L13 - Treatment of Parasitic Diseases Flashcards

1
Q

What are the two main types of Parasite?

A

Protozoa

Metazoa

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2
Q

Describe Protoza

A

Unicellular eukaryotic organisms

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3
Q

Where are Protozoa commonly found?

A

Blood
Tissue
Intestines
Genitals

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4
Q

Describe Metazoa

A

Worms

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5
Q

What are the three types of Metazoa?

A

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

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6
Q

What are the two types of Nematodes?

A

Intestinal

Tissue

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7
Q

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

A

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

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8
Q

What species transmits Malaria?

A

Female Anopheles mosquito

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9
Q

What is the life cycle of Malaria?

A
Mosquito to
Sporozoite to
Schizont to
Trophozoite to
Merozoite to
Gametocytes
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10
Q

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

A

Sporozoite

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11
Q

How are Sporozoites mopped up?

A

By the liver, become Schizonts

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12
Q

What stage of the life cycle infects RBCs?

A

Trophozoites

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13
Q

What is a merozoite?

A

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

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14
Q

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

A

Gametocytes, these then fuse within the mosquito

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15
Q

What do the Trophozoites infecting RBCs look like?

A

Small rings

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16
Q

What is the antibiotic treatment for P. falciparum?

A

Quinine + Doxycycline/Clindamycin

Atovaquone/Proguanil (mild)

Artemisinin Derivatives - Lumefantrine/Amodiaquine/Piperaquine

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17
Q

What is the antibiotic treatment for benign species of Malaria?

A

Chloroquine + Primaquine (hypnozoites)

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18
Q

What are the fundamental aims in malarial therapy?

A

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

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19
Q

What is the MoA of Doxycycline/Clindamycin?

A

Antibacterials affecting protein synthesis

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20
Q

What is the MoA of Proguanil?

A

Proguanil affects folate synthesis

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21
Q

What is a Parasitophorous vacuole?

A

Host membrane around the parasite within a RBC

22
Q

How does the malaria parasite interact w/ Haemoglobin?

A

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

23
Q

What is the MoA of Chloroquine/Quinine?

A

Inhibits Haem Polymerase, elevating toxic Haem

24
Q

How does resistance to Chloroquine arise?

A

Plasmodium derived efflux transporter in Parasitophorous vacuole upregulated

25
Q

What is the resistance to treatment for benign species?

A

No significant resistance

26
Q

Describe the spread of Chloroquine resistance

A

Widespread

Maps to Pmfdr1 gene on Chr5 (encodes for transporter)

27
Q

Describe the spread of Quinine resistance

A

P. falciparum still generally sensitive to quinine

28
Q

Describe the consequences of treatment with Artemisin derivatives

A

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

29
Q

Describe Malaria prophylaxis

A

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

30
Q

Describe African Trypanosmomiasis

A

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

31
Q

Describe the treatment for African Trypanosmomiasis

A

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

32
Q

Describe S. American Trypanosmoiasis

A

Vector - Reduviid bug

Causes SM damage (Romana’s sign)

33
Q

Describe the treatment for S. American Trypanosmoiasis

A

Oral treatment

Benznidazole + Nifurtimox

34
Q

What is the vector for Leishmaniasis?

A

Sandfly

35
Q

What are the three types of Leishmaniasis?

A

Cutaneous
Mucocutaneous
Visceral

36
Q

Describe the treatment for Leishmaniasis

A

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

37
Q

Describe Toxoplasmosis presentation

A

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

38
Q

What is the treatment for Toxoplasmosis?

A

Pyrimethamine
Sulphadiazine
Folinic acid

39
Q

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

A

Entamoeba histolytica
Giardia
Trichomonas

40
Q

What luminal protozoa can be treated with Co-trimoxazole?

A

Cyclospora

41
Q

What luminal protozoa can be treated with Nitazoxanide?

A

Cryptosporidiosis

42
Q

Give four examples of common intestinal nematodes

A

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

43
Q

What antibiotics are used to treat intestinal nematodes?

A

Mebendazole/Albendazole

44
Q

Describe Strongyloides

A

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

45
Q

What is the treatment for Strongyloides?

A

Ivermectin

46
Q

Describe Onchocerciasis

A

Vector - Blackfly

Causes river blidness

47
Q

What is the treatment for Onchocerciasis?

A

Two doses of Ivermectin 6m apart (every 3 years)

Occasionally combined with nodulectomy

48
Q

What are the side effects associated with microfilaria killing?

A
Fever
Itch
Oedema
Arthritis
Lymphadenopathy
49
Q

Describe Lymphatic Filariasis

A

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

50
Q

Describe the common cestodes (tapeworms)

A

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

51
Q

Describe Schistosomiasis

A

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