodule of a patient from Zambia, stained with H&E.  Image taken at 1000x oil magnification.
D: Coiled microfilaria of O. volvulus, in a skin nodule from a patient from Zambia, stained with H&E.  Image taken at 1000x oil magnification.

E

E: Cross-section of an adult female O. volvulus, stained with H&E.  Note the presence of many microfilariae within the uterus.