blood parasites

Question 1

Plasmodium species

Answer 1

vivax, falciparum, malariae, ovale

5th species- knowlesi (infection of old world monkeys)

Question 2

malaria vector

Answer 2

femal anopheles, blood meal -. introduces sporozoites

Question 3

malaria life cycle

Answer 3

liver cell infected (schizont ruptures releasing merozoites) -> human blood stages (trophozoite) matures to schizont and gametocytes
schizonts rupture more merozoites
or develop in to gametocytes
gametocytes taken up by mosquito
form oocyst release sporozoites

Question 4

erythrocytic cycle

Answer 4

fever, chill syndrome (release of toxic material)

10-15 min chills, 2-6 hr feverish period`

Question 5

erythrocytic cycle length

Answer 5

P. vivax- 48 hrs (benign tertian)
P. falciparum- 48 hrs (malignant tertian)
P. malariae- 72 hrs (benign quartan)
P. ovale- 48 hrs

Question 6

Relapsing infections

Answer 6

P. vivax usually first to year
P. ovale
P. malariae- recrudescence possible for up to 50 years
true relapse* no parasitemia (hypnozoites in the liver)

Question 7

Diagnosis of malaria

Answer 7

thick and thin blood smears
must see blue cytoplasm, red chromatin, pigment
Thick smear- lyse rbc and concentrate (sensitive)
thin smear- examination of rbc (whole blood picture)

Question 8

Diagnostic Features

Answer 8

RBC size
Stages seen
Rings: size, number, texture
trophs: shape
gametocytes: shape, present or not
Pigment: stippling, Mauer's dots, Schuffner's dots
number of merozoites in a schizont

Question 9

p. vivax

Answer 9

ring- robust
troph-ameboid
12-24 merozoites

Question 10

p. falciparum

Answer 10

cause of cerebral malaria
can be doubly infected
normally only ring and final gametocyte
doubly infected

Question 11

p. malariae

Answer 11

recrudescence up to 50 years
infect older rbc (normal size)
rosette form- schizont (6-10 merozoite)- cluster of pigment in the center
band form (

Question 12

p. ovale

Answer 12

rbc oval, fimbrinated
schizont- (6-14 merozoites)schuffner’s dots
troph not as vivacious

Question 13

Babaesia

Answer 13

bite of various ticks
humans are accidental host
Ixodes ticks

Question 14

Babesia life cycle

Answer 14

rodent & tick (humans are dead end)
sprozoites introduced, developed in to trophozoite differentiate to merozoites and gametocytes
sexual reproduction in tick (definitive host) sprogony

Question 15

Babesia ID

Answer 15

resemble ring forms of Malaria, but with more variability
confused with P. falciparum (never make malaria-like pigment
“Maltese cross”
GIEMSA

Question 16

Trpanosoma brucei

Answer 16

Tsetse flies
two subspecies gambiense, rhodisiense (cannot differentiate)
gamibense 90%

Question 17

T. brucei Life Cycle

Answer 17

tsetse flies of genus GLOSSINA

when fly bites METACYCLE TRPYOMASTIGOTES are inoculated

Question 18

Trypomastigote

Answer 18

highly pleomorphic
free flagellum, small kinetoplast, prominent undulating membrane
30 um
short form w/o flageullum

Question 19

Epimastigote

Answer 19

in tsetse fly

Question 20

Trypanosoma cruzi

Answer 20

Chagas Disease, American Trypanosomiasis
Ramona’s sign, amastigotes vs. epimastigotes
blood stream trypomastigotes do not multiply

Question 21

t. cruzi trypomastigote

Answer 21

large kinetoplaste
c or u shaped
20 um

Question 22

Leishmania

Answer 22

Kala-azar (visceral, cutaneous, mucocutaneous leishmaniasis)
bite of sandfly (phlebotomus)
NO SEXUAL STAGE

Question 23

Visceral leishmaniasis organisms

Answer 23

l. donavoni, l. infantum, l. chagasi

orgaisms multiply in tissue macrophages, liver, spleen

Question 24

cutaneous leismaniasis organisms

Answer 24

l. Mexicana, l. tropica, l. aethiopica

infection at site of bite producing a firm painless papule

Question 25

mucocutaneous leishmanisis organisms

Answer 25

l. braziliensis

starts with cutaneous, amastigotes pread to mouth, nose, lips and cause erosion

Question 26

visceral leishmania symptoms

Answer 26

hepatosplenomegaly, lymphadenopathy

Question 27

Promastigotes

Answer 27

infective stage for humans, flagella is anterior
occurs in sandfly and in culture
10-15 um long, large kinetoplast

Question 28

Leishman-Donovan body

Answer 28

reticuloendothelial cells

round to oval, large nucleus and prominent rod-shaped kinetoplast