Monday, June 15, 2020
Case of the Week 595
This week's case was generously donated by Dr. Marc Couturier and Blaine Mathison. The patient is a young adult male from the South Central United States. No travel history is available. Review of his peripheral blood film reviewed the following:
Identification? What are the structures seen in the last 2 images?
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25 comments:
This is a nice one!
I’ll refrain from giving it away already, but maybe a hint:
Blood (taken on an anticoagulant) was kept a while at room temperature before the smear was made!
This is clear from the last two pictures!
Exflagellated microgamete of malariae sp.
P. vivax -- released/free portions of the exflagellated microgametocyte caused by processing delay?
I agree with Plasmodium and leaning towards P vivax (vs ovale) with the larger, pale RBCs infected. Large number of schizonts in first image and the relatively deformability of the infected RBCs makes me lean to Pv. I also don't see any fimbriae. Not sure exactly what is in the last 2 slides. Seems too small to be a parasite (don't see any definite cytoplasm) and doesn't really look like Borrelia or other spirochetes on a blood smear. Assuming it is artifact or something altered in appearance due to way the film was made.
Surely a Plasmodium infection. Morphologically, for the gametocytes and slightly enlarged RBCs, I would say either vivax (but trophozoites are not really amoeboid, they seem a bit more compact) or ovale? In the last two it's very interesting to see some microgametes, exflagellation was induced because the sample was left at room temperature as specified above.
Plasmodium vivax
The infected red cells are enlarged, evidence of a predilection for reticulocytes. The numerous nucleus in the schizont, the "shy away" effect as well as the lack of fimbriation on the infected red cells as well as the geography tell us this is a case of P. vivax infection.
Yes, I will agree with Idzi that the exflagellation is evidence of a delay in the testing.
Florida Fan
P.vivax , and Trypanosoma
From the epidemiological point of view, the presence of plasmodium in a subject from the USA who has not traveled is intriguing and I want to ask the following questions. Has the subject been transfused? is it a recurrence of a Plamodium vivax contracted in childhood? is the geographical distribution changing from Latin America to the South of the United States?
The second parasite is too thin to be a trypanosome. In my opinion it is a blood microfilaria. This parasite resembles Mansonella perstans, but given the patient's geographic origin (America) and the lack of travel found it could also be M. ozzardi (which are neither pathogenic)
Plasmodium vivax
Plasmodium vivax + sporozoites
Agree with Plasmodium vivax trophozoites and schizonts. The organism that resemble a Treponema sp. is indeed a exflagellating male gametocyte.
Yess ibthink so
Trypanosoma may also be considered
Sembrano Tripanosomi, ma in realtà sono sporozoiti di P.vivax, rarissimi
Off topic: Dr. Pritt is quoted in an article about PCR tests for COVID-19
https://www.npr.org/sections/health-shots/2020/06/15/871186164/what-zebra-mussels-can-tell-us-about-errors-in-coronavirus-tests
Definitely not P. vivax or P. ovale because of no stipplings, and of course not P. falciparum. Maybe P. malariae, or if based on no travel history and geography, I would consider Babesia. Trypanosoma too?
Nowaday, it could a bit difficult to find Chloroquine in order to treat such malaria cases.
It’s a bit guessing, but based on the larger erythrocytes being infected and the lack of Shüffner granulation, I’d say P. vivax (I would expect intense Shüffner in ovale).
Last two pictures show exflagellates (formed by male gametocytes) due to a delay in processing (the parasite thinks it ended up in a mosquito, because of the drop in temperature). Cave: to be differentiated from recurrent fever borreliosis!
but not in US, where States have enough stockpiles
There is a question about the patient source of infection. Did the patient work at an airport, a port of entry where goods are imported? Did the patient happen to open an imported container? Or was the patient a recipient of a blood transfusion? To us this is the enigma.
As far as chloroquine, there should be no shortage of it, even when it's use is not efficace, not recommended, banned or lethal in some cases.
Florida Fan
Even from visiting a pub, one could get airport malaria! (Gratz, N. G.; Steffen, R.; Cocksedge, W. (2000). "Why aircraft disinsection?". Bulletin of the World Health Organization. 78 (8): 995–1004) So it could remain an enigma as for where this patient got his malaria...
Great points about airport malaria Idzi. I should also note that travel history is not available in this case (as is often the case when specimens are sent to a reference laboratory, sadly). This doesn't mean that the patient hasn't traveled - just that we weren't told anything!
loving the discussion and excellent take away teaching points....even if not directed at me specifically, thank you one and all, i truly appreciate this fantastic brain trust and learn something with every post! and yes, i was raising the exact same QA/QC points about PCRs and coronavirus in a seminar i gave on wednesday for WADEM... the World Association for Disaster and Emergency Medicine...
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