Monday, April 1, 2024

Parasite Case of the Week 743

Welcome back for more microfilariae from Idzi Potters and the Institute of Tropical Medicine, Antwerp. The following microfilariae were seen in Giemsa-stained thick blood films from a man living on Alor Island, Indonesia. They measure approximately 305-315 micrometers in length. 

What is your identification? What is your primary differential?


nema said...

It looks like Brugia Malayi which is consistent with the geographical origin of the patient. My first differential diagnosis is Wucheria Bancrofti.

Anonymous said...

Oh yes, now we have it! This is a large microfilarium. The sheath is not very apparent yet visible. We are dealing with Loa loa, Wucheria bancrofti or the Brugia genus. First the column of nuclei is so compact that we can rule out Wucheria bancrofti, also the nuclei go to the end of the tail. Yet, the two terminal nuclei are distinctly separated from the nuclei column, this rule out any chance of being Loa loa. Now we have the Brugia genus left, but where is the pink sheath pertinent to Brugia malayi when stained with Giemsa stain? As such, we eliminate Brugia malayi. By the elimination process, we’re left with its cousin Brugia timori, the sheath of this one does not stain pink with Giemsa stain. Now let’s check the map of the lesser Sundae island, the Alor island is right North of Timor.
What an educational opportunity for us Parasitologists, thank you Dr. Pritt and Idzi this will help us be more confident facing CAP proficiencies.
Florida Fan

Anonymous said...

Based on size >200, we can rule out Mansonella species. I can see nuceli to the tip with gaps between the nuclei, and there is a visible long head empty space, making Brugia more likely.
Onchocerca volvulus comes in similar size too, but given that this is a blood film, the fact that the tail is nucleated, and that there is a sheath, Brugia spp. is more likely.
I see a sheath, but it's not bright pink, so I will go with Brugia timori.