Answer to Case 484

Answer:Trypanosoma bruceiThis is most likelyT. brucei rhodesiensebased on:The patient ' s recent travel to Eastern Africa (Kenya),His participation in a game tracking excursion (classic history given that wild ungulates are the reservoir for this subspecies),His rapid onset of symptoms, andThe very high (!) parasitemiaBe sure to check out the video which show the characteristic ' auger ' like motility of the trypomastigotes (i.e. rotating along its long axis).Thanks to everyone who wrote in with the excellent comments. A lot of good points were raised by all. Ali Mokbel mentioned that we can ' t exclusively rule outT. b. gambiense,given that the patient is a frequent traveler and may have been to West Africa. Idzi also reminded us that the trypomastigotes ofT. bruceiare indistinguishable from those ofT. rangeli,a non-pathogenic New World trypanosome which can occasionally infect humans. Fortunately, we can tentatively rule out these other species/subspecies based on the very high parasitemia and patient ' s symptoms. If there was any question about the identification (e.g. based on the patient ' s travel history), sub-species determination using PCR could be performed.  Finally, LS reminded us of the importance of determining whether the patient had central nervous system involvement since that would change the therapy. If suspected, a lumbar puncture could be performed to look for trypomastigotes.For our students of parasitology, the following contains some ge...
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Source Type: blogs