Plasmodium spp. II

Question 1

Plasmodium spp. - Infected Red Cell (size):

-P. vivax/P. ovale

Answer 1

• Enlarged (reticulocyte)

- Fimbriated (+/-; P ovale)

Question 2

Plasmodium spp. - Infected Red Cell (size):

-P. malariae

Answer 2

Small to normal size

Question 3

Plasmodium spp. - Infected Red Cell (size):

-P. falciparum

Answer 3

ALL sizes

Question 4

Plasmodium spp. - Ring Form Trophozoite:

-P. vivax/P. ovale

Answer 4

Large
(>1/3 size of RBC)

*multiple infection not common

Question 5

Plasmodium spp. - Ring Form Trophozoite:

-P. malariae (3)

Answer 5

• Thick
• Small (<1/3 RBC)
• “Birds eye” forms*

*chromatin dot appears to be detached in center of ring”

Question 6

Plasmodium spp. - Ring Form Trophozoite:

-P. falciparum (5)

Answer 6

• Delicate
• Small (<1/3 RBC)
• 2 chromatin dots (+/-; “Headphones”)
• Applique forms

*Multiple infected RBCs common

Question 7

Plasmodium spp. - Mature Trophozoite:

• P. vivax
• P. ovale

Answer 7

P. vivax:
-Large, Amoeboid form that fills RBCs

P. ovale:

• Comet form
• More compact than P. vivax

Question 8

Plasmodium spp. - Mature Trophozoite:

-P. malaraie (3)

Answer 8

• “Band”/”Basket” forms
• Do NOT fill RBC
• Prominent Hematin pigment

Question 9

Plasmodium spp. - Mature Trophozoite:

-P. falciparum

Answer 9

RARE in peripheral blood

Question 10

Plasmodium spp. - Schizont (# of merozoites):

• P. vivax
• P. ovale

Answer 10

P. vivax:
>12 merozoites (12-24)

P. ovale:
>6 merozoites (6-14)

Question 11

Plasmodium spp. - Schizont (# of merozoites):

-P. malariae

Answer 11

6-12 merozoites

-Surround clump of hematin pigment (“Rosette” form)

Question 12

Plasmodium spp. - Schizont (# of merozoites):

-P. falciparum

Answer 12

RARE in peripheral blood

Question 13

Plasmodium spp. - Gametocytes:

-P. vivax/P. ovale (2)

Answer 13

• Large

- Oval

Question 14

Plasmodium spp. - Gametocytes:

-P. malariae

Answer 14

• Oval

- Fills RBC

Question 15

Plasmodium spp. - Gametocytes:

-P. falciparum

Answer 15

Banana-shape

-Distorts RBC

Question 16

Plasmodium spp. - Inclusions:

-P. vivax/P. ovale

Answer 16

Schuffner dots

-“Stippling”

Question 17

Plasmodium spp. - Inclusions:

-P. malariae

Answer 17

NONE

Question 18

Plasmodium spp. - Inclusions (gametocytes):

-P. falciparum

Answer 18

Maurer clefts

-Round to Comma-shaped red cytoplasmic dots

Question 19

P. falciparum:
-Forms seen in peripheral blood

*what about the intermediate forms?

Answer 19

• RIng forms
• Gametozytes

*Erythrocytes with intermediate forms are sequestered in the capillaries of the liver, brain, heart and kidneys

Question 20

P. ovale infected erythrocyte characteristics. (2)

Answer 20

• Oval (hence ovale)

- Fimbriated (+/-)

Question 21

Mixed plasmodium spp. infections:

• Incidence
• Species

Answer 21

5%

-P. falciparum/P. vivax

Question 22

Degree of parasitemia (% infected RBCs) is most important with what species?

• % considered severe
• Treatment effect

Answer 22

P. falciparum

• > 2% is severe
• Transient increase in parasitemia after treatment, followed by progressive diminution