Introduction to Parasites Flashcards
1
Q
What are the characteristics of protozoa?
A
Unicellular, aerobic heterotrophs, present where there is a lot of water, reproduce by budding, schizogoy and sex and can produce cysts
2
Q
What is schizogony?
A
Multiple division of the nucleus before cell division
3
Q
Where would you find entamoeba histolytica?
A
Poorly sanitized environment and around homosexual males
4
Q
Which amoeba is the only pathogenic among all intestinal amoebae?
A
Entamoeba histolytica
5
Q
Mammals can be infected with entamoeba histolytica but;
A
do not shed cysts with their feces
6
Q
Where does the trophozoite entamoeba histolytica of exist?
A
Only in the host and fresh feces
7
Q
Where do the cysts of entamoeba histolytica survive?
A
Outside of the host in water and soils and on food
8
Q
How many nuclei does the trophozoites of entamoeba histolytica have? The cysts?
A
1, 4
9
Q
What are the clinical manifestations of entamoeba histolytica?
A
Asymptomatic carriers
Collitis and deep, tear drop ulcer formation
Watery stool with mucus and blood
Extra-intestinal infection
10
Q
How is entamoeba histolytica treated?
A
Metronidazole
11
Q
Where would you find giardia lamblia and how is it translated?
A
Lakes, streams, prisons and day cares
Fecal-oral
12
Q
What is the reservoir for giardia lamblia?
A
Human and animals where cysts are in the feces
13
Q
How many nuclei does the giardia lamblia trophozoite have? The cyst?
A
2, 4
14
Q
What does giardia lamblia cause and how does it do this?
A
Malabsoprtion because the organism coats the distal villi
15
Q
What are the clinical signs of giardia lamblia?
A
Watery, foul smelling diarrhea Cramps and flatulence Abdominal distention Disaccharidase deficiency (lactose intolerance) Dehydration
16
Q
What happens with pts who have an IgA deficiency who acquire giardia lamblia?
A
Predisposed to symptomatic infection
17
Q
What is cryptosporidium parvum and what is it associated with?
A
GI protozoa
Diarrhea in the immunocompromised
18
Q
Where can you find cryptosporidium parvum and why there?
A
Public swimming pools because its resistant to chlorine
19
Q
In an immuno-competent person what would cryptosporidium parvum cause?
A
Mild-self limiting entercolitis (diarrhea, vomiting, ab pain) and spontaneous remission
20
Q
If an immunocompromised pt acquires cryptosporidium parvum what could happen to them?
A
50 or more stools per day
Dehydration
Lasts for months
Common in AIDS patients
21
Q
What is the treatment for cryptosporidium parvum?
A
Self-limiting in healthy
Lethal in AIDS
No effective therapy
maybe azithromycin
22
Q
What type of parasite is a toxoplasma gondii?
A
Apicomplexa
23
Q
What is the host for toxoplasma gondii?
A
Kitties
24
Q
How does toxoplasma gondii reproduce?
A
Asexually and sexually inside the cells
25
What is the role of human in toxoplasma gondii?
Intermediate host
26
In the asexual tissue cycle, toxoplasma gondii enters a phase of motility and can produce disease. It's called;
Tachyzoites
27
The non-motile phase of toxoplasma gondii is called;
Bradyzoites
28
If a pt who is immunocompromised contacts toxoplasma gondii what would you see in terms of symptoms?
Focal neurological deficits, tetinochoroditis or pneumonitis
29
If a pregnant mother has toxoplasma gondii what could happen to the infant?
Hydrocephalus, heptaospenomegaly, jaundice, fever, anemia, pneumonia
30
How can toxoplasma gondii be prevented?
Clean litter box daily
| Cook meat and fish completely through
31
What are the two types of Trypansomas?
T. cruzi (america) and T. bruci (africa)
32
T. cruzi and T. bruci look very similar. Where do they both get their energy from?
A kinetoplast
33
Where would you be likely to find Tryanosoma cruzi?
Central and South America
34
What transmits T. cruzi?
Reduviid - kissing bug
35
What is the inflammation at the site of infection called when made by the thing that transmits T. cruzi?
Chagoma
36
What is Romana's sign for T. cruzi?
Painless perobital swelling
37
What is the clinical manifestation of tryansoma cruzi?
Chaga's disease
38
What are the chronic symptoms associated with T. cruzi?
2/3 of patients will have dialated cardiomyopathies
| 1/3 of patients present with megacolon and megaesophagus
39
What is the treatment for T. cruzi?
Nifurtimox
40
What transmits T. bruci?
The glossina fly/ Tse Tse fly
41
When the lymph becomes englarged due to a T.bruci infection what is it called?
Winterbottom's sign
42
What is the clinical manifestion of T. bruci?
African sleeping sickness
43
How can T. bruci cause CNF problems?
Because it can cross the blood brain barrier
44
What are the symptoms of African sleeping sickness?
Tremors of tongue and eyelids
Mental dullness and progressive apathy
Neurological symptoms
Rapid weight loss, anemia and coma
45
What are the cutaneous forms of leishmania?
L. tropica
L. major
L. aethiopica
L. mexicana
46
What is the visceral leishmania?
L. donovani
47
What is the mucocutaneous leishmania?
L. brazilliensis
48
What is the the treatment for T. bruci?
Suramin
49
How is Leishmania transmitted?
Sand flies
Animal to human
Human-sandfly-human
50
What are the clinical manifestations of cutaneous leishmaniasis?
Most common form, relatively benign self-healing skin lesions
51
What are the clinical manifestations of muscocutaneous leishmaniasis?
Simple skin lesions that metastasize to mucosae (nose and mouth)
52
What is the clinical manifestation of viseral leishmaniasis?
Kala-Azar fever
Skin, lymph, bone marrow, liver and spleen invovlement
Generalized infection of the reticuloendothelial system, hepatosplenomegaly
High mortality
53
If you saw a helmenth what clues would let you know it was a cestode?
Segmented plane
No body cavity or digestive tube
Hermaphroditic
Oral suckers, botridias and double rostellar hooks
54
What features would be expected of a trematode?
```
Unsegmented plane
No body cavity
Digestive tube ending in a cecum
Hermaphroditic except Schistosoma
Oral suckers and ventral suckers
```
55
What features would be expected from a nematode?
Cylindrical
Body cavity and digestive tracks that ends with anus
Dioecious
Lips, teeth, extremities and dentary planes
56
What is the colloquial name for cestodes?
Tapeworms
57
What are the general characteristics of cestodes?
Scolex (head)
Segmented body and suckers
Eosinophillia
58
What specific features would you see of taenia saginata (beed tapeworm)?
Scolex with 4 suckers
No hooks
Usually asymptomatic
59
Where would you find the cysticosis for Taenia saginata?
Cow muscle which are infected by human waste
| Humans are the host only to the adult worm
60
What specific features would you see of Taenia solium (pork tapeworm)?
Scolex with 4 suckers and circle of hooklets
61
What is the treatment for taenia saginata?
Praziquantel
| Albendazole
62
At what stage of the taenia solium life cycle are humans the host?
Definitive or intermediate host
63
What are the clinical manifestation of taenia solium?
Adult worms generally asymptomatic
Larvae penetrate intestines, enter blood and encyst the brain leading to hydrocephalus, motor spasm, loss of vision, meningitis, seizures
Larvae that encyst other organs are generally asymptomatic
64
Where is taenia solium prevalence high?
Mexico
65
What is the treatment for taenia solium?
Praziquiantel and Albendazole can kills cysts but death of larvae may cause inflammation
Corticosteroids vs. edema and inflam
66
How could Diphyllobothrum latum (fish tapeworm) be visualized?
Yellow with dark markings
3 -15 m long
Long life span
Scolex with 2 sucking grooves
67
How do crustaceans aquire D. latum and who becomes a host?
Ingest eggs in fresh water
| Humans and dogs
68
What is the host cycle for D.latum?
1st intermediate - crustacean
2nd intermediate - fish
Definitive - human
69
What are the specific life stages of the D. latum?
Coracidium (egg in feces)
Procercoid (in crustacean)
Plerocercoid larvae (in fish)
70
What are the clinical signs of D. latum?
Asymptomatic mostly
Abdominal discomfort and cramps
Diarrhea and constipation cycles
Megaloblastic anemia - dec B12
71
What is the treatment for D. latum?
Praziquantel
72
What are the general properties of Echinococcus granulosus (dog tapeworm)?
Found in dogs and sheep
Scolex with 3 proglottids
Rostulum 4 suckers
2 rows of hooks
73
What are the clinical manifestation of E. granulosus?
Hydatid cysts
Occurs when hyadid cyst is 8-10cm
Travel from liver to brain to and once big enough can compress vital structures and erode into biliary tact or bronchus
Fever and hypotension
74
What is the most common tape worm in the US?
Hymenolepsis nana (dwarf tapeworm)
75
Where does H. nana complete its life cycle?
Both larval and adult forms maybe be found in humans
76
What is the direct transmission of H. nana?
Ingestion of effs that hatch in duodenum (autoinfection)
77
What is the indirect transmission of H. nana?
Ingestion of ingested arthropod
78
What are the symptoms of H. nana?
Praziqantel
79
How would nematodes (round worms) be characterized?
Unsegmented, bilaterally symmetric, body "cuticle", triploblastic (fluid filled cavity, psudeocoelom, hydrostatic skeleton)
Can be free living
80
What does the digestive tract of a nematode look like?
Complete
81
Nematodes are dioecious, but how do you tell a man wiggly from a lady wiggly?
Males have a bent tail and females do not
82
Which is one of the largest nematodes in the world?
Ascaris lumbricoides
83
How could an infection of ascaris lumbricoides be obtained?
Soil contaminated with human feces
84
What is the pathogenesis of ascaris?
Ingestion of eggs > Eggs hatch in small intestine > Larvae released > Penetrate intestinal wall > Portal circulation > Liver > Heart > lungs > from lungs coughed up and swallowed > back to intestines as adult
85
What are the clinical signs for ascaris lumbricoides?
Migration - hemorrhagic/ eosinophillic pneumonia, cough (loeffler's syndrome)
Intestinal obstruction - intestinal rupture
Parasite proteins that are allergenic - asthma, hives
86
How could you acquire Ancylostoma duodenale?
Larvae can penetrate skin, generally through people walking barefoot
87
Where would Ancylostoma duodenale be found in the body and what does it cause?
It attaches to GI mucous causing blood and fluid loss
microcytic hypochromic iron deficiency anemia
Pot-belly, finger clubbing and PICA (eats dirt)
88
Which species does Enterobius Vermicularis (pin worms) infect?
Humans
89
Where do the Enterobius Vermicularis infect and where do they migrate to?
Colon and travel to the perianal region at night to lay eggs
90
How is a person reinfected by Enterobius Vermicularis?
By scratching the infected area
| "Pruritus ani"
91
What is the test that determines an Enterobious Vermicularis infection?
Scotch tape test
92
What is the treatment for Enterobious Vermicularis?
Albendazole kills adults
93
How could Anisakis be acquired?
Infection due to infected water or raw saltwater seafood
94
What are the symptoms associated with Aniskais?
Gastroenteritis, Eosinophilia, occult blood in stool
95
How is a person infected with Trichuris trichiura (whipworm)?
Infection from soil contaminated with human feces
96
Where does the adult form of trichuris trichiura inhabit in the host?
Cecum and large intestine
97
What are the symptoms of a trichuris trichiura infection?
Tenesmus, malnutrition, diarrhea
| Prolapse of rectum
98
Where would Strongyloides strocrailis most likely be found and how is its contracted?
Tropical areas
| Infection through ingestion or larval penetration
99
How would Strongyloides be diagnosed and what are the clinical signs?
Larva in stool, no eggs present
| Itching, blotching, wheezing (pneumo), diarrhea, weight loss
100
What parasite is associated with under-cooked pork or bear?
Trichinella spiralis
101
How is Trichinella spiralis diagnosed and what are the clinical signs?
Encysted larva in striated muscle (adult intestines)
| Trichinosis - gastroenteritis, fever, muscle pains, periorbital edema, eosinophilia
102
What would you treat Trichinella spiralis with?
Thiabendazole
103
How is Wuchereria bancrofti transmitted?
Larvae transmitted though female Anopheles mosquito bite
104
What are the clinical signs of Wuchereria bancrofti?
Filarisasis - obstruction of lymphatics leading to edema, lymphangitis, cellulites
Elephantiasis - result from chronic and repeat infection
tropical pulmonary eosinophilia
Chlyuria (microfilariae in urine)
105
What is the treatment for Wuchereria bancrofti?
Diethycarbamazine and Ivermedtin (microfilariae)
106
Where would Oncocerca volvulus be found and what transmits it?
Africa and Central America
| Transmitted by female blackfly
107
What are the clinical signs of Oncocerca volvulus?
Subcutaneous inflam and pruritus
| River blindness due to microfilariage
108
How is Oncocerca volvulus treated?
Ivermectin
109
What is Dracunculus medinensis referred to as?
Guinea Fire Worm disease
110
How can you attain Drancunculus medinensis and how do you remove it?
Drinking infected water where little crustacenas live
| Use a stick which they wrap around over the course of a few days
111
What are the characteristics of trematodes?
Dorso-ventrally flattened, unsegmented, snails are always intermediate, hermaphroditic (except blood flukes), 2 radial striated suckers, incomplete digestive tract
Most made of reproductive organs
112
Where does Fascioloa hepatica (sheep liver fluke) live in the host?
Bile ducts of sheep
113
What is the defining feature of Fasciola hepatica?
Prominent cephalic cone
114
What is the life cycle of Fasciola hepatica?
Eggs hatch and become miracidium in water which does into snails, then free swimming cercariae are released and collects on plants which are then eaten by humans
115
What are the clinical signs of Fasciola hepatica?
Biliary obstruction
Gall stones
Elevated blood bilirubin
Cirrhosis
116
Where would you find Clonocrchis sinensis (chinese liver fluke) on the earth and in the body?
Far east, southeast Asia, Russia
| Adult worms in intrahepatic biliary tract
117
How could Chonocrchis sinensis be contracted?
Eating undercooked fish
118
What are the clinical signs of Chonocrchis sinesis?
RUQ pain
Jaundice
Heptatomegaly
Adenomatus hyperplasia (Cholangiocarcinoma)
119
What is the defining visual feature of the Paragonimus westermani egg and adult?
Operculum around egg
| Adults encapsulated in a granuloma
120
If a Paragonimus westermani cyst ruptures what symptoms may occur?
Cough and chest pain
121
What are the clinical signs of Paragonimus westermani?
Cerebral paragonimiasis
| Head aches, fever, nausea, visual disturbances and convulsive seizures
