Sunday, October 23, 2016

Case of the Week 419

This week's case was generously donated by Dr. Steve Jenkins. The object below was seen in a wet prep of semen. Identification?

Tuesday, October 18, 2016

Case of the Week 418

This week's case is from a young man from Africa with fevers. No further travel history is available. The following are images from peripheral blood preparations. Identification?

Unstained blood, Knott's concentration, 10x objective (100x total magnification):

Unstained blood, 40x (400x total):

Thick film, Giemsa, 50x (500x total):

Thick film, Giemsa, 100x (1000x total):

Sunday, October 16, 2016

Answer to Case 418

Answer: Loa loa

Florida Fan nicely describes the important features of this case:
"The microfilariae are sheathed which narrows the choice to only three: Wuchereria bancrofti, Loa loa and Brugia malayi/Brugia timori. The sheath did not stain pink, and the patient did not come from Southeast Asia or Polynesia, thus eliminating B. malayi" (although the pink sheath is not always seen with B. malayi). "The column of nuclei extends all the way to the end of the tail and this differentiates these microfilariae from those of W. bancrofti. We have one last choice: Loa loa." 

Blaine will remind us that the sheath is not always seen, and therefore the size of the microfilariae should also be taken into consideration. The unsheathed microfilariae of Mansonella spp. are significantly narrower than the others, which is a helpful feature in eliminating this filarial worm from the differential.

Here are some of the key diagnostic findings seen in the images in this case:

Tuesday, October 11, 2016

Case of the Week 417

This week's case is a cool little finding from my lab, with videos by Emily F. Specimen type is urine (filtered through a Nuclepore (R) membrane), and the object shown measures approximately 150 micrometers in length.


Monday, October 10, 2016

Answer to Case 417

Answer: Schistosoma haematobium egg containing a live miracidium.

The video in this case nicely shows the movement of the miracidium as it beats its circumferential cilia and retracts its apical papilla. Normally internal "flame" cells (protonephridium) can also been seen moving, but these cannot be appreciated in this video.

Wednesday, October 5, 2016

Case of the Week 416

This week's case was generously donated by Mr. Boren Huot, and is in honor of George from Memorial Sloan Kettering Cancer Center, who just showed me a very striking example of a similar case.

The patient is a young woman with watery diarrhea. The following organisms were seen in stool concentrate. Identification?

Tuesday, October 4, 2016

Answer to Case 416

Answer: Strongyloides stercoralis adult female worms containing eggs and rhabditiform larvae. A possible filariform larva is also seen.

Adults worms are almost never seen in the stool of patients with strongyloidiasis, but when present, indicate a likely heavy infection. This case is remarkable because eggs and larvae are seen within the adult worms, illustrating how quickly the eggs hatch in the normal life cycle of this worm. The adult female usually lays the eggs directly in the intestinal mucosa where they quickly hatch to release rhabditiform larvae. This is why larvae, and not eggs, are found in the stool of patients with S. stercoralis infection.

Thanks again to Boren for donating this fascinating case.