Parasitology - Protozoa

Question 1

What is a cyst?

Answer 1

Tough protective capsule around larva of a parasitic worm

Question 2

What is a trophozoite?

Answer 2

Motile form of protozoa, converted to this form after ingestion

Question 3

Which protozoa cause diarrhea?

Answer 3

• entamoeba histolytica
• giardia lamblia
• cyclospora cayetanensis
• cryptosporidium
• isospora belli

Question 4

How is entamoeba histolytica transmitted?

Answer 4

Fecal-oral transmission

Question 5

What are symptoms of entamoeba histolytica?

Answer 5

• abdo pain
• few loose stools/day
• flecks of blood and mucus in stool

Question 6

How can entamoeba histolytica affect the organs?

Answer 6

• form abscess in liver after penetrating portal circulation, then spreading to lungs forming pulmonary abscesses

Question 7

What is the treatment for entamoeba histolytica?

Answer 7

Metronidazole

Question 8

How is giardia lambda spread?

Answer 8

Contaminated drinking water from sewage

Question 9

What is schizogony?

Answer 9

Asexual reproduction by multiple fission. (Organism with multiple nuclei dividing into several unicellular entities)

Question 10

What is the pathogeny of parasites?

Answer 10

• obligate
• facultative
• opportunistic

Question 11

Morphology of entamoeba histolytica

Answer 11

• trophozoite (10-50 um)
• granules in endoplasm
• incorporated into bacteria
• RBCs
• cyst with 1-4 nuclei

Question 12

What is the pathogeny of entamoeba histolytica?

Answer 12

obligate human pathogen

Question 13

What disease does entamoeba histolytica cause?

Answer 13

Amoebic dysentery

Question 14

Disease forms of entamoeba histolytica?

Answer 14

• asymptomatic cyst excretion
• acute amoebic dysentery
• amoebic abscess
• chronic amoebiasis
• granuloma/amoeboma

Question 15

What causes malaria?

Answer 15

Plasmodium species

Question 16

What is the mode of transmission of leishmania spp.?

Answer 16

Sandflies!

Question 17

What causes African sleeping sickness?

Answer 17

Trypanosoma brucei

Question 18

How do you treat African sleeping sickness?

Answer 18

• suramin

- IF invades CNS, melarsoprol

Question 19

How is trypanosoma brucei transmitted?

Answer 19

via tsetse fly (biting human)

Question 20

What is the main diagnosis for trypanosome brucei?

Answer 20

Trypomatigotes in blood smear

Question 21

What disease does naegleria fowleri cause?

Answer 21

RAPIDLY fatal meningoencephalitis!

Question 22

What are the symptoms of sleeping sickness?

Answer 22

• enlarged lymph nodes (lymphadenomegaly)
• recurring fever
• somnolence
• coma

Question 23

What are the symptoms of Chaga’s disease?

Answer 23

• dilated cardiomyopathy (w/ apical atrophy)
• megacolon
• megaesophagus
• Romana sign (unilateral periorbital swelling)

Question 24

What organism do sandflies transmit?

Answer 24

Leishmania donovani

Question 25

How do you treat Chaga's disease?

Answer 25

-Benznidazole or - nifurtimox

Question 26

How is plasmodium spp. transmitted?

Answer 26

via anopheles mosquitoes

Question 27

What are the main symptoms of malaria?

Answer 27

- fever - headache - anemia - splenomegaly

Question 28

What are the protozoa involved with malaria?

Answer 28

Plasmodium: - vivax/ovale - falciparum - malariae

Question 29

What is chloroquine used to treat?

Answer 29

Malaria --> RBC stage

Question 30

What is primaquine used to treat?

Answer 30

Malaria --> liver stage, to get rid of the p. oval and p. vivax as they can be in the liver in dormant stages

Question 31

What is the mode of transmission of babesia?

Answer 31

Ticks

Question 32

What are symptoms of congenital toxoplasmosis?

Answer 32

- chorioretinitis - hydrocephalus - intracranial calcification

Question 33

Diagnosis of toxoplasmosis?

Answer 33

- serology: high Ig titters in ELISA

Question 34

List some symptoms of toxoplasmosis

Answer 34

- fever - lymph node, liver, and spleen enlargement - pneumonia

Question 35

What kind of patients does toxoplasmosis affect the most?

Answer 35

- immunocompromised: AIDS, cancer pts | - pregnant women (can transfer to child)

Question 36

Mode of transmission of toxoplasmosis?

Answer 36

- cysts in meat, i.e. eating undercooked pork | - oocysts in cat feces (ingested/inhaled)