Monday, April 8, 2024

Case of the Week 744

 We are in the home stretch for the microfilariae! Can you believe that we have just a few more to go? (Unless I decide to repeat some 😉)  This week's case shows microfilariae that are approximately 200 micrometers long. The patient is a resident of Brazil and has moderate peripheral eosinophilia. He is otherwise asymptomatic. 

Carazzi stain (Knott's concentration):

Giemsa stain (thick blood film):


Lyne said...

Mansonella ozzardi microfilaria

Anonymous said...

This is a rather small microfilaria, its width is only about half the diameter of the surrounding neutrophils. The Carrazi stain did not show a sheath either. As such, we can definitely rule out all the sheathed and large microfilaria. We know that we are dealing with Mansonella species. The tail of this Mansonella is not curved , this allows us to eliminate Mansonella streptocerca (strepto = curved, cerca = tail). The tail is also not pointed, this rules out Mansonella ozzardi. We only have one left with a blunt tail: Mansonella perstans which persists.
Florida Fan

jebarnes said...

Agree with Florida Fan.

Anonymus said...

There`s the other one :)
The microfilariae of Mansonella perstans are reported to be longer (200×4–5 μm) than M. ozzardi (case 741), to have blunt rounded tails with nuclei extending to the tips.

Anonymous said...

Case 744?

ParasiteGal said...

Good catch, UZ. I clearly couldn't count yesterday ;)

Anonymous said...

Case study info?