Answer to Case 603

Answer to Case of the Week 603:Borreliasp. spirochetes. The history is most consistent with a relapsing feverBorreliasp., and subsequent PCR showed this to beBorrelia hermsii. As Florida Fan mentioned, this case is a great reminder that when we examine a Giemsa-stained blood film, we may find things other than parasites. In addition to spirochetal bacteria such as in this case, we can find intracellular clusters (morulae) ofAnaplasma phagocytophilumandEhrlichicaspp. bacteria, and intracellular years (e.g.Histoplasma capsulatum, Talaromyces marneffei).Leishmaniaspp. amastigotes can also rarely be seen within phagocytic cells. I ' ve shownBorreliaspirochetes on this blog before (seeCase of the Week 502), but never on a thick film, so I thought this would be a nice case to include here.Note that the spirochetes are uniformly slender with broad undulations. This is different than the microgametes of an exflaggelatedPlasmodiumsp. microgametocyte which I previously showed onParasite Case of the Week 595. In that case, I created a composite image of ' squiggly things ' seen on a blood smear which may be helpful in identifying and differentiating them:Some readers asked if theBorreliaspecies that cause Lyme disease could also be seen on blood film. The answer to this isNO - with one small caveat. The main cause of Lyme in the United States and Canada isBorrelia burgdorferi,whereas in Europe, you can also seeB. gariniiandB. afzelii.These organisms have extremely low levels o...
Source: Creepy Dreadful Wonderful Parasites - Category: Parasitology Tags: borrelia Source Type: blogs