Monday, February 19, 2018

Case of the Week 482

This week's case was donated by Dr. Paul Green. The following worm was removed from the eye of a Nigerian man, and was noted to still be moving after removal:
 Although it was damaged during removal, the key diagnostic features are still visible.

Anterior end:

mid-body with disrupted area:

Closer look at the internal organs:

Posterior end:
Identification? What additional specimen could confirm your diagnosis?


Ali said...

Loa loa adult female worm.

William Sears said...

Adult Loa Loa, female. size, Buccal canal is straight, esophagus is muscular, and the photograph of posterior end showing anus all consistent with loa loa. Eggs shown will eventually produce microfiliariae which could be used for additional diagnostic information. Would expect them to be sheathed, with nuclei extending all the way to tail. The blood should be collected during daytime since there is a diurnal release (that kind of synchronization is amazing but I guess coral polyps do it so why not nematodes...)

Anonymous said...

Loa loa, and gorgeous pictures!
bw in vt

Anonymous said...

What a nice case, we do not get to see the adult worm in the USA except the microfilaria form and even these only in the proficiencies. Thank you for such an educational opportunity.
Florida Fan

Atiya kausar said...

Loa loa female adult with eggs.... well explained by William Sears.. Additional test definitely will be a blood smear prepared day time 10 am to 2 pm...

Idzi P. said...

Adult female of Loa loa.
Can be confirmed by finding the microfilariae in the patient's blood.
KNOTT concentration yields good sensitivity for this.
Very nice pictures indeed!
I never saw the adult still moving after extraction!
Very cool video material!!!

Anonymous said...

Clearly everyone recognizes Loa Loa, but I initially - as non-expert- thought of Onchocerca volvulus first. What is the clear differentiating factor to distinguish these two?

ParasiteGal said...

Good question Anon! Onchocerca volvulus is only seen in its microfilariae form in the eye, whereas Loa loa is seen in its adult form. The microfilariae of O. volvulus are microscopic and therefore would never been seen with the naked eye like the worm in this case was. Thanks for writing.