Sunday, July 26, 2009

Answer to Case 79

Answer: Trypanosoma cruzi
It is important not to forget about these extracellular parasites when screening a blood smear for malaria parasites. This image shows the motile trypomastigotes of T. cruzi. Note that these organisms are approximately 2-3 RBCs in length, and contain a nucleus and kinetoplast (below, arrow). T. cruzi can be most readily distinguished from the trypomastigotes of Trypanosoma brucei by the size of the kinetoplast; the former is much larger and appears to bulge from the organism.

An interesting tidbit: Contrary to expected, the kinetoplast is at the posterior end of the organism, while the flagella is at the anterior end. The trypomastigotes move with their flagella at their front.

Thanks to the four folks who wrote in with the answer - all correct!

1 comment:

Salbrent said...

I agree but will add comment that the patient's travel history is an important of ID. Without it, you can only report Trypanosoma sp or perform IFA or EIA for T cruzi or culture to define it.
Treatment is benznidazole or nifurtimox from CDC Drug Serive under an Investigational New Drug protocol see
CDC Drug Service
1600 Clifton Road, MS/D09
Atlanta, GA 30333
Telephone (404) 639-3670 Fax (404) 639-3717

Great case, pics and information