Exam3Lec4IntrotoProtozoa:BloodandTissue-DwellingProtozoa

Question 1

Which protozoa is the leading cause of mortality?

Answer 1

Malaria with 0.5 million mortality per year

Question 2

What is the mortality of tuberculosis bacteria?

Answer 2

1-1.5 million

Question 3

What is the mortality of HIV diseases/aids

virus

Answer 3

1-1.2 million

Question 4

What are 8 examples of protozoan parasites?

Answer 4

1. malaria
2. sleeping sickness
3. chagas’ diesease
4. leishmaniasis
5. toxoplasmosis
6. amebiasis
7. cryptosporidium
8. giardiasis

Question 5

What are the main divisions of protozoa?

Answer 5

1. Sporozoa: example parasite is plasmodium (malaria)
2. flagellates: example parasite is trypanosomoes (sleeping sickness, chagas’ disease)
3. amoebae= infects GI tract, example parasite it entamoeba (amebiasis)
4. ciliates (non parasitic, free living)

1-3 are parasitic

Question 6

Are protozoa eukaryotic cells?

Answer 6

yes, they have organelles such as nucleus, cytoskeleton, ER with ribosomes, golgi apparatis, mitochondria, lysosomes

Question 7

What is the pharmacological challenge of protozoan parasisties and fungi?

Answer 7

The biochemistry and cell biology is simialr of other euk cells including human cells. This results in high toxicity of many drugs against protozoan parastites and fungi. In contrast bacterial prok drugs (antibiotics) are less toxic due to prok-specific drug trgets not found in human/euk cells

Question 8

Name the 5 blood and tissue dwelling protozoan parasites. Include the disease, species of parasite, and vector/mode of transmission

Answer 8

1. Malaria (plasmodium spp; mosquitos)
2. Sleeping sickness (Trypanosoma brucei; Tsetse fly)
3. Chagas disease (Trypanosoma cruzi; triatomine bugs)
4. Leishmaniasis (Leishmania spp; sandflies)
5. Toxoplasmosis ( Toxoplasma gondii; oral or fecal-oral infection)

Question 9

What is the parasite, transmision, and mortality of malaria?

Answer 9

Parasite: Plasmodium spec.
Transmission: mosquito insect vector
0.5 million deaths per year
1300 die each day
Mostly African children below the age of 5

mosquitos are most active in the nightime

Question 10

Malaria is usually restricted to what geographical area?

Answer 10

tropical and subtropical areas and altitudes below 1,500 m

Question 11

Explain the Malaria life-cycle

come back to this

Answer 11

1. The malaria parasite life cycle involves two hosts. During a blood meal, a malaria-infected female Anopheles mosquito inoculates sporozoites into the human host . Sporozoites infect liver cells and mature into schizonts , which rupture and release merozoites
2. Merozoites infect red blood cells . The ring stage trophozoites mature into schizonts, which rupture releasing merozoites

Question 12

What are the five species of plasmodium that infect humans?

Answer 12

1. Plasmodium falciparum (most severe form)
2. Plasmodium vivax (most common worldwide)
3. Plasmodium ovale
4. Plasmodium malariae
5. Plasmodium knowlesi

Question 13

Malaria disease is caused by which part of their life cycle?

Answer 13

RBC stages only

Question 14

What are poteintal mechanisms of immune defense against various Plasmodium stages?

partial immunity agasint malaria

Answer 14

• antibody
• cytotoxic T cells
• cytokines
• reactive oxygen and nitrogen intermediates

Question 15

Who does malaria affect the most?

Answer 15

• Infants and young children below age 5
• pregnant mothers
• non-immune (tourists)

Question 16

How does malaria cause disease?

Answer 16

• anemia: severe malarial anemia when hemoglobin <5g/dL; short supply of blood/unsafe blood supply)
• cerebral malaria: infected RBCs stick to capillary walls
• maternal malaria: infected RBCs stick to placenta

Question 17

What two thinfs make plasmodium falciparum malaria particulary dangerous and deadly?

Answer 17

High parasitemia of all (young and adult) RBC stages and severe cerebral malaria

Question 18

Plasmodium falciparum cytoadherance results from what?

Answer 18

Adhesion of infected RBCs to placenta (maternal malaria)

Question 19

What is the correlation of parasitemia and fever outbreaks?

Answer 19

Higher parasitemia in P. falciparum results in more severe/longer fever outbreaks

prolongs for about 2 days then neutralize, and there are peaks again

Question 20

Is it much easier to live with P virax or P falciparum and why?

Answer 20

P virax because fever quickly peaks and drops during the evening.

revisit this

Question 21

What are genetic host factors that may partially protect against malaria?

Answer 21

sickle cell trait, thalassemia, glucose-6-phosphate deydrogenase 9G6PD) deficiency