A businessman recently returned from India with recurring fevers and malaise. The following were seen on peripheral blood films. Identification? (CLICK ON IMAGES TO ENLARGE)
Infected RBCs are larger than non infected RBCs indicating a predilection for younger red cells: This eliminates P. malariae, P. falciparum as well as P. knowlesii. There is no fimbriation among the infected RBCs, plus the geographical area visited is not a hot bed for P. ovale. The identification based on morphology is consistent with P. vivax.
1. It has extra-cellular forms. 2. Size variability of ring-forms. 3. There is something like a "tennis racket-shaped" rings in the second photo. Babesia spp. tend to produce atypical forms, with multiple chromatin dots, 'double' rings, and chromatin 'tails' 4. There is not malarial pigment. 5. There are erythrocytes with several rings, but these are a bit thick to be P. falciparum. “Alea jacta est” Now we have to wait
From these slides, it is not a falciparum-vivax coinfection. Otherwise, we would see both enlarged RBCs with rings (vivax) and normal-sized RBCs with rings (falciparum).
Doubly-infected cells are quite uncommon outside of in vitro culture, so that last image is particularly cool. I would guess that multiply-infected cells are more common in P. vivax infections since there are not as many reticulocytes in circulation compared to erythrocytes.
I think this is P. vivax? Infected RBCs are enlarged, with Schuffner's dots and ameboid-shaped RBCs.
ReplyDeletePearlie.
P. vivax. What a beautiful doubly infected cell!
ReplyDeleteInfected RBCs are larger than non infected RBCs indicating a predilection for younger red cells: This eliminates P. malariae, P. falciparum as well as P. knowlesii. There is no fimbriation among the infected RBCs, plus the geographical area visited is not a hot bed for P. ovale.
ReplyDeleteThe identification based on morphology is consistent with P. vivax.
Florida fan
Vivax - The trophozoites look vivacious!
ReplyDeleteThis is unmistakably P. falciparum
ReplyDelete1.Ring forms
2. Multiple or super infection in one RBC
Plasmodium vivax
ReplyDeleteno way it is falciparum !
ReplyDeleteI am sticking with the crowd. Vivax. Stippling, ameoboid rings, larger than surrounding RBCs.
ReplyDeleteLee
This is vivax. Beautifully stained! Thanks for the images.
ReplyDeletePhilip Coyne
P.vivax based on the size of infected RBCs. I didn't know that one red cell can be infected by multiple rings..
ReplyDelete-from the Philippines
P.vivax .cant explain 2 rings in 1 rbc:-)
ReplyDeleteI think is Babesia. Because:
ReplyDelete1. It has extra-cellular forms.
2. Size variability of ring-forms.
3. There is something like a "tennis racket-shaped" rings in the second photo. Babesia spp. tend to produce atypical forms, with multiple chromatin dots, 'double' rings, and chromatin 'tails'
4. There is not malarial pigment.
5. There are erythrocytes with several rings, but these are a bit thick to be P. falciparum.
“Alea jacta est” Now we have to wait
it can also be a mixed infection of vivax-falciparum. Anyway, it is an intriguing case.
ReplyDeleteP. vivax.
ReplyDeleteFrom these slides, it is not a falciparum-vivax coinfection. Otherwise, we would see both enlarged RBCs with rings (vivax) and normal-sized RBCs with rings (falciparum).
Doubly-infected cells are quite uncommon outside of in vitro culture, so that last image is particularly cool. I would guess that multiply-infected cells are more common in P. vivax infections since there are not as many reticulocytes in circulation compared to erythrocytes.