04 - Parasitology Flashcards
(181 cards)
1
Q
Term: presence of an endoparasite in host
A
infection
2
Q
Term: presence of an ectoparasite in host
A
infestation
3
Q
Type of parasite that needs a host at some stage of life cycle to complete development and propagation.
A
Obligate parasite
4
Q
Type of parasite that may exist in a free-living state but becomes parasitic when the need arises
A
Facultative parasite
5
Q
This is a type of parasite that can establish itself in a host where it does not ordinarily live in.
A
Accidental or Incidental parasite
6
Q
Type of parasite which successfully invades a host but merely passes through the GI tract without colonizing it.
A
Spurious parasite
7
Q
Type of host in which the parasite attains sexual maturity.
A
Definitive (or Final) host
8
Q
Type of host which only harbors the asexual or larval stage.
A
Intermediate host
9
Q
Type of host in which the parasite does not develop further into later stage.
A
Paratenic host
10
Q
Type of host in which the life cycle of the parasite is allowed to continue and which become additional sources of human infection
A
Reservoir host
11
Q
What are vectors?
2 types of vectors, and describe.
A
Vectors transmit parasites from one host to another.
- Biologic vector - transmits a parasite only after it has completed its development (thus, also a host)
- Mechanical (or Phoretic) vector - only transports the parasite
12
Q
Term: infection wherein an infected individual is further infected with the same species, leading to massive infection
A
Hyperinfection, a.k.a. Superinfection
13
Q
What is the cause/origin of congenital toxoplasmosis?
A
Exposure of mother to cats during pregnancy
14
Q
enumerate: virulence factors of Entamoeba histolytica, and their functions
A
- lectin - mediates adherence
- amebapores - for penetration
- cysteine proteases - most important virulence factor, which produces ulceration with bleeding
15
Q
flask-shaped colon ulcers
A
Amebic colitis
16
Q
anchovy sauce-like aspirate
A
Amebic liver abscess
17
Q
Identify: most invasive among the Entamoeba genus.
A
Entamoeba histolytica
18
Q
These amebicides act on organisms in the bowel wall and the liver. Give examples
A
- Tissue amebicides
- chloroquine, emetines, metronidazole, tinidazole
19
Q
These amebicides act only in the lumen of the bowel. Give examples
A
-Luminal amebicides -diloxanide furoate, iodoquinol, paromomycin
20
Q
Drug of choice for asymptomatic luminal cysts of E. histolytica:
A
Diloxanide furoate
21
Q
Drug of choice for severe intestinal and extraintestinal amebiasis:
A
Metronidazole
22
Q
Pathologic effect of Giardia infection:
acute effects
chronic effects
A
- attach and causes pathologic changes to the intestinal villi (villous flattening, crypt hypertrophy, and disruption of cytoskeleton), causing malabsorption
- Acute infection: flatulence, abdominal pain, diarrhea
- Chronic infection: steatorrhea, constipation, weight loss
23
Q
Treatment of Giardiasis:
A
Metronidazole
24
Q
How is Giardia lamblia transmitted?
A
Ingestion of food/water from sources contaminated with feces containing cysts
25
Gold standard for diagnosis of Giardia lamblia
direct fluorescent antibody testing
26
This parasite cause Gay bowel syndrome. Why is this so?
Giardia lamblia - high prevalence in homosexuals due to to their oro-anal practices
27
* Manifestation of cryptosporidiosis
* Cryptosporidiosis is life-threatening in what condition: and why?
* self-limited non-bloody diarrhea
* CD4 \< 200, due to autoinfection
28
Treatment of cryptosporidiosis:
Usually self-limiting; DOC is Nitozoxanide, but in HIV patients, treatment with antiretrovirals may help the patient fight the pathogen on his own
29
Identidy: characterized by foul-smelling, greenish vaginal discharge, accompanied by itching and burning; with a characteristic strawberry cervix; What is the pathogen?
Trichomoniasis - cause by Trichomonas vaginalis
30
The only protozoal form of Trichomonas vaginalis
Trophozoite
31
How is trichomoniasis transmitted?
sexual intercourse (ping-pong transmission)
32
Treatment for trichomoniasis
Single dose 2 g oral metronidazole
33
most important parasitic disease in man
Plasmodium
34
What is the vector for Plasmodium?
Anopheles flavirostris minimus (infected female)
35
Two processes in the asexual life cycle of Plasmodium
* shizogony - occurs inside the RBCs
* gametogony
36
Process in the sexual life cycle of Plasmodium. Where does it occur?
sporogony - occurs inside the female mosquito (Anopheles flavirostris minimus)
37
What conditions are said to be protective against Plasmodium infection? (immune to malaria)
defects in RBC morphology (G6PD deficiency, sickle cell disease)
38
Term: recurrence of symptoms after a temporary abatement. Which Plasmodium species exhibit this?
- Recrudescence
- P. falciparum and P. malariae
39
* Term: return of a disease after its apparent cessation.
* Which Plasmodium species exhibit this?
* In Plasmodium, how does this happen?
* Relapse
* P. ovale and P. vivax
* due to reactivation of hypnozoites
40
Identify: Plasmodium: intermediate host / definitive host
humans / Anopheles flavirostris minimus
41
Gold standard for diagnosis of Plasmodium:
Giemsa stain:
1. Thick smear - to screen for presence of organisms
2. Thin smear - to identify the species of the infecting organism
42
* Identify: Punctate granulations present in red blood cells that contain hypnozoites.
* What Plasmodium species causes these changes?
* Schuffner dots
* Plasmodium ovale and Plasmodium vivax
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* Identify: coarse granulations present in red blood cells.
* What Plasmodium species causes these changes?
* Maurer dots
* Plasmodium falciparum
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* Identify: fine dots present in red blood cells.
* What Plasmodium species causes these changes?
* Ziemann dots
* Plasmodium malariae
Ziemann is a Fine Man
45
A severe complication of P. falciparum malaria, characterized by intravascular hemolysis, massive hemoglobinuria, and acute renal failure
blackwater fever
46
A severe form of malaria that is accompanied by septic shock.
Algid malaria
47
Enumerate: Usual symptoms of malaria (5)
* malaise
* joint pains
* hemolytic anemia
* jaundice
* splenomegaly
48
Term: These antimalarial drugs kill schizonts in the liver. Give some examples
- Tissue Schizonticides
- primaquine
49
Term: These antimalarial drugs kill the parasitic forms only in the RBCs. Give some examples
- Blood schizonticides
- chloroquine, quinine
50
Term: These antimalarial drugs kill gametocytes in human blood. Give some examples
- gametocides
- primaquine
51
Term: These antimalarial drugs prevent sporogony and multiplication in the mosquito. Give some examples
- sporonticides
- proguanil, pyrimethamine
52
Per Plasmodium species, in terms of erythrocyte age, what erythrocytes do they target? (young vs old)
* vivax - young RBCs
* ovale - young RBCs
* malariae - old RBCs
* falciparum - all ages
Vata, oVata, Matanda, Futa
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Form of heme that is non-toxic to the Plasmodium cell
Hemozoin
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* Definitive host of Toxoplasma gondii
* DOC
* domestic cat
* sulfadiazine and pyrimethamine
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How is Toxoplasma transmitted?
- ingestion of food/water with fecal oocysts
- transplacentally
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Two types of trophozoites of Toxoplasma
1. Tachyzoites - rapidly multiplying
2. Bradyzoites - slowly multiplying
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Enumerate: signs of Congenital toxoplasmosis
* hydrocephalus
* encephalitis
* chorioretinitis
* hepatosplenomegaly
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vector of Trypanosoma cruzi
reduviid (Triatoma) bug bite
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Tissue that is the most frequently and severely affected by T. cruzi
cardiac tissue
60
What is the Romana sign?
* periorbital edema in acute Chagas disease
61
What is a chagoma?
inflammatory nodule near the bite, in acute Chagas disease
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Enumerate: manifestations of chronic Chagas disease:
- myocarditis
- megacolon
- megasesophagus (achalasia)
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Treatment for Chagas disease
Nifurtimox
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Causative agent of West African sleeping sickness
Trypanosoma brucei gambiense
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Causative agent of East African sleeping sickness
Trypanosoma brucei rhodesiense
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Which is more rapid and fatal, gambian or rhodesian sleeping sickness?
Trypanosoma brucei rhodesiense
Rapid Rhodesian! Fatallll
67
* spectrum of disease caused by Trypanosoma brucei:
* indurated skin ulcer (trypanosomal chancre)
* enlargement of posterior cervical LN (winterbottom sign)
* hyperesthesia (Kerandel sign)
* encephalitis - Mott cells
* somnolence
68
DOC for advanced West African sleeping sickness
Eflornithine
WE - PESM
West / East
Pentamidine, Eflornithine / Suramin-Melarsoprol
It SUR is nice to sleep because of MELAtonin -\> Suramin-Melarsoprol
69
DOC for advanced East African sleeping sickness
Melarsoprol
WE - PESM
West / East
Pentamidine, Eflornithine / Suramin-Melarsoprol
It SUR is nice to sleep because of MELAtonin -\> Suramin-Melarsoprol
70
DOC for early West African sleeping sickness
Pentamidine
WE - PESM
West / East
Pentamidine, Eflornithine / Suramin-Melarsoprol
It SUR is nice to sleep because of MELAtonin -\> Suramin-Melarsoprol
71
DOC for early East African sleeping sickness
Suramin
WE - PESM
West / East
Pentamidine, Eflornithine / Suramin-Melarsoprol
It SUR is nice to sleep because of MELAtonin -\> Suramin-Melarsoprol
72
How is African sleeping sickness transmitted?
bite of the tsetse fly (Glossina)
73
Term: T. brucei is able to evade the immune response, causing cyclic fever spikes (every how long?) due to the ability to change its surface coat.
Antigenic variation
-every 2 weeks
74
Causative agent of: cutaneous Leishmaniasis
Leishmania tropica
**C**u**T**aneous - **T**ropi**C**a
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Causative agent of: visceral Leishmaniasis
Leishmania donovani
donoVani - Visceral
76
Another name for visceral Leishmaniasis
Kala-azar
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Causative agent of: mucocutaneous Leishmaniasis
Leishmania braziliensis
78
vector of Leishmania
sandfly (Phlebotomus)
79
Treatment for Leishmaniasis:
Stibulum gluconate
80
Enumerate: Free-living ameba
1. Acanthamoeba castellani
2. Naegleria fowleri
81
How is N. fowleri transmitted?
by swimming in contaminated pools/ponds
82
* Identify: the only ciliated protozoans to cause human disease.
* What disease do they cause?
* What is the morphology of the ulcer?
* Balantidium coli
* Balantidial dysentery
* round-based, wide-necked intestinal ulcers
83
How is Babesia microti transmitted?
bite of the Ixodes tick, typically while hunting or wandering in the woods
84
* morphology of Babesiosis
* Maltese cross - trophozoites in tetrads
85
Identify: the largest protozoan parasite
Balantidium coli
86
Gold standard for diagnosis of Babesiosis?
PCR
87
Enumerate: Two differential diagnoses for cryptosporidiosis
* Cyclospora cayatanensis
* Isospora belli
* they also cause diarrhea in immunocompromised patients
88
most common and largest intestinal nematode
Ascaris lumbricoides
89
Enumerate: soil-transmitted helminths
- Ascaris,
- Hookworms (Ancylostoma and Necator), and
- Trichuris
- Enterobius vermicularis
90
Enumerate: Parasites with transpulmonary stages
* Ascaris lumbricoides
* Ancylostoma duodenale (hookworm)
* Necator americanus (hookworm)
* Strongyloides stercoralis
91
enumerate: diagnostic tests for Ascaris lumbricoides (2)
- direct fecal smear
- Kato-katz technique
92
hypersensitivity pneumonitis (eosinophilia) caused by Ascaris lumbricoides in the lungs
Loeffler's syndrome
93
Enumerate: hookworms
- Necator americanus
- Ancylostoma duodenale
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Buccal organ of Necator americanus
cutting plate
ne**cat**or = **catting** plate
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Buccal organ of Ancylostoma duodenale
teeth
96
Identify: "new world hookworm"
Necator americanus
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Identify: "old world hookworm"
Ancylostoma duodenale
98
Diagnostic tests for hookworms:
Direct fecal smear
Katokatz technique
99
How much blood is being lost everyday to hookworms?
0.25 mL per worm per day
100
This substance produced by the hookworms aids in blood-sucking:
Anticoagulant
101
How are hookworms transmitted?
Hookworms penetrate throught the skin
102
Serpiginous tracts of hookworms are called:
cutaneous larva migrans
103
Common term for Trichuris trichiura:
whipworm
104
How to diagnose Trichuris?
Direct fecal smear
Katokatz technique
105
Morphology of Trichuris trichiura
barrel-shaped eggs with bipolar plugs
106
* Spectrum of disease in Trichuris infection
* diarrhea
* rectal prolapse - from increased peristalsis to expel the worms
107
Most common soil-transmitted helminth in developing countries:
Enterobius vermicularis
108
Identify: Enterobius vermicularis: intermediate host / definitive host
Its life cycle is confined to HUMANS ONLY
109
How to diagnose Enterobius vermicularis? What will you see?
Graham scotch tape techinique - D-shaped cells
110
Describe pathogenesis of Enterobius vermicularis:
Female worms release thousands of fertilized eggs on perianal skin, causing perianal pruritus -\> autoinfection
111
* spectrium of disease for enterobiasis:
* pruritus ani
* eosinophilic enterocolitis
* vulvovaginits
* appendicitis (Oxyuriasis)
112
Treatment for Enterobius vermicularis
Pyrantel palmoate
113
How is Strongyloides stercoralis transmitted?
The larvae penetrate the skin.
114
How to diagnose Strongyloides?
Harada-Mori culture
115
Infection of Strongyloides on immunicompromised patients results to
Hyperinfection
116
* Spectrum of disease in acute Strongyloides infection:
* ground itch
* diarrhea
* eosinophilic pneumonia
117
Term for serpiginous tract of Strongyloides stercoralis:
larva currens
118
Spectrum of disease in chronic Strongyloides infection:
* serpiginous tracts
* duodenitis
* paradoxical asthma
* hyperinfection syndrome
119
The only nematode whose life cycle involves a migratory bird:
Capillaria philippinensis
120
How is Capillaria philippinensis transmitted?
Eating undercooked fish
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* How to diagnose Capillaria philippinensis?
* morphology:
* Direct fecal smear
* Kato-katz technique
* peanut-shaped eggs with flattened bipolar plugs
122
Effects of acute infection of Capillaria?
* borboborygmus
* fever, abdominal pain, eosinophilia
123
Effects of chronic infection of Capillaria?
- severe malabsorption
- protein-losing enteropathy
- hypogammaglobulinemia
124
* Identify: this nematodes is able to cause the human host to have a "gurgling stomach".
* What is the term for this symptom?
* Capillaria philippinensis
* Borborygmus
125
Most debilitating nematode infection:
Filiariasis
126
Enumerate: two species of filarial worms
- Wuchererria bancrofti
- Brugia malayi
127
Usual scenario of filarial infection:
-Farmer from abaca plantation
128
* Which filarial worm is smoothly curved?
* kinky?
* Wuchereria
* Brugia
129
Which filarial worm is prevalent only in South East Asia?
Brugia
130
Mosquito vector of Wuchereria:
* Aedes
* Anopheles
* Culex
131
Mosquito vector of Brugia
Mansonia
132
Disease caused by Wuchereria:
Hydrocoele
133
Disease caused by Brugia:
Elephantiasis
134
Mechanism of transmission of filarial worms:
mosquito bite
135
A. Diagnosis of filarial worms:
B. When should blood samples be collected? Why?
A.
* Thick blood smear
* DEC provocation test, allows collection of blood specimens even at daytime
B. Between 8 PM and 4 AM - due to their nocturnal periodicity
136
Explain the pathogenesis caused by the filarial worms.
Adult worms cause inflammation in the lymph nodes and cause obstruction of the lymphatic vessels, causing lymphedema.
137
Morphology of granulomas seen in Filarial infection:
Meyers-Kouwenaar bodies
138
Manifestations of chronic filarial infection:
* hydrocoele
* elephantiasis
* chyluria
139
What parts of the Philippines experience Bancroftian filariasis?
Sorsogon, Samar, Leyte, Palawan
140
What parts of the Philippines experience Malayan filariasis?
Eastern Samar
141
DOC for filariasis:
diethycarbamazine
142
Identify: Trichinella spiralis: intermediate host / definitive host
pigs / humans
143
Mechanism of transmission of Trichinella:
consumption of undercooked pork
144
How to diagnose Trichinosis:
- muscle biopsy (**Nurse cells**)
- elevated creatine phosphokinase
- xenodiagnosis
145
Spectrum of disease in trichinosis:
* periorbital edema
* hemorrhagic phenomena (subconjunctival, splinter)
* respiratory myositis
146
DOC for trichinella
thiabendazole
147
Leading cause of blindness in sub-Saharan Africa (what organism?)
Onchocerca volvulus
148
Vector of Onchocerca volvulus:
female blackfly (Simulium)
149
Clinical finding in Onchocerciasis:
river blindess
150
What causes the Mazotti reaction?
inflammatory reaction to the lysis of the worms
151
- Enumerate the 3 trematodes
- Sites of affectation
- intermediate hosts
- Schistosoma japonicum / Paragonimus westermani / Chlonorchis sinensis
- Liver / lung / liver
- snail / snail and crab / snail and fish
152
How is paragonimiasis transmitted?
Consumption of raw crabs
153
Treatment of choice for trematodes:
Praziquantel
154
Common name for Schistosoma japonicum:
oriental blood fluke
155
Intermediate host of S. japonicum:
Oncomelania snails
156
How is schistosomiasis transmitted?
the cercariae penetrate the skin
157
Diagnostic tests for Schistosomiasis (and morphology)
- Katokatz techiniqe
- Circumoval precipitin test (ovoid egg with small hook - lateral knob)
158
Spectrum of disease in Schistosoma japonicum infection:
* swimmer's itch
* Katayama fever
* chronic liver disease
159
Areas of endimicity of S. japonicum:
Leyte, Samar, Sorsogon
160
Another name for Paragonimus westermani:
lung fluke
161
Intermediate hosts of Paragonimus westermani:
- snail (Antemelania asperata)
- mountain crab (Sundathelphusa philippina)
162
Diagnostic test for Paragonimus:
3% NaOH preparation
163
* Spectrum of disease in Paragonimiasis
* chest X-ray:
* chronic cough with bloody sputum (TB-like)
* ring-shadowed opacity
164
Two species of Asian Liver flukes:
- Clonorchis sinensis
- Opistorchis viverrini
165
Intermediate hosts of Clonorchis sinensis:
- snail (Parafossarulus)
- fish (Cyprinidae)
166
How is Clonorchis sinensis transmitted?
consumption of undercooked/raw fish
167
Diagnostic tests for Clonorchis sinensis:
morphology:
Direct fecal smear
Potassium permanganate stain (ovoid with melon-like ridges and abopercular protruberance)
168
Serious complication of chronic Clonorchis sinensis infection:
cholangiocarcinoma
169
diagnostic stage for Taenia:
gravid proglottid
170
* Cestode that can cause neurocysticercosis:
* Appearance on CT scan:
* Taenia solium
* ring-enhancing lesion
171
Manifestations of T. saginatta infestation:
pruritus ani and intestinal obstruction
172
DOC for Taenia solium
Praziquantel
173
DOC for Taenia saginata
Praziquantel
174
* also known as Fish tapeworm
* morphology:
* Diphyllobothrium latum
* sucking grooves and operculated eggs
175
how is Diphyllobothrium latum transmitted?
Consumption of undercooked fish
176
Hematologic effect of Diphyllobothrium latum infection:
megaloblastic anemia due to vitamin B12 deficiency (absorbed by the tapeworm)
177
DOC for Diphyllobothrium latum:
praziquantel
178
Identify: Echinococcus granulosus: intermediate host / definitive host
sheep or man / dogs
179
Diagnostic test for Diphyllobothrium latum:
- direct fecal smear
- Katokatz
180
What is the pathologic effect of hydatid cyst rupture:
severe anaphylaxis
181
* DOC for Echinococcus granulosis
* Treatment of choice in hydatid cysts
* Albendazole
* Surgical resection
