Parasitic Disease

Question 1

Parasites are

Answer 1

eukaryotic

multicellular and single cellular

Question 2

helminths

Answer 2

multicellular worms
macroscopic
differentiated and complex organs

Question 3

Protozoa

Answer 3

microscopic
single cell amaeba
replicate intra or extracellularly

Question 4

describe life cycle of Ascaris Lumbricoides (round worms/nematodes)

Answer 4

Life cycle:
highly resistant to environment egg
larvae develops in egg and viable for years
eggs are ingested and hatch in small intestine
larvae penetrate intestinal wall to blood stream, then lungs (bronchioles) where they move up trachea and are swallowed to return to small intestine to feed.
adult nematode lives and feeds in small intestine
lays 2X10^6 eggs/day
eggs develop outside body where not too cold <30 C 86 F

Question 5

parthenogenesis of ascaris lumbricoides (round worms/nematodes)

Answer 5

85% asymptomatic
abdominal pain/nausea
malnutrition
fever & pneumonia (hemorrhagic pneumonia)
peritonitis

Question 6

treatment of ascaris lumbricoides (round worms/nematodes)

Answer 6

albendazole - blocks tubulin polymerization and prevents glucose uptake

Question 7

Describe the geographical restriction of flukes (trematodes)

Answer 7

a Helminth

requires specific snail host which restricts distribution

Question 8

Compare the properties of intracellular parasites and describe how those properties relate to the diseases they cause

Answer 8

intracellular parasite is transmitted through vectors and are sensitive to dryness.
causes blood and tissue diseases
Cryptosporidiosis intracellular parasite
can be protozoa

Question 9

Compare the properties of extracellular parasites and describe how those properties relate to the diseases they cause

Answer 9

extracellular parasite includes
protozoa
transmitted by fecal-oral route
switches between active trophozite and dormant cyst

Question 10

what is protozoa?

Answer 10

microscopic (2-100mm), single cell amaeba, replicate intra or extracellularly
classified by locomotion

Question 11

trophozite

Answer 11

actively growing 
larger
multiply
in diarrhea
motile
non-infectious

Question 12

cyst

Answer 12

smaller 
dormant 
resistant to heat and dryness
infectious
in solid feces

Question 13

Describe the life cycle of Entamoebaehistolytica

Answer 13

Life cycle of Entamoebaehistolytica:
cysts is ingested through contaminated food/water
Excystation in small intestine and infects large intestine
becomes trophyzoite (causes colitis & liver abscess)
encystation in colon
excreted in feces
repeats

Question 14

how are protozoa classified?

Answer 14

by locomotion

1. Ameoebas - cytoplasmic projections
2. flagellates - rotate flagella
3. ciliates - beat hair like cilia
4. Sporozoa - non motile adult forms

Question 15

pathology, diagnosis and treatment of Entamoebae histolytica

Answer 15

pathology - asymptomatic infection leads to excretion
invasive infection leads to desimination
diagnosis - cysts in solid feces. trophozoite in diarrhea or aspiration of liver abscess. Antibody test for invasive amebiasis
treatment -antibiotic called metronidazole

Question 16

Describe the pathology and treatment of Plasmodium

Answer 16

Treatment:
ACT
injectible artesunate followed by ACT
chloroquine if other than P. falciparum

pathology: 
enlarged liver from sporozoites entering it
enlarged spleen
jaundice
anemia from lysed RBC
fever

Question 17

Describe the pathology and treatment of Plasmodium

Answer 17

pathology: fever indicates time it takes for merozoites to divide and lyse red blood cells before another cycle of reinfection and division
causes malaria (blood infection)
Treatment:
(uncomplicated) Artemisinin-based combination therapies (ACT)
(severe) Injectable artesunate, then ACT
different than falciparum - chloroquine

Question 18

Merozoites from plasmodium

Answer 18

inavde RBC
divide asexually
mature
in 2-3 days merozoites lyse RBC and infect new RBCs

Question 19

Malaria

Answer 19

humans are only reservoir (asexual phase)

transmission by mosquito vector (sexual phase)

Question 20

Plasmodia has?

Answer 20

antigenic variation of pFEMP-1 (protein for RBC adhesion)

and not directed by DNA rearrangement

Question 21

Giardia lamblia

Answer 21

“Monkey face”

2 nuclei