Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Block 5 > Parasitology > Flashcards

Parasitology Flashcards

1
Q

What is a definitive host for a parasite?

A

Host in which the sexual stage of a parasite life cycle occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is an intermediate host?

A

Host in which asexual reproduction or development occurs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is an incidental host?

A

A host that is not an obligate part of the parasite life cycle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a cysticercus?

A

Encysted cestode larval form in tissues of infected intermediate host

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the class cestoda of worms?

A

No internal digestive system, include tapeworms;

transmission by ingestion of larval cysticeri or eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the class Trematoda of worms?

A

Flukes of the lungs, liver and blood

broad flattened bodies witha simple digestive system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the intermediate host of Taenia solium?

A

Pigs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the pathology of taenia solium?

A

Taeniasis(adult worm in gut) often asymptomatic occasionally nausea, vomitting diahrrea weight loss
Cysitercosis ~1cm cysticeri located in any tissue causes
lumps and some inflammation neurocysticericosis is potentially dangerous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How is Taenia solium diagnosed?

A

Active proglottids in feces, or eggs

contrast studies

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is the treatment for Taenia solium?

A

Praziquantel, niclosamide or albendazole and dexamethasone is used to reduce inflammation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is dyphyllobothrium latum?

A

Fish tapeworm, similar to beef and pork versions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the pathology associated with dyphyllobrothorium latum?

A

Fish tapeworm, like beef tapeworm. Adults absorb 80-100% dietary B12 leading to B12 defficiency and anemia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is used to treat dyphyllobrothorium latum?

A

Praiquantel or niclosamide (single dose)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Echinococcosis?

A

Tapeworm in which dogs are definitive host and humans are incidental.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is the pathology associated with echinococcosis?

A

Hydatid cysts which can appear as tumors, Majority are in the liver and lungs
20 year latent period
disease can onset when it causes pain or ruptures

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the treatment of echinococcosis?

A

Percutaneous drainage with instillation of hypertonic saline or alcohol.
Surgical removal
Treat with albendazole but low cure rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are schistosomiasis?

A

Blood flukes, 3 major that effect humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What are the intermediate hosts of shistosomiasis? And how are they transmitted?

A

The intermediate host is snails.

Invasive, aquatic free-living cercaria penetrate skine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the morpohological differences between teh three schistosome eggs?

A

S. Mansoni have a lateral spike
S. haematobium have a terminal spike
S. Japonicum have no spike

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the pathology associated with schistosomiasis?

A

Early–no symptoms, possible rash, fever, headache, nausea as it migrates
Middle(onset 1-2 months)–from immune response to eggs
intense fever with oviposition, Katayama syndrome
abdominal pain, diarrhea, blood in stool
urogenital can cause blood in urine
Chronic (onset 5+ years)
eggs lodge in tissue
eosonic inflammation leading to granulomas
S. mansoni and S. japonicum go to severe liver disease and colon
S. haematobium go to extesnive fibrosis of bladder

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Where do the adult worms and eggs migrate to in each type of schistosomiasis?

A 
Adult worms located in:
S. mansoni--inferior mesenteric veins
S. Japonicum--superior mesenteric veins
S haematobium--venous plexus of bladder
eggs migrate to:
"-descending colon
"-small intestine
"-bladder
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the treatment for schistosomiasis?

A

Normally they are masked from immune system by absorption of host serum proteins
Praziquantel in either single or multiple doses potentiates active immunse system killing of adult worm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are the three different types of nematoda that act as parasites in humans/

A

lumenal[eneterobius vermicularis, trichuris trichiuria, ascaris lumbricoides]
hookworm[necator americanus, strongyloides stercoralis]
tissue worms[trichinell spiralis, toxocara canis]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is enterobius vermicularis?

A

Aka Pinworm

transmited by ingestion of eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What are some symptoms of enterobius vermicularis?

A

gravid female emerges from anus to lay eggs
perianal scratching facilitates transmission
perianal itch, restlessness, insomnia confirm by observation of eggs, scotch tape test

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the pathology associated with enterobius vermicularis?

A

Intesnse perianal pruritis
secondary infections due to scratching
urogenital invasion in female
no immunity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is the treatment for enterobius vernicularis?

A

pyrantel pamoate, mebendazole, albendazole along with thorough housecleaning

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is trichuris trichiura?

A

Whipworm, adults attach to colonic mucosa

definitive host is humans only

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the lifecycle of trichuris trichiura?

A

Eggs are swallowed, hatch in intestine, adults mate and migrate to colon, eggs mature in soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is the pathology of the trichuris trichiura?

A

Worm Burden:
low to moderate: usually none, bleeding, bacteremia
high: disrupted colonic mucosa, bloody stool, prolapse
heavy burden in children leads to impaired growth and impaired cognitive ability

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the treatment of trichuris trichiura?

A

3 days of ivermectin, mebendazole or albendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

What is ascaris lumbricoides?

A

Definitive host humans, ingestion of eggs from soil. no person to person

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What is the pathology of ascariasis lumbricoides?

A

Usually none with low to moderate worm bruden
heavy worm loads can lead to intestinal obstruction
stressed worms migration to other parts of body
chronic malnutrition
allergic inflammation from larval migration through lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What is the treatment for ascariasis lumbricoides?

A

MEbendazole, albendazole, ivermectin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What is necator americanus and ancylostoma duodenale?

A

Hookworm, with humans as a definitve host. Migrate to small intestine invasive contact through soil, no direct person to person contact

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

What is te life cycle of hookworm necator americanus?

A

Filariform larvae invade skin, go to circulation and lodge in lungs. Larvae coughed up and swalowed. Mature to adult in intestine, eggs to soil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the pathology associated with necator americanus?

A

Initial pruritis
bronchitis
exsanguination
anemia nd reduced mental and physical development in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What is strongyloides stercoralis?

A

Small intestine located parasites with humans as their definitive host. Filariform penetrate skin, autoinfection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What is the treatment for strongyloides stercoralis?

A

pyrantel pamoate, albendazole and mebendazole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What is unique about the strongyloides stercoralis life cycle?

A

3 alternative pathways
direct: like hookworm, but no eggs, larvae in feces
indirect: sexual replication in soil
Autoinfection: larvae mature in host, enter through colonic mucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

How is strongyloides stercoralis diagnosed?

A

Difficult because no eggs are excreted, iodine detection
fecal smear stianed with auramine O under UV light
Agar plate shows muiltile rhabditiform
Gram staining of a sputum can detect filariform
Serology sensitivity but lots of cross reactivity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

What is teh pathology associated with strongyloides stercoralis?

A

Pulomonary manifestations
chronic inestinal malabsorption and dysentery
rash
autoinfection and immunosuppression can lead to hyperinfection

43
Q

What is the treatment associated with strongyloides stercoralis?

A

ivermectin 1st choice, thiabenazole 2nd choice

44
Q

What is trichinella spiralis?

A

Found in intestine and larvae in muscle, aka trichinosis
definitve host is swine and bears
humans area dead end incidental host

45
Q

What is the pathology of trichinella spiralis?

A

Mild pathology from adult worms
localized inflammation around cysts adn degeneration of muscle
can have severe symptoms, cardiac adn nerual dysfunction, conjunctivitis, fever, muscle pain

46
Q

What is the treatment and diagnosis for trichinella spiralis?

A

Treatment is mebendazole or albendazole as wella s corticosteroids for symptoms
serological test three weeks or longer after infection

47
Q

What is toxocara canis?

A 
Definitive host dogs
incidental host dogs
tocoariasis
ingestion of embryonated eggs from soil
most dogs infected
48
Q

What is the the pathology of toxocara canis?

A

light infection; self-limiting pathology
heavy worm loads can lead to necrosis
enlarged liver, pulmonary complications neurological symptoms
immune hypersensitivity common

49
Q

What is the Leishmania life cycle?

A

Sandfly ingest macrophages infected, transform in promastigote, divides in midgut of sandfly, and transfers to human where phagocytosed in macrophage and transformes into amastigotes inside macrophage

50
Q

What is the pathology of cutaneous leshmaniasis?

A

Starts as bump, then an ulcerative sore, abundant amastigotes in lesions, spontaneous healing, strain-specific immunity
metastisis months to years after primary lesion heals, ulceration nasopharynx tissues
visceral leishmaniasis 2-12 months
fever adn wasting splenomegaly and hepatomegaly

51
Q

What is the life cycle of African trypanosomes (sleeping sickness)

A

Testes fly bites human, inject trypomastigotes which transform and multiply by binary fisssion in various body fluids, taken up in blood by tsetse fly, transform again in midgut of tsetse fly

52
Q

What is the pathology of african trypanosomiasis(sleeping sickness)?

A 
self healing chancre
hematogenous dissemination to lymphatics and tissues
waves of parasitemia with fever
lymphadenopathy (winterbottom's sign)
CNS infection, sleeping, dementia
death trhough coma or 2ndary infection
immune evasion by antigen variation
always fatal if untreated
53
Q

What are the treatments for trypanosomias?

A

First stage treatments: early on drugs are good
Pentamidine, Suramin
Second stage treatments( late they must cross blood brain barrier
melarsoprol
eflornithine and nifurtiox

54
Q

What is south american trypanosomiasis?

A

trypanosoma cruzi
vector borne by reduvid bugs
transfusion
endemic in South america

55
Q

What is the pathology of chagas disease, Trypanosomiasis?

A 
Acute 2-4 mos fever, chagoma (Romana's sign)
hematogenous spread
sever in children
chronic: onset at 10-20 yers
peristant amastigotes
damage to nerve/muscle cells of heart esophogaus
inflammation and autoimmunity
death from sudden heart attack
no Tx for chronic Chagas
56
Q

hat is trichomonas vaginalis?

A

luminal or urogenital, no free living or encysted state, stable 24 hours out,

57
Q

What is the pathology of Trichomoniasis?

A

not life threatening, 70% asymptomatic
vaginits, burning adn itching, inflammation, frothy vaginal discharge
male:
itching or irritation, burning after urination or ejaculation
increase risk of acquiring HIv

58
Q

What are the differences between fungi and higher eukaryotic cells?

A

contain ergosterol rather than cholesterol
antifungal drug amphotericin B binds it, and azole and allylamine interfere w/ biosynth
fungal cellsare usually surrounded by a rigid cell wall composed of carbohydrate polymers and proteins

59
Q

What are the two fungi that require interaciton with humans to live and are natural part of flora?

A

Candida albicans and Malassexia furfur

60
Q

What are two pathogenic yeasts?

A

Cryptococcus neoformans, and histoplasma capsulatum which is dimorphic

61
Q

What are the defining charactersitics of yeast?

A

unicellular, spherical or ellipsoid, reproduce by budding or fission

62
Q

What is hyphae/mycelium?

A

Also refured to as mold, hyphae is branching tubules, 3 types
mycelium is a mass of intertwine hyphae
Rhizoids , rootlike structures

63
Q

What are pathogenic molds?

A

Aspergillus which exists only as mold

candida albican which is dimorphic but mold morphotype is pathogenic

64
Q

What are condidiospores?

A

asexual reproductive elements taht can be borne naked on specialized structures, macroconidia large multicellular and micrcondia-small single celled

65
Q

What are sporangiospores?

A

Single celled spores that are formed within sacs called sporangea from the hyphae

66
Q

What are the problems from gneral funcal infections?

A

hypersensitivity, opportunistic infection mytotoxins

67
Q

What does Amanita cause when ingested?

A

severe or fatal liver and kiney damage inhibiting RNA polymerase 2

68
Q

What is produced by Aspergillus flavus taht causes what?

A

aflatoxin, mutagenic carcinogenic in contaminated grains

69
Q

What are some ways of diagnosing?

A

KOH-technique, direct microscopic exam, cultivation on blood agar, Serological methods, PCR, mass spec, FISH

70
Q

What are the targets of antifungal drugs?

A

ergosterol
cell wall syntehsis
nucleic acid synthesis
disruption of microtubules

71
Q

What are the four resistance mechanism to the azoles?

A

efflux pumps
decrease affinity of target enzyme for drug
increase expression of target enzyme
alternative metabolic pathway leading to ergosterol

72
Q

How does polyene cause resistance?

A

resistance to polyenes and amphotericin B is not common, mechansim of resistance is related to reduction of ergosterol in resistant organism or by masking it

73
Q

How does allyamines-terbinafine resistance occurs?

A

Clinical failure is not b/c of resistanc ebut due to CDR1 multidrug efflux pump

74
Q

HOw does echinocandins resistance occurs?

A

resistant organisms have point mutations in subunits of glucan syntehsis targets

75
Q

How does resistance to flucytosine occur?

A

alteration in permease that reduces uptake

alteration in enzymes necessary for conversion to active metabolites

76
Q

What type of helper t cells are important for immunocompetent individuals to clear fungal infections?

A

neutrophils, TH1 mediated resposne, humoral and cellular immunity
IL12 and IFNgamma

77
Q

What are the superficial mycoses?

A

Malassexia furfur
hortaea werneckii/exophiala werneckii
piedraia hortae
Trichosporon

78
Q

What are the cutaneous mycoses?

A

Dermatophytes:
Trichophyton
Epidermophyton
microsporum

79
Q

What are the subcutaneous mycoses?

A

sporothrix schenckii

80
Q

What is Malassezia furfur?

A

superficial, responsible for versicolor
lipophilic yeast, growth requires oil
small hypo or hyperpigmented macules that don’t tan
spontaneous resolution not likely, fluoreces

81
Q

What is hortaea werneckii

A

tinea nigra
dematiaceous frequenly branched septate hyphae
solitary irregular pigmented macule
can resemble malignant melinoma

82
Q

What is Piedraia hortae?

A

responsible for black piedra
brown to reddish-black mold
presence of dark nodules that surround hair shaft
cured witha hair cut

83
Q

What are the three endemic fungi pathogens?

A 
Histoplasma capsulatum(yeast))
Blastomyces dermatidis (yeast)
Coccidoides immitis (endospores)
they are dimorphic have different morphologies in environement as opposed to body mold in environemtn
can infect immunocompetend individuals
84
Q

How does infection occur most often from endemic environmentsal molds?

A

inhalation

85
Q

For endemic molds where is the usual primary infection and how else does it often present?

A

lungs, can disseminate and some poeple present with cutaneous lesions as a result of dissemination with blastomyces dermatidis

86
Q

What is the main diagnostic method?

A

microscopic ezamination

87
Q

Where are the endemic regions of each of hte endemic fungi?

A

cocci–>southwest
blastomyces midwest and ollowing the missippi and its tributaries
histoplasmosis–directly on mississippi

88
Q

Histoplasma capsultam is located where?

A

acidic soil, soil containing hig nirogen content, in those geographic regions 85% skin immunological activity indicating previous infection

89
Q

In host what is histoplasma capsulatum present as?

A

oval budding yeast with narrow bud head, insode mononuclear phagocytes and extracellular

90
Q

What is the hallmark of histoplasma capsulatum infection?

A

requries CD4+ T cells to control and produces granulomas containing phagocytes and lymphocytes to control fungal gowth
usually asymptomatic infection or flu like symptoms

91
Q

What are the clinical syndromes associated with histoplasma capsulatum?

A

pulmonary can resemble miliary tb on xray
acute pericarditis in 5% of symptomatic patients
disseminated in 1/2000 pts spread to blood
ocular histoplasmosis syndrome
fibrosing mediastinitis

92
Q

How does blastomyces appear in the body?

A

Large budding yeast witha large broad bud neck, 1/100000 in endemic areas

93
Q

How long is the incubation period for blastomyces?

A

4-6 weeks, trauma can lead to deep cutaneous infection

94
Q

What are the clinical syndromes of blastomyces?

A

Can present is a bening and self-limiting granulomatous
can present as TB like
has skin subcutaneous nodule or papule as most common extra pulmonary dissemination
can bind macrophage integrins

95
Q

Coccidoides present as what in humans?

A

Large spherules, that contain numerous small endosphores

96
Q

Coccidoides is usually acquired by what route?

A

respiratory route, after soild disrution in late summer and early fall, can have granulomatous infection

97
Q

What is the clinical syndrom of coccidoiides?

A

60 % asymptommatic, mild flu like syndrome 7-21 days after exposure
dissemination in 1% of cases can result in severe symptoms such as meningitis often fatal and dark skinned individuals are susceptible to disseminated disease
pregnancy a periilous time forinection
cocci most virulent fungal infection but 95% resolve iwthout therapy

98
Q

What is the role of cocci in AIDS patients?

A

25% develop it and third most common life threatening infection in AIDS pateints

99
Q

What are the mian treatments for endemic fungi?

A

in mild to moderate pulmonary diseae no treatment or itraconazole
in severe disseminated diseae Amphotericin B

100
Q

What are the most common causes of fungal infection pateint in hematopoietic stem cell and organ transplant pateints?

A

Candida and aspergillus

101
Q

What is the morphology associated with canddia?

A

complex morphology and yeast and hyphae morphologies are seen adn psuedohyphae, the pseudohyphae is the most frequently tissue invasive

102
Q

C. Albicans have what as virulence determinants?

A

invasive psuedohyphae
adhesion complex molecules, CR3 adn CR4 are targets and surfavce hyphal wall protein
hydrolytic enzyme

103
Q

Where are common sites for infection of opportunisitic myocytes?

A

skin, nail and mucosal can occr in immunocompetent bc of compromised local host
sites of surgical procedures and indwelling catheters
moist fat folds or abraded skin
broad spectrum antibiotics open up mucosal esp vagina to canidas

104
Q

Cryptococcus i swhat type of fungus?

A

monomorphic budding yeast
worldwide distribution
obreaks only observed in gattii

Block 5 (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions