Dr. Libman -- Parasitology 1: Protozoa Flashcards Preview

Block G -- Infection > Dr. Libman -- Parasitology 1: Protozoa > Flashcards

Flashcards in Dr. Libman -- Parasitology 1: Protozoa Deck (97)
1

5 protozoa that affect the intestine

  1. Entamoeba histolytica
  2. Giardia
  3. Isospora
  4. Cryptosporidium
  5. Cyclospora

2

5 protozoa that have a systemic effect

  1. Malaria
  2. Babesia
  3. Toxoplasma
  4. Leishmania
  5. Trypanosoma

3

2 divisions of parasites

Unicellular (protozoa)

Multicellular (helminthes)

4

3 types of helminthes

  1. Nematodes
  2. Cestodes
  3. Trematodes

5

4 nematodes that affect the intestine

  1. Strongyloides
  2. Ascaris
  3. Tricharis
  4. Hookworm

6

2 nematodes that have a systemic effect

  1. Filaria
  2. Toxocara

7

Cestodes that affect the intestine

Tapeworms

8

2 cestodes that have a systemic effect

  1. Hydatid cysts
  2. Cysticercosis

9

Trematodes that affect the intestine

Intestinal flukes

10

2 trematodes that have a systemic effect

  1. Schistosoma
  2. Liver flukes

11

Definition of protozoa that differentiates it from bacteria and viruses

"Eukaryote" as it has genetic material encased in a nuclear membrane

12

Define trophozoite

Any stage in a protozoan's life cycle which can ingest food. In practice, also refers to the motile form

13

Define a cyst

The non-motile form which is protected by a distinct membrane or cyst well. This is the infective stage of the parasite

14

Define excystation

The process of emergence of the trophozoite from the cyst

15

Define pseudopod

Temporary cytoplasmic processes at the surface of the trophozoite

16

3rd leading cause of parasitic death in the world

Entamoeba histolytica (amoebiasis)

17

4 stages of amoebiasis

  1. Asymptomatic carrier state
  2. Acute amoebic dysentery
  3. Amoebic liver abscess
  4. Amoeboma

18

Presentation of amoebic dysentery (3)

  • Blood, mucousy diarrhea
  • Fever
  • Abdominal pain

19

4 ways to diagnose amoebic dysentery

  • Amoebic (hematophagous trophozoites) in stool
  • Mixed WBCs in stool
  • Patchy inflammation seen on colonoscopy
  • Stool PCR or antigen capture

20

Presentation of amoebic liver abscess (3)

  • Persisting fever
  • RUQ or epigastric pain and/or shoulder pain
  • Rarely diarrhea

21

5 ways to diagnose amoebic liver abscess

  1. Ultrasound
  2. Raised WBC
  3. Serology
  4. Aspirate microscopy
  5. Response to metronidazole 750 TID

22

Drug for tissue entamoeba histolytica

Metronidazole

23

2 drugs for bowel lumen entamoeba histolytica

  • Diiodochlorhydroxyquin (aka Iodoquinol, Diodoquin)
  • Diloxanide furoate (Furamide)

24

Only source of entamoeba histolytica

Humans

25

Entamoeba histolytica transmission

Fecal-oral (poop the eggs and then eat the eggs)

26

Most commonly diagnosed enteric parasite in US/Canada

Giardia lamblia

27

Effect of giardia lamblia on intestinal wall

  • Villus atrophy
  • Crypt hyperplasia

28

Transmission of giardia

Fecal oral; zoonotic (most mammals, esp. beaver)

29

7 symptoms of giardiasis

  1. Diarrhea
  2. Flatulence
  3. Abdominal cramps
  4. Decreased appetite
  5. + weight loss
  6. + nausea
  7. NO fever

Basically, upper GI symptoms (colitis very unlikely dDx)

30

Signs of giardiasis

Mild abdominal tenderness

31

4 laboratory findings of giardiasis

  • No leukocytes in stool
  • No mucous in stool
  • Giardia cysts/trophs intermittent in stool
  • Girdia cysts/trophs in duodenal aspirate

32

Define anchovy paste and when you can find it

Aspirate of liver amoebic liver abscess

33

6 treatments for giardia

  1. Metronidazole 250 - 750 mg TID x 7 - 10 days
  2. Tinidazole
  3. Nitazoxanide
  4. Paromomycin
  5. Quinacrine (atabrine)
  6. Furazolidone

34

What is Cryptosporidium parvum an important cause of

Self-limited foodborne diarrhea worldwide

35

2 methods of transmission of cryptosporidium

  1. Zoonosis (bovine)
  2. Fecal-oral (i.e. by contamination of municipal water)

36

Location of cryptosporidium in body

Small intestine epithelial cell membrane

37

Type of life cycle that cryptosporidium has

Apicomplexa

38

2 clinical findings of cryptosporidium

  • Diarrhea 2 - 3 weeks (chronic in AIDS)
  • Cholecystitis

39

Taxonomy of cyclospora cayetanensis

Apicomplexa

40

Epidemiology of cyclospora cayetensis (3 points)

  • Travellers to tropics (esp. Nepal, Americas)
  • Raspberries
  • Basil from Guatemala and Mexico

41

Location of cyclospora cayetanensis in body

 Small intestine epithelial cells

42

Clinical presentation of cyclospora cayetanensis

Prolonged diarrhea (2 - 6 weeks)

43

Cyclospora cayetanensis treatment

Septra

44

Treatment for cryptosporidium

  • HIV-neg = nitazoxanide optional
  • HIV-pos = HAART!

45

4 intestinal protozoa for which we stain with hematoxylin

  1. E. histolytica
  2. Giardia
  3. D. fragilis
  4. Isospora

46

2 intestinal protozoa for which we stain using modified Ziehl-Neelsen

  1. Cryptosporidium
  2. Cyclospora

47

Intestinal protozoa for which we stain with trichrome

Microsporidium

48

Giardia taxonomy

Mastigophora

49

Trichomonas vaginalis taxonomy

Mastigophora

50

Trichomonas vaginalis transmission

  • Human reservoir
  • Urogenital tract, sexual transmission

51

Biology of Trichomonas vaginalis

Inflammation of vaginal and urethral epithelium

52

Clinical presentation of Trichomonas vaginalis (5)

  1. Asymptomatic
  2. Foul per vagina discharge
  3. Dyspareunia
  4. Adbominal cramps
  5. Pre-term birth

53

Treatment of Trichomonas vaginalis

Metronidazole

54

Taxonomy of toxoplasma gondii

Apicomplexa

55

Definitive host of toxoplasma gondii

Cat

56

Define definitive host

A host in which the parasite reaches maturity and, if possible, reproduces sexually

57

Define reservoir host

Can harbour a pathogen indefinitely with no ill effects. A single reservoir host may be reinfected several times

58

Define secondary or intermediate host

A host that harbors the parasite only for a short transition period, during which (usually) some developmental stage is completed

59

Reservoir form of toxoplasma gondii and where is it is found

Cyst (bradyzoite) in many animals and birds

60

3 modes of transmission of toxoplasmosis

  1. Fecal oral from cat
  2. Oral (raw meat)
  3. Transplacental during acute infection

61

4 clinical forms of toxoplasmosis

  1. Lymphadenopathic/acute
  2. Ocular
  3. Neonatal
  4. In immunocompromised host

62

3 signs and symptoms of lymphadenopathic toxoplasmosis

  1. Fever
  2. Lymphadenopathy
  3. Fatigue

63

Duration of lymphadenopathic toxoplasmosis

1 - 4 weeks

64

2 sources of lymphadenopathic toxoplasmosis

  1. Raw meat
  2. Kitty litter

65

2 signs and symptoms of ocular toxoplasmosis

  1. Decreased vision
  2. Retinal lesions on retinoscopy

66

3 sources of ocular toxoplasmosis

  1. Intrauterine infection
  2. Raw meat
  3. Kitty litter

67

Signs and symptoms of neonatal toxoplasmosis

Mother has lymphadenopathic toxoplasmosis (fever, nodes and/or fatigue)

68

Trend of transmission risk of neonatal toxoplasmosis in pregnancy

Increases with duration of pregnancy

69

Trend of sequelae severity of neonatal toxoplasmosis relative to the duration of pregnancy

Decreases with duration of pregnancy (i.e. if infected earlier, more severe)

70

3 treatments for toxoplasmosis

  1. Pyrimethamine po 200 mg for 1 day THEN 100 mg od for 4 weeks
  2. Sulfadiazine po 4 mg od for 4 weeks
  3. Folinic acid po 5 mg for 4 weeks

71

Taxonomy of leishmania

Mastigophora

72

Taxonomy of trypanosoma

Mastigophora

73

3 forms of leishmania

  1. Cutaneous
  2. Mucocutaneous
  3. Visceral

74

2 forms of trypanosoma

  1. African sleeping sickness
  2. South American Chagas disease

75

Type of transmission pathway taken by hemoflagellates (trypanosoma and leishmania)

Zoonotic (man and livestock)

76

3 basic morphologic stages of trypanosoma and leishmania

  1. Motile promastigote
  2. Trypomastigote
  3. Immotile amastigote

77

2 distinguishing features of trypanosoma and leishmania

  • Kinetoplast
  • Flagellum

78

Definitive host of leishmania

Human

79

Leishmania vector

Sandfly

80

Leishmania reservoir

Dog, gerbil

81

4 methods of diagnosis and for which types of hemoflagellates they cover

  1. Biopsy
    • Granuloma
    • Impression smear stain --> amastigotes
  2. Aspirate and stain = amastigotes
  3. Aspirate culture = promastigotes
  4. Aspirate or biopsy
    • PCR

82

2 types of leishmania responsible for the cutaneous form

  • L. tropica
  • L. major

83

2 types of leishmania responsible for mucocutaneous leishmaniasis

  • L. (V.) braziliensis complex
  • L. (L.) mexicana complex

84

2 types of leishmania responsible for visceral leishmaniasis

  • L. infantum
  • L. donovani

85

5 relatively common clinical manifestations of visceral leishmaniasis

  • Fever
  • Hepatomegaly
  • Splenomegaly
  • Cough
  • Lymphadenopathy (inguinal, axillary, post-cervical)

86

3 rare clinical manifestations of viscerla leishmaniasis

  • Nephrotic syndrome
  • Symptomless generalized lymphadenopathy
  • Mucocutaneous lesions in Africa

87

6 treatments for visceral leishmaniasis

  1. Liquid nitrogen
  2. Ketoconazole/fluconazole
  3. Pentostam (sodium antimony gluconate) IV
  4. Amphotericin B IV
  5. Liposomal Ampho B
  6. Miltefosine po

88

Distribution of trypanosomiasis in sub-Saharan Africa

  • West = gambiense
  • East = rhodesiense

89

Difference between the gambiense and rhodesiense types of trypanosoma brucei

  • Rhodesiense = more virulent
  • Gambiense = more chronic

90

Typical vector for trypanosoma

Tsetse fly

91

Reservoir for East African trypanosomiasis

Bush buck 

92

3 types of clinical findings associated with Africna trypanosomiasis

  1. Chancre (painless ulceration)
  2. Parasitemia
  3. Organ-specific symptoms

93

7 symptoms related to parasitemia due to African trypanosomiasis

  1. Periodic fever
  2. Headache
  3. Joint and muscle pain
  4. Lymphadenopathy
  5. Weight loss
  6. Pruritis
  7. Anemia

94

4 edema-related symptoms of African trypanosomiasis

  1. Peripheral
  2. Ascites
  3. Pulmonary
  4. Pericardial

95

3 cardiac symptoms of African trypanosomiasis

  1. ECG changes
  2. CHF
  3. Cardiac distension

96

2 GI symptoms of African trypanosomiasis

  1. Diarrhea
  2. Anorexia

97

4 neurologic symptoms of African trypanosomiasis

  1. Focal neurologic defects
  2. Confusion
  3. Lethargy
  4. Coma