Parasite2

Question 1

most important fatal helminth disease (250k people per year)

Answer 1

schistosomiasis

Question 2

what do people with schistosomiasis die from?

Answer 2

hepatic granulomas and fibrosis

Question 3

this parasite causes hematuria/obstruction of bladder, metaplasia in the bladder –> predisposes to squamous cell carcinoma

Answer 3

S haematobium

Question 4

cancer caused by metaplasia due to S haematobium infection

Answer 4

squamous cell carcinoma

Question 5

this form of schistosome infects humans by penetrating through skin (in between toes)

Answer 5

cercaria

Question 6

these cytokines cause induction of IgE synthesis, mastocytosis, and eosinophilia

Answer 6

IL 3, 4, 5

Question 7

resistance to reinfection of schistosome correlates with these levels

Answer 7

IgE

Question 8

fibrogenic factors secreted by lymphocytes that are induced by schistosome eggs

Answer 8

IL 13, TGF-B (FB proliferation and portal fibrosis)

Question 9

hallmark of schistosomiasis

Answer 9

hepatic fibrosis (out of proportion to parasite injury)

Question 10

results from *pipestream portal fibrosis* associated with schistosomiasis

Answer 10

portal hypertension, splenomegaly, esophageal varices, ascites

Question 11

aka liver flukes

Answer 11

Clonorchis siensis

Question 12

how do we get liver flukes? where do these live in body?

Answer 12

improperly cooked fish; biliary ducts

Question 13

possible complications of liver flukes

Answer 13

biliary hyperplasia, fibrosis, portal cirrhosis

Question 14

chronic infections of liver flukes

Answer 14

cholangitis, cholelithiasis, pancreatitis, cholangiocarcionma

Question 15

tapeworm from undercooked beef

Answer 15

Taenia saginata

Question 16

tapeworm from undercooked pork; what form of parasite does pork have in it?

Answer 16

Taenia solium; encysted cysticerci

Question 17

where do T solium encyst in hematogenous dissemination

Answer 17

CNS

Question 18

T solium infection characterized by cysts in CNS –> convulsions, increased pressure, mental disturbance

Answer 18

cysticercosis

Question 19

Echinococcus canine tapeworms that can form hydatid cysts (liver and lungs)

Answer 19

E granulosus and E multilocularis

Question 20

parasites that cause cysts

Answer 20

T solium and Echinococcus

Question 21

aka pinworm; most common parasite in USA, spread oral-fecal, *causes anal pruritis*

Answer 21

Enterobius vermicularis

Question 22

lifespan for pinworms (treatment prevents re-infection)

Answer 22

2 months

Question 23

pathogenesis of hookworms

Answer 23

small, itchy papule, pneumonitis, blood loss (.2 ml/worm/day)

Question 24

hyperinfections due to Strongyloides

Answer 24

pneumonitis and duodenitis

Question 25

symptoms/signs of Ascaris lumbricoides infection

Answer 25

pneumonitis, dyspnea, dry cough, fever, eosinophilia, colicky, malnutrition

Question 26

biggest complication/problem of Ascariasis

Answer 26

obstruction (of small intestine or biliary ducts)

Question 27

3 parasites that can penetrate muscle

Answer 27

Trichinella, Chagas, Echinococcus

Question 28

this causes symptoms associated with larval migrans syndromes

Answer 28

intense eosinophilic inflammatory reaction

Question 29

this causes cutaneous larval migrans

Answer 29

dog/cat hookworm (ancyclostoma)

Question 30

this causes visceral larval migrans

Answer 30

dog/cat ascaris (Toxocara canis, cati)

Question 31

this causes lymphatic filariasis

Answer 31

Wuchereria bancrofti

Question 32

scabies bites burrow into skin down to this layer

Answer 32

stratum corneum

Question 33

length of life cycle of scabies

Answer 33

28 days

Question 34

where do schistosomes replicate?

Answer 34

portal and pelvic venous systems

Question 35

tissue reaction to egg formation in schistosomiasis

Answer 35

granulomas and fibrosis

Question 36

these form around the schistosome egg

Answer 36

calcified pinhead granulomas

Question 37

this parasite is ingested, then the larvae hatch and penetrate thru the gut wall to encyst elsewhere in body

Answer 37

T solium

Question 38

symptoms associated with CNS encystment by T solium

Answer 38

convulsions, high intracranial pressure, mental disturbance

Question 39

hydatid cysts in Echinococcus infection most commonly form in these organs

Answer 39

liver and lungs

Question 40

this canine tapeworm causes liver disease that is almost always fatal

Answer 40

E multilocularis

Question 41

this canine tapeworm forms cysts that, when ruptured, can cause serious anaphylactic reaction

Answer 41

E granulosus

Question 42

this parasite is most common in moist areas of Southern US (tropics); can cause local hyperemia and lesions of colonic mucosa depending on worm load

Answer 42

whipworm (Trichuris trichiura)

Question 43

aka hookworms

Answer 43

Necator americanus (Southern US), Ancyclostoma duodenale (outside USA)

Question 44

where does hookworm attach?

Answer 44

small intestine

Question 45

dissemination route for Ascaris, Hookworms, and Stronyloides

Answer 45

ingest eggs/invade body - bloodstream - lungs - esophagus (from invasion filariform laravae) - GI

Question 46

how do hookworms get into body?

Answer 46

penetrate between toes

Question 47

this parasite has dissemination similar to hookworm; important reservoir in dogs and cats; may cause pneumonitis/dueodenitis in immunosuppressed

Answer 47

Strongyloides stercoralis

Question 48

these parasites penetrate skin to enter body

Answer 48

hookworm, strongyloides, schistosome

Question 49

most common parasite after pinworms (mostly in tropics/subtropics); HUGE, live in lumen of small intestine

Answer 49

Ascaris lumbricoides

Question 50

these parasites affect the small intestine

Answer 50

giardia, hookworm, strongyloides, ascaris

Question 51

how do you acquire Trichinella spiralis?

Answer 51

pork

Question 52

this parasite can penetrate tissue/encyst muscle; causes marked eosinophilia, fever, myalgias, periorbital edema --\> can also lead to hear failure due to myocarditis (from eosinophilia/giant cells)

Answer 52

Trichinella spiralis

Question 53

infiltrate in Trichinosis --\> can cause myocarditis in heart --\> scarring --\> heart failure

Answer 53

eosinophils and giant cells

Question 54

best treatment for larval migrans syndromes

Answer 54

corticosteroids and antihistamines

Question 55

these are signs/symptoms of visceral larval migrans

Answer 55

hepatomegaly, hypereosinophilia, hypergammaglobulinemia (hx of geophagia)

Question 56

this is responsible for neural larval migrans (from \*raccoons\*) --\> must diagnose parasite larvae present in tissues

Answer 56

Balisacaris

Question 57

neural laraval migrans (caused by Balisacaris) causes this severe CNS manifestation

Answer 57

eosinophilic meningoencephalitis

Question 58

this parasite develops within lymphatic channels --\> chronic damage w/ granulomas around adult parasite

Answer 58

Wuchereria bancrofti

Question 59

results from chronic damage associated with lymphatic filiarasis (Wuchereria bancrofti)

Answer 59

lymphatic dilation and lymphedema (elephantiasis in lower limb)

Question 60

this transmits Wuchereria bancrofti

Answer 60

mosquito

Question 61

this causes river blindness; what transmits it?

Answer 61

Onchocerca volvulus; black fly

Question 62

there is cross reaction between parasite antigen and these in Onchocerca volvulus infection --\> causes punctate keratitis and damage to retina

Answer 62

retinal pigment epithelial cells

Question 63

symptoms of river blindness (Onchocerca volvulus)

Answer 63

blindness, chronic pruritic dermatitis, subcu dermal nodules (onchocercoma)

Question 64

3 organisms that use head/body lice as vector to cause disease in humans

Answer 64

typhus, Rickettsia prowazeki; trench fever, Rochalimaea quintana; relapsing fever, Borrelia recurrentis

Question 65

these are symptomatic of Pthirus pubis infection (do not disappear w/ pressure, in deeper tissues)

Answer 65

Blue spots

Question 66

aka head/body lice

Answer 66

Pediculus humanus capitis/humanus

Question 67

responsible for scabies

Answer 67

Sarcoptes scabei

Question 68

this mediates scabies intense pruritic lesions

Answer 68

IgE, mast cells, eosinophils

Question 69

manifests as granulomatous of mucous membranes resulting in polyp formation --\> infection of nose, nasopharynx, and conjunctiva (traumatic inoculation from water source, especially in Texas/SW US)

Answer 69

Rhinosporidiosis