Blood/Tissue Protozoa

Question 1

Life cycle of Leishmania donovani? (kala-azar)

Answer 1

Transmitted via sandflies (carry amastigotes)

• Parasite into macrophage (promastigote form)
• Move to viscera; attach reticulo-endothelial system.

Question 2

Pathogenesis of Leishmania donovani?

Answer 2

Spleen, liver, BM attacked (onset 3-12 months)

• FEVER
• Hepatosplenomegaly
• Anemia
• Predisposed to bacterial infection

Question 3

Epidemiology of Leishmania donovani?

Answer 3

Asia, S. America (India, Nepal, Bangladesh)

Dogs

Question 4

Diagnosis / Treatment of Leishmania donovani?

Answer 4

Biopsy of macrophages

Sodium stibogluconate and Amphotericin B
- Antimony-resistant parasites: Mitefosine

Question 5

Cutaneous Leishmaniasis caused by…

Answer 5

Leishmania tropica/mexicana

Doesn’t enter blood

Question 6

Pathogenesis of Leishmania tropica/mexicana?

Answer 6

Reticuloendothelial of cutaneous tissue

Papule forms on skin and leaves ulcer, disfiguring scar
- Confers immunity

Question 7

Location of Leishmania tropica/mexicana?

Answer 7

Africa, Mediterranean, Southern Asia for tropica

Central Amercian for mexicana

Question 8

Diagnosis / Treatment for Leishmania tropica/mexicana?

Answer 8

Amastigotes in skin scraping

Sodium stibogluconate (topical)

Question 9

Pathogenesis of Leishmania braziliensis?

Answer 9

Causes American Mucocutaneous Leishmaniasis

Primary lesion heals, but secondary comes later at mucocutaneous junction –> deformity

Question 10

Where is Leishmania braziliensis?

Answer 10

Mexico and S. America (surprise!)

Forest rodent, sloth, anteaters

Question 11

Diagnosis / Treatment for Leishmania braziliensis?

Answer 11

Demonstrate parasite in infected tissue

Sodium stibogluconate

Question 12

Life cycle of Trypanosoma cruzi? (Chagas Disease)

Answer 12

S./C. America - kissing bugs (Triatoma)

• Defecates on skin (parasite in feces)
• Scratched into skin
• Infect spleen, liver, heart (amastigote in the tissue)

Amastigote - cyst-like pod

Enter tissue in 1-3 months

Question 13

Pathogenesis of Trypanosoma cruzi?

Answer 13

• Romana’s sign in 1/3: swelling around eye

Acute (milder)

• Fever, swollen glands
• 10% mortality in kids (heart and brain)

Chronic

• Rupture cells in heart muscle - cardiomyopathy
• Megacolon / megaesophagus

Question 14

Epidemiology of Trypanosoma cruzi?

Answer 14

Mexico, S./C. America

Blood transfusion important

Question 15

Diagnosis / Treatment of Trypanosoma cruzi?

Answer 15

Parasite in blood
Xenodiagnosis: lab bug feeds on patient, look for parasite in bug
Serologic tests

No effective drug treatment
- Benznidazole or Nifutimox works in blood stage, NOT amastigotes

Question 16

Probably review the malaria cycle on your own…

Answer 16

Sorry!

Question 17

List the members of the Plasmodium group (malaria):

Answer 17

vivax, malariae, falciparum, ovale

Question 18

Fever of Plasmodium vivax (and ovale)?

Answer 18

Benign tertian (43% of malarias)
- Every 48 hours

Patient can have relapse

Question 19

Fever of Plasmodium malariae?

Answer 19

Quartian fever (7% of malarias)
- Merzoites break out of RBCs every 72 hours

Patient does not relapse

Question 20

Fever of Plasmodium falciparum?

Answer 20

Malignant tertian (50% of all cases)

• The deadliest malaria by far
• Asynchronous release of merozoites, random fever
• NO relapse
• Many RBC attacked

Question 21

What is blackwater fever?

Answer 21

In Plasmodium falciparum

• Massive RBC lysis
• Hemoglobin release
• Dark red urine –> renal failure

Question 22

Diagnosis of Plasmodium?

Answer 22

Parasite in blood smear

Question 23

Treatment of Plasmodium?

Answer 23

Chloroquine drug of choice (erythrocytic stage)
- Good for vivax, ovale, malariae

Chloroquine-resistant:
- Atouaquone/Proguamil (Malarone or Quinine sulfate)

If parasite in liver:
- Primaquine (vivax and ovale)

Question 24

Prevention of Plasmodium?

Answer 24

Cholorquine phosphate

If resistant:
- Mefloquine or Malarone or Doxycycline or Artemisinin