Microbiology pathogenicity: Parasites

Question 1

what is a parasite

Answer 1

animal or plant that lives on or in another animal or plant of a different type and feeds from it

Question 2

human infective types

Answer 2

arthropods
helminths and related
protozoa

Question 3

common parasites

Answer 3

scabies
lice
bed bugs

Question 4

scabies

Answer 4

caused by mites
burrows under the hosts skin
inflammatory response causes symptoms

Question 5

lice

Answer 5

small wingless insects with 6 legs and claws to grasp hair
louse eggs called nits, laid on human scalp and by live lice

Question 6

bed bugs

Answer 6

commonly found in communal sleeping environments
infest mattress and bedding
generally active at night, bite individual when they sleep

Question 7

examples of helminths in the intestine

Answer 7

roundworms
whipworms
pinworms
hookworm
threadworm
intestinal fluke
tapeworms

Question 8

examples of helminths in lymphatics

Answer 8

filarial worms

Question 9

examples of mesenteric vein helminths

Answer 9

flukes

Question 10

example of helminths in biliary ducts

Answer 10

biliary flukes

Question 11

example life cycle of protozoa

Answer 11

live in duodenum and upper jejunum
has 2 forms of morphology

Question 12

morphology of protozoa

Answer 12

trophozoite
cyst

Question 13

trophozoite

Answer 13

tennis racket shaped
dorsal surface convex
ventral surface is concave with sucking disc, falling lead motility

Question 14

cyst

Answer 14

oval
diagonal axostyle

Question 15

stages of life cycle of Giardia

Answer 15

infection acquired form
excystation
multiplication
pathogenesis
encystment
cyst metabolism
cyst viability

Question 16

protozoa specimens

Answer 16

gelatin capsules
enterotest
stool
duodenal aspiration

Question 17

microscopy of protozoa

Answer 17

trophozoites
cysts

Question 18

treatment of protozoa

Answer 18

metronidazole
tinidazole

Question 19

cryptosporidium

Answer 19

has a more complex life cycle
thick-walled oocyst with spores

Question 20

trichomonas vaginalis

Answer 20

only trophozoite form
no cyst form
sexually transmitted
men usually asymptomatic
females vaginitis purulent discharge

Question 21

diagnosis of trichomonad vaginalis

Answer 21

demonstration of trophozoites in wet films/ giemsa stained smear

Question 22

treatment for trichomonas vaginalis

Answer 22

metronidazole

Question 23

what causes malaria

Answer 23

parasite
plasmodium

Question 24

4 types of plasmodium

Answer 24

plasmodium falciparum
plasmodium vivax
plasmodium malariae
plasmodium ovale

Question 25

5 stages of plasmodium life cycle

Answer 25

transmission to human
liver stage
red blood cells stage
transmission to mosquito
mosquito stages

Question 26

transmission to human

Answer 26

mosquito injects malaria parasite (sporozoites) into the human

Question 27

liver stage

Answer 27

sporozoites invade liver cells
after 10 days thousands of merozoites emerge from liver cells into the blood

Question 28

red blood cell stage

Answer 28

merozoites invade red blood ells
after 48 hours up to 20 are released from each RBC into the blood
sexual forms of the parasite called gametocytes develop over 10 days in some RBCs

Question 29

transmission to mosquito

Answer 29

gametocytes taken up from human by mosquito

Question 30

mosquito stages

Answer 30

gametocytes mature into gametes
sexual reproduction results in formation of ookinete
ookinete forms oocyst containing thousands of sporozoites
bursts and releases sporozoites that migrate to salivary gland

Question 31

how may malaria be controlled

Answer 31

vaccines
bednets
chemotherapy