Dr. Libman -- Parasitology 1: Protozoa Flashcards
1
Q
5 protozoa that affect the intestine
A
- Entamoeba histolytica
- Giardia
- Isospora
- Cryptosporidium
- Cyclospora
2
Q
5 protozoa that have a systemic effect
A
- Malaria
- Babesia
- Toxoplasma
- Leishmania
- Trypanosoma
3
Q
2 divisions of parasites
A
Unicellular (protozoa)
Multicellular (helminthes)
4
Q
3 types of helminthes
A
- Nematodes
- Cestodes
- Trematodes
5
Q
4 nematodes that affect the intestine
A
- Strongyloides
- Ascaris
- Tricharis
- Hookworm
6
Q
2 nematodes that have a systemic effect
A
- Filaria
- Toxocara
7
Q
Cestodes that affect the intestine
A
Tapeworms
8
Q
2 cestodes that have a systemic effect
A
- Hydatid cysts
- Cysticercosis
9
Q
Trematodes that affect the intestine
A
Intestinal flukes
10
Q
2 trematodes that have a systemic effect
A
- Schistosoma
- Liver flukes
11
Q
Definition of protozoa that differentiates it from bacteria and viruses
A
“Eukaryote” as it has genetic material encased in a nuclear membrane
12
Q
Define trophozoite
A
Any stage in a protozoan’s life cycle which can ingest food. In practice, also refers to the motile form
13
Q
Define a cyst
A
The non-motile form which is protected by a distinct membrane or cyst well. This is the infective stage of the parasite
14
Q
Define excystation
A
The process of emergence of the trophozoite from the cyst
15
Q
Define pseudopod
A
Temporary cytoplasmic processes at the surface of the trophozoite
16
Q
3rd leading cause of parasitic death in the world
A
Entamoeba histolytica (amoebiasis)
17
Q
4 stages of amoebiasis
A
- Asymptomatic carrier state
- Acute amoebic dysentery
- Amoebic liver abscess
- Amoeboma
18
Q
Presentation of amoebic dysentery (3)
A
- Blood, mucousy diarrhea
- Fever
- Abdominal pain
19
Q
4 ways to diagnose amoebic dysentery
A
- Amoebic (hematophagous trophozoites) in stool
- Mixed WBCs in stool
- Patchy inflammation seen on colonoscopy
- Stool PCR or antigen capture
20
Q
Presentation of amoebic liver abscess (3)
A
- Persisting fever
- RUQ or epigastric pain and/or shoulder pain
- Rarely diarrhea
21
Q
5 ways to diagnose amoebic liver abscess
A
- Ultrasound
- Raised WBC
- Serology
- Aspirate microscopy
- Response to metronidazole 750 TID
22
Q
Drug for tissue entamoeba histolytica
A
Metronidazole
23
Q
2 drugs for bowel lumen entamoeba histolytica
A
- Diiodochlorhydroxyquin (aka Iodoquinol, Diodoquin)
- Diloxanide furoate (Furamide)
24
Q
Only source of entamoeba histolytica
A
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
