L13 - Treatment of Parasitic Diseases

Question 1

What are the two main types of Parasite?

Answer 1

Protozoa

Metazoa

Question 2

Describe Protoza

Answer 2

Unicellular eukaryotic organisms

Question 3

Where are Protozoa commonly found?

Answer 3

Blood
Tissue
Intestines
Genitals

Question 4

Describe Metazoa

Answer 4

Worms

Question 5

What are the three types of Metazoa?

Answer 5

Nematodes (roundworms)
Cestodes (tapeworms)
Trematodes (flukes)

Question 6

What are the two types of Nematodes?

Answer 6

Intestinal

Tissue

Question 7

What four species of Protoza cause Malaria? - Which is not benign?

Answer 7

P. falciparum
P. vivax
P. ovale
P. malariae

Question 8

What species transmits Malaria?

Answer 8

Female Anopheles mosquito

Question 9

What is the life cycle of Malaria?

Answer 9

Mosquito to
Sporozoite to
Schizont to
Trophozoite to
Merozoite to
Gametocytes

Question 10

What is the first stage of Malaria that humans are initially infected with called?

Answer 10

Sporozoite

Question 11

How are Sporozoites mopped up?

Answer 11

By the liver, become Schizonts

Question 12

What stage of the life cycle infects RBCs?

Answer 12

Trophozoites

Question 13

What is a merozoite?

Answer 13

A stage of the malaria life cycle capable of initiating a new stage of development (sexual/asexual)

Question 14

What stage of the life cycle is re-taken up by mosquitos?

Answer 14

Gametocytes, these then fuse within the mosquito

Question 15

What do the Trophozoites infecting RBCs look like?

Answer 15

Small rings

Question 16

What is the antibiotic treatment for P. falciparum?

Answer 16

Quinine + Doxycycline/Clindamycin

Atovaquone/Proguanil (mild)

Artemisinin Derivatives - Lumefantrine/Amodiaquine/Piperaquine

Question 17

What is the antibiotic treatment for benign species of Malaria?

Answer 17

Chloroquine + Primaquine (hypnozoites)

Question 18

What are the fundamental aims in malarial therapy?

Answer 18

Combination therapy
Completion of course
i.v. for severe malaria

Question 19

What is the MoA of Doxycycline/Clindamycin?

Answer 19

Antibacterials affecting protein synthesis

Question 20

What is the MoA of Proguanil?

Answer 20

Proguanil affects folate synthesis

Question 21

What is a Parasitophorous vacuole?

Answer 21

Host membrane around the parasite within a RBC

Question 22

How does the malaria parasite interact w/ Haemoglobin?

Answer 22

Breaks it down to Haem + Globin
Globin is desired, Haem is toxic
Haem Polymerase clumps Haem (Haemozoin)

Question 23

What is the MoA of Chloroquine/Quinine?

Answer 23

Inhibits Haem Polymerase, elevating toxic Haem

Question 24

How does resistance to Chloroquine arise?

Answer 24

Plasmodium derived efflux transporter in Parasitophorous vacuole upregulated

Question 25

What is the resistance to treatment for benign species?

Answer 25

No significant resistance

Question 26

Describe the spread of Chloroquine resistance

Answer 26

Widespread | Maps to Pmfdr1 gene on Chr5 (encodes for transporter)

Question 27

Describe the spread of Quinine resistance

Answer 27

P. falciparum still generally sensitive to quinine

Question 28

Describe the consequences of treatment with Artemisin derivatives

Answer 28

Shorter parasite clearance times Reduced gametocyte numbers/circulation time Little toxicity Should be used in combination

Question 29

Describe Malaria prophylaxis

Answer 29

High Risk - Mefloquine, Malarone, Doxycycline Moderate Risk - Chloroquine + Proguanil Low Risk - Chloroquine

Question 30

Describe African Trypanosmomiasis

Answer 30

Vector - Tsetse fly Resevoir - Cattle CNS Invasion causes sleeping sickness

Question 31

Describe the treatment for African Trypanosmomiasis

Answer 31

Treatments are toxic, given i.v. Stage 1 - Suramin, Pentamidine Stage 2 - Melarsoprol, Eflornithine + Nifurtimox

Question 32

Describe S. American Trypanosmoiasis

Answer 32

Vector - Reduviid bug | Causes SM damage (Romana's sign)

Question 33

Describe the treatment for S. American Trypanosmoiasis

Answer 33

Oral treatment | Benznidazole + Nifurtimox

Question 34

What is the vector for Leishmaniasis?

Answer 34

Sandfly

Question 35

What are the three types of Leishmaniasis?

Answer 35

Cutaneous Mucocutaneous Visceral

Question 36

Describe the treatment for Leishmaniasis

Answer 36

Sodium Stibogluconate (i.m.) AmB (i.v.) Miltefosine (oral)

Question 37

Describe Toxoplasmosis presentation

Answer 37

Immunocompetent - Lymphadenopathy, fever, malaise, self-limiting Immunocompromised - Brain abscess

Question 38

What is the treatment for Toxoplasmosis?

Answer 38

Pyrimethamine Sulphadiazine Folinic acid

Question 39

What three luminal protozoa can be treated with Metronidazole/Albendazole?

Answer 39

Entamoeba histolytica Giardia Trichomonas

Question 40

What luminal protozoa can be treated with Co-trimoxazole?

Answer 40

Cyclospora

Question 41

What luminal protozoa can be treated with Nitazoxanide?

Answer 41

Cryptosporidiosis

Question 42

Give four examples of common intestinal nematodes

Answer 42

Enterobius (pin/threadworm) Ascaris Trichuris (whipworm) Hookworms

Question 43

What antibiotics are used to treat intestinal nematodes?

Answer 43

Mebendazole/Albendazole

Question 44

Describe Strongyloides

Answer 44

A protozoa capable of long term infection OR hyperinfection in the immunocompromised Cause death from Gram-ve sepsis

Question 45

What is the treatment for Strongyloides?

Answer 45

Ivermectin

Question 46

Describe Onchocerciasis

Answer 46

Vector - Blackfly | Causes river blidness

Question 47

What is the treatment for Onchocerciasis?

Answer 47

Two doses of Ivermectin 6m apart (every 3 years) | Occasionally combined with nodulectomy

Question 48

What are the side effects associated with microfilaria killing?

Answer 48

``` Fever Itch Oedema Arthritis Lymphadenopathy ```

Question 49

Describe Lymphatic Filariasis

Answer 49

Parasitic disease caused by filiarial worms that live in the lymph system. Presents with abnormal fluid balance

Question 50

Describe the common cestodes (tapeworms)

Answer 50

Taenia (beef/pork) - Treated w/praziquantel +/-

Question 51

Describe Schistosomiasis

Answer 51

Caused by Schistosomes Spread through infected water Causes abdominal swelling, pain, liver damage, kidney failure, infertility etc.