2 - Why trichomonads have been overlooked until now ?
In medical practice, two groups of observers can detect trichomonads: parasitologists and cytopathologists.
Parasitologists recognize trichomonads that present in flagellated form. They spot the parasite by the motion of their flagella.
Cytopathologists recognize trichomonads in Pap smears, not by their flagella – which are not stained – but by their calibrated shape
and their faintly stained elliptic nucleus.
Thus, amoeboid trichomonads on slides colored by MGG do not harbor a familiar appearance both for parasitologists and for cytopathologists.
Another reason of the occultation of trichomonads refers to the observer rather than to the misleading morphology of trichomonad.
Away from the genito-urinary tract, and facing a trichomonad in BALF that has developed into an amoeboid form, nobody is ready to
consider trichomonad in this location.
Lastly, the traditional taxonomic position of the genus Trichomonas as "flagellated" has led to the erroneous conception that trichomonads always bear flagella.
