Diagnostic Findings [Last Modified: ]
Trichomoniasis
[Trichomonas vaginalis]
Causal Agent Life Cycle Geographic Distribution Clinical Features Laboratory Diagnosis Treatment

Microscopy

Trophozoites of Trichomonas vaginalis are pyriform and 7-30 µm long.  They have five flagella:  four anteriorly directed flagella and one posteriorly along the outer membrane of the undulating membrane.  The large nucleus is usually located at the wider, anterior end and contains many chromatin granules and a small karyosome.  The cytoplasm also contains many granules, but these are often not seen in Giemsa-stained specimens.

Trichomonas vaginalis, in vitro culture T. vaginalis trophozoite, iron hematoxylin stain
A B

A:  Two trophozoites of T. vaginalis obtained from in vitro culture, stained with Giemsa.
B:  Trophozoite of T. vaginalis stained with iron hematoxylin.

Trichomonas muris trophozoites, iodine stain
 C

C:  Trophozoites of T. muris stained with iodine.

Click here to view a video clip #1 of Trichomonas vaginalis (Adobe Flash)
Wet mount examination of vaginal secretions from a patient with Trichomonas vaginitis.  The organisms are motile, pear-shaped, 10 µm by 7 µm, with visible flagella.

Click here to view a video clip #2 of Trichomonas vaginalis (Adobe Flash)
Wet mount examination of a culture of Trichomonas vaginalis.

 

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