Deck 47: Blood and Tissue Protozoa

Question 1

MATCHING
Match the size and shape of the parasitized RBCs as they appear in Giemsa-stained thin blood smears.Answers may be used more than once.
a.Normal shape and size
b.Normal shape;size may be normal or slightly smaller
c.1.5 to 2.0 times larger than normal;oval to normal
d.60% of cells are larger than normal and oval
P.malariae

Answer 1

B

Question 2

P.vivax is suspected in a patient who has been traveling for months in the tropics.Blood was collected in a lavender top tube;however,the slide was not prepared for examination until the next day because the specimen came in on the night shift.Once the slide was prepared and examined,Schüffner dots were not visible.Which one of the following statements explains this discrepancy?

A)Schüffner dots are not characteristic of P.vivax infections.
B)The blood film was most likely incorrectly prepared.
C)The blood should have been collected in a red top tube.
D)The blood remained in the tube too long,yielding false-negative results.

Answer 2

D
Blood collected using ethylenediaminetetraacetic acid (EDTA)anticoagulant is preferred;however,if the blood remains in the tube for any length of time before blood film preparation,then the Schüffner dots may not be visible after staining (e.g. ,P.vivax),and other morphologic changes in the parasites will be observed.

Question 3

Match the vector with the organism it infects.Answers may be used more than once.
a.Anopheles mosquito
b.Tsetse fly
c.Sandfly
d.Reduviid bug
T.brucei rhodesiense

Answer 3

B

Question 4

Humans contract Chagas disease when the reduviid bug defecates while taking a blood meal and the parasites in the feces are rubbed or scratched into the bite wound or onto mucosal surfaces.Which stage in the blood infects the host cells?

A)Amastigote
B)Epimastigote
C)Trypomastigote
D)Promastigote

Question 5

Delicate ring forms and crescent-shaped gametocytes are the only forms normally observed in the peripheral blood of which Plasmodium spp.?

A)P.vivax
B)P.malariae
C)P.falciparum
D)P.ovale

Question 6

Chagas disease is caused by:

A)Trypanosoma rangeli.
B)Trypanosoma cruzi.
C)Trypanosoma brucei rhodesiense.
D)Trypanosoma brucei gambiense.

Question 7

Cerebral malaria is considered to be the most serious complication and major cause of death with which species of Plasmodium spp.?

A)P.vivax
B)P.falciparum
C)P.ovale
D)P.malariae

Question 8

Resistance to chloroquine and mefloquine has been identified in which Plasmodium spp.?

A)P.ovale
B)P.vivax
C)P.falciparum
D)P.malariae

Question 9

Ring forms and a "Maltese cross" were observed in a blood smear.The vector that transmits this disease is a(n):

A)tick.
B)tsetse fly.
C)anopheles mosquito.
D)sandfly.

Question 10

In T.brucei rhodesiense trypanosomiasis infections,CNS invasion occurs early.The disease progresses rapidly,and death may occur before extensive CNS involvement.Inflammation of which organ is more common and severe with this disease form?

A)Kidney
B)Lungs
C)Liver
D)Heart

Question 11

MATCHING
Match the size and shape of the parasitized RBCs as they appear in Giemsa-stained thin blood smears.Answers may be used more than once.
a.Normal shape and size
b.Normal shape;size may be normal or slightly smaller
c.1.5 to 2.0 times larger than normal;oval to normal
d.60% of cells are larger than normal and oval
P.ovale

Question 12

In cases of malaria,the primary exoerythrocytic cycle occurs in the:

A)blood.
B)lung.
C)liver.
D)lymph nodes.

Question 13

Stage I of trypanosomiasis characteristically involves systemic trypanosomiasis infection without central nervous system (CNS)involvement.Lymphadenopathy is also a feature of this disease.The trypomastigotes of which protozoa are involved?

A)T.cruzi
B)T.rangeli
C)T.brucei rhodesiense
D)T.brucei gambiense

Question 14

MATCHING
Match the size and shape of the parasitized RBCs as they appear in Giemsa-stained thin blood smears.Answers may be used more than once.
a.Normal shape and size
b.Normal shape;size may be normal or slightly smaller
c.1.5 to 2.0 times larger than normal;oval to normal
d.60% of cells are larger than normal and oval
P.falciparum

Question 15

The most frequent clinical signs of chronic Chagas disease involve the enlargement of which organ?

A)Heart
B)Liver
C)Spleen
D)Lung

Question 16

MATCHING
Match the size and shape of the parasitized RBCs as they appear in Giemsa-stained thin blood smears.Answers may be used more than once.
a.Normal shape and size
b.Normal shape;size may be normal or slightly smaller
c.1.5 to 2.0 times larger than normal;oval to normal
d.60% of cells are larger than normal and oval
P.vivax

Question 17

Match the vector with the organism it infects.Answers may be used more than once.
a.Anopheles mosquito
b.Tsetse fly
c.Sandfly
d.Reduviid bug
T.rypanosoma cruzi

Question 18

MATCHING
Match the size and shape of the parasitized RBCs as they appear in Giemsa-stained thin blood smears.Answers may be used more than once.
a.Normal shape and size
b.Normal shape;size may be normal or slightly smaller
c.1.5 to 2.0 times larger than normal;oval to normal
d.60% of cells are larger than normal and oval
P.knowlesi

Question 19

A thick ring,large nucleus,and bands across the cell and 6 to 12 merozoites in a mature schizont are all characteristics of which Plasmodium spp.?

A)P.vivax
B)P.ovale
C)P.falciparum
D)P.malariae

Question 20

The vector Glossina palpalis group transmits the T.brucei gambiense organism.The diagnostic stage is the:

A)amastigote.
B)epimastigote.
C)trypomastigote.
D)promastigote.

Question 21

Match the vector with the organism it infects.Answers may be used more than once.
a.Anopheles mosquito
b.Tsetse fly
c.Sandfly
d.Reduviid bug
T.rangeli

Question 22

Match the vector with the organism it infects.Answers may be used more than once.
a.Anopheles mosquito
b.Tsetse fly
c.Sandfly
d.Reduviid bug
T.brucei gambiense