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Flashcards in Protozoal infections Deck (112):
1

protozoa causing bloody diarrhea

- Entamoeba
- Balantidium

2

symptoms caused by entamoeba histolytic

- bloody diarrhea
- ulcers
- liver abscesses

3

epidemiology of entamoeba

- associated with camping/hikers
- fecal oral transmission - cysts are passed in stool

4

lifecycle of entamoeba

- only cyst form is infectious
- ingest cyst, stomach acid erodes cyst leading to growth and invasion
- trophozoites are the actively replicating form and indicates parasitic infection

5

pathogenesis of entamoeba

- gastric acid stimulates excystation
- local necrosis of large intestine
- destruction of epithelial cells

6

clinical disease of entamoeba

- ab pain and cramps, colitis, bloody diarrhea
- weight loss and anorexia
- liver abscess - flask shaped ulcer, fever, RUQ pain, tenderness

7

treatment of entamoeba

- non-invasive: paramomycin
- invasive: metronidazole followed by paramomycin

8

MOA of metronidazole

- destabilizes DNA

9

epidemiology of balantidium coli

- ciliate: only spp that infects humans
- fecal oral transmission
- pigs are reservoirs
- infection from ingested cysts

10

clinical disease of balantidium coli

- watery diarrhea WITH blood and pus
- ab pain, nausea, anorexia
- secondary bacterial infections of GI mucosa

11

treatment for balantidium coli

- tetracycline
- metronidazole and iodoquinol are alternatives

12

epidemiology of giardia

- fecal oral via cysts
- beavers and muskrats are reservoirs
- more common in campers and hikers and also in daycares
- most often transmitted from contaminated water

13

clinical disease of giardia

- explosive watery diarrhea
- foul smelling stools
- ab cramps
- can progress to malabsorption syndrome - steatorrhea (foul smelling (malodorous), mushy, greasy stool)

14

diagnosis of giardia

- microscopic examination of stool
- bilobed nuclei, looks like a horseshoe crab
- has flagellum
- falling leaf motility

15

treatment and prevention of giardia

- treat with metronidazole
- boil water and treat carriers
- cysts can survive in chlorinated water

16

epidemiology of cryptosporidium

- mainly affects children (peak age around 5)
- can be severe in IC patients - lethal in AIDS, #1 cause of AIDS associated diarrhea

17

pathogenesis of cryptosporidium

- oocyst is infectious form
- stains acid fast
- resistant to chlorination
- water born disease

18

lifecycle of cryptosporidium

- infects intestinal epithelial cells
- oocyst is infectious and diagnostic form

19

clinical disease of cryptosporidium

- asymptomatic to severe disease
- self limited (1-2 wk) enterocolitis
- watery diarrhea, dehydration, weight loss, ab pain, fever, N/V

- in AIDS pts, can shit up to 50 times a day

20

diagnosis of cryptosporidium

- acid fast staining
- pink is positive and green is negative

21

treatment of cryptosporidium

- replace fluids and electrolytes
- nitazoxanide for immunoCOMPETENT patients
- HAART therapy for AIDS patients

22

epidemiology of isospora belli

- humans are only known reservoir
- more prevalent in AIDS pts
- outbreaks are commonly seen in day cares and mental institutions
- fecal oral: mature oocysts ingested and reside in epithelium

23

clinical disease of isospora belli

- mimics giardiasis with malabsorption syndrome
- steatorrhea

24

diagnosis of isospora belli

- oocyst found in feces is elliptical
- cryptosporidium is round
- microscopic examination of iodine-stained stool smears

25

triad for isospora belli diagnosis

- acid fast staining
- malabsorption
- watery diarrhea

26

treatment for isospora belli

- TMP-SMX

27

characteristics of cyclospora cayetanensis

- resembles cryptosporidium excepts infects immunoCOMPETENT patients
- explosive watery diarrhea
- fecal contaminated water or food (raspberries or basil)

28

clinical disease of cyclospora cayetanensis

- low grade fever, fatigue, anorexia, abdominal pain, N/V

29

diagnosis of cyclospora cayetanensis

- stains acid-fast
- fluoresces blue under UV light

30

treatment of cyclospora cayetanensis

- TMP-SMX

31

latin name for pinworms

- enterobius vermicularis

32

common name for enterobius vermicularis

- pinworm

33

transmission of enterobius vermicularis (pinworm)

- fecal oral
- eggs are "sticky"
- eggs can be transmitted on fomites
- autoinfection occurs
- common in children 5-9 years old

34

clinical disease of enterobius vermicularis (pinworm)

- intense perianal itching at night
- prickling pain
- diarrhea during acute infection
- migrating worms may get lost: vaginal itching and granuloma formation

35

diagnosis of enterobius vermicularis (pinworm)

- cellophane (scotch) tape method
- only used for this type of worm

36

treatment for enterobius vermicularis (pinworm)

- mebendazole

37

latin name for roundworms

- ascaris lumbricoides

38

common name for ascaris lumbricoides

- roundworm

39

transmission of ascaris lumbricoides (roundworm)

- fecal oral
- contaminated food or water
- eggs can survive for months

40

lifecycle of ascaris lumbricoides (roundworm)

- ingest egg
- egg hatches and travels to liver, heart, lungs, etc.

41

clinical disease for ascaris lumbricoides (roundworm)

- dependent on number of eggs
- few eggs - asymptomatic
- early phase: large migrate to lungs producing fever, nonproductive cough, dyspnea, wheezing
- late phase: diffuse or epigastric pain, N/V, bolus can obstruct and perforate bowel

- can be lethal

42

diagnosis of ascaris lumbricoides (roundworm)

- CBC may show eosinophilia
- sputum may show larvae
- eggs in stool: knobby coated, oval shaped, bile stained

43

treatment for ascaris lumbricoides (roundworm)

- albendazole
- if pregnant then use pyrantel pamoate

44

toxocariasis (roundworm)

- dog and cat roundworms

45

symptoms of toxocariasis (roundworm)

- larvae can penetrate any tissue: lungs, heart, liver, kidney, skeletal muscle, eyes, CNS is most common
- bleeding, necrosis, eosinophilic granulomas

46

diagnosis of toxocariasis

- eggs found in pet feces
- eggs NOT found in human feces

47

treatment for toxocariasis

- albendazole

48

latin name for whipworm

- trichuris trichiura

49

- transmission of trichuris trichiura (whipworm)

- fecal oral
- prevalent in southern appalachian range and gulf coast states

50

clinical disease of trichuris trichiura (whipworm)

- light infections (100): ab pain, vomiting, anorexia, weight loss, diarrhea (can be bloody), tenesmus, rectal prolapse

51

diagnosis of trichuris trichiura

- barrel (football) shaped eggs, plugged ends
- RBC and WBC present

52

treatment of trichuris trichiura

- albendazole

53

latin name for hookworms

- ancylostoma duodenale
- necator americanus

54

epidemiology of hookworms (N. americanus)

- penetrate into feet
- go to lymphatics, blood, heart, lungs, cough them up and then swallow into GI tract

55

early symptoms of hookworms (N. americanus)

- itching, localized maculopapular eruption on foot
- low grade fever
- mild cough, wheezing when worm in lungs

56

late symptoms of hookworms (N. americanus)

- N/V, diarrhea
- microcytic and hypochromic anemia
- fatigue and dyspnea

57

chronic disease of hookworms (N. americanus)

- emaciation, physical and mental retardation

58

diagnosis of hookworms (N. americanus)

- early infection: eosinophilia, normal stool
- patchy infiltrate on chest X-ray (migrating larvae)

- GI infection: non-bile stained, segmented eggs in stool
- iron deficiency anemia

59

treatment of hookworms

- abdendazole
- iron therapy for anemia

60

anclyostoma braziliense (hookworm)

- dog and cat hookworm
- humans are accidental hosts

61

clinical disease of anclyostoma braziliense

- cutaneous larval migrans: ground itch, creeping eruption
- Loeffler syndrome: pulmonary infiltrates with peripheral eosinophilia

- at risk: children (sandboxes), beaches

62

treatment for anclyostoma braziliense

- thiabendazole

63

worm infections where humans are accidental hosts

- toxocariasis: dog and cat roundworms
- anclyostoma brazilense: dog and cat hookworm

64

latin name for threadworm

- strongyloides stercoralis

65

common name for strongyloides stercoralis

- threadworm

66

clinical disease of strongyloides stercoralis (threadworm)

- pneumonitis similar to hookworm
- occur in IC patients
- diarrhea can be bloody, malabsorption
- symptoms like peptic ulcer, peripheral eosinophilia

67

chronic infection of strongyloides stercoralis (threadworm)

- hyperinfection syndrome: profound diarrhea, malabsorption, electrolyte imbalance, meningitis, secondary bacteremia

- seen in IC patients

68

diagnosis of strongyloides stercoralis (threadworm)

- Baermann funnel gauze method

69

treatment of strongyloies stercoralis (threadworm)

- ivermectin

70

reservoir of trichinella spiralis

- pork, undercooked bear meat

- larvae form found in striated muscle

71

clinical disease of trichinella spiralis

- acute stage: larvae invade tissue: fever, diffuse myalgias, eosinophilia, periorbital edema

- late stage: lethal when heart, brain and lungs infected

72

diagnosis of trichinella spiralis

- outbreak traced to infected pork or beat meat
- encysted larvae in meat or muscle biopsy
- pt presents with diffuse muscle pain- diffuse myalgias
- CBC - marked eosinophilia

73

treatment of trichinella spiralis

- albendazole

74

transmission of anisakis simplex

- roundworm of marine fish
- higher incidence where raw fish is eaten

75

clinical disease of anisakis simplex

- within hours after ingested of undercooked (raw) fish
- violent ab pain, N/V
- severe eosinophilic granulomatous response if larvae pass into bowel
- can mimic Crohns

76

hosts for all flukes

- all flukes have clam or snail intermediate hosts

77

characteristics of fluke eggs

- all flukes (and tapeworms) have operculated eggs

78

latin name for giant intestinal fluke

- fasciolopsis buski

79

common name for fasciolopsis buski

- giant intestinal fluke

80

epidemiology of giant intestinal fluke

- ingestion of contaminated water chestnuts
- look like leeches or tiny tadpoles
- travelers from china, vietnam, thailand, india, malaysia

81

clinical disease of giant intestinal fluke (fasciolopsis buski)

- diarrhea alternating with constipation
- malabsorption syndrome with malodorous, greasy stools

82

diagnosis of giant intestinal fluke

- large, bile stained, operculated eggs in stool

83

treatment of giant intestinal flukes (fasciolopsis buski)

- praziquantel

84

latin name for sheep liver fluke

- fasciola hepatica

85

transmission of sheep liver fluke

- infection from contaminated water plants

86

clinical disease of sheep liver fluke (fasciola hepatica)

- URQ pain, fever, chills, eosinophilia, hepatitis, biliary obstruction

87

treatment of fasciola hepatica

- bithionol

88

latin name for chinese liver fluke

- clonorchis sinensis

89

transmission of chinese liver fluke

- consumption of undercooked freshwater fish

90

clinical disease of clonorchis sinensis

- fever, diarrhea, epigastric pain, hepatomegaly, anorexia, jaundice

91

treatment of clonorchis sinensis

- praziquantel

92

3 main species of schistosomes

- Schistosoma haematobium (bladder): terminal spine
- S. japonicum (bowel)
- S. manosin (bowel): lateral spine

93

transmission of schistosomes

- penetrate skin when swimming, burrow in and cause itching (swimmers itch)

94

clinical disease of schistosomes

- acute (Katayama syndrome): swimmers itch, fever, chills, cough, urticaria, ab pain, diarrhea, eosinophilia

- chronic: granulomatous reactions and fibrosis, bloody diarrhea (S. mansoni mostly), associated with clay pipestem fibrosis around portal vein

95

diagnosis of schistosomes

- leukocytosis, eosinophilia, polyclonal gammopathy
- S. mansoni: egg larva is oval shape and curved anterior end with lateral spine, found in stool
- S. japonicum: smallest eggs, oval shaped, spine not distint, found in stool
- S. haematobium: terminal spine, large egg, found in urine

96

treatment of schistosomes

- praziquantel

97

general characteristics of cestodes (tapeworms)

- flat and ribbon like
- head has cup shaped suckers and hooks
- segmented bodies: proglottids
- eggs in feces are diagnostic
- all eggs are operculated

98

epidemiology, transmission, and clinical disease of Taenia solium (pork tapeworm)

- undercooked pork
- in larvae ingested in meat: mostly GI symptoms - ab discomfort, diarrhea, indigestion
- cystericercosis is dangerous - eggs ingested in contaminated water, vegetables

99

diagnosis of taenia solium

- proglottids and eggs in feces

100

- treatment of taenia solium

- praziquantel

101

symptoms of neurocystericercosis

- hydroencephalitis, mengitis, nerve damage, seizures, visual defects

102

diagnosis of neurocystericercosis

- imaging studies for calcified cysticeri
- (CT,MRI) - big calcified cysts seen on MRI

103

treatment for neurocystericercosis

- praziquantel, albendazole
- steroids, surgery

104

latin name for beef tapeworm

- taenia saginata
- does not cause neurocystericercosis in humans
- diagnosis and treatment identical to T. solium infection

105

latin name for fish tapeworm

- diphyllobothrium latum

106

transmission and reservoir of fish tapeworms

- undercooked freshwater fish
- wild animal reservoirs: bears, minks, walruses, canine

107

clinical disease of fish tapeworms

- most are asymptomatic
- associated with depleted serum vitamin B12
- megaloblastic anemia, neurological manifestations: painful tingling, fatigue, weakness, loss of coordination, confusion, weight loss

108

treatment of fish tapeworm

- niclosamide
- praziquantel alternative
- vitamin B12 supplementation

109

Echinococcus spp.

- tapeworms of carnivores in sheep-raising areas
- humans are intermediate hosts

110

clinical disease of echinococcus spp.

- hydatid cyst disease
- liver and lung where cysts develop: ab pain, hepatic mass, bile duct obstruction
- lungs: chest pain, cough, hemoptysis

- death from anaphylactic shock after rupture of cysts

111

diagnosis of echinococcus spp.

- CBC- eosinophilia
- X-rays for cysts in lungs, bone and muscle

112

treatment for echinococus

- surgery
- albendazole and mebendazole are DOCs