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Flashcards in FA - Micro - Parasitology Deck (138):
0

Giardiasis - Features?

1. Bloating
2. Flatulence
3. Foul-smelling
4. Fatty diarrhea (often seen in campers/hikers)

1

Giardiasis - Transmission?

Cysts in water.

2

Giardiasis - Diagnosis?

Trophozoites OR cysts in stool.

3

Giardiasis - Treatment?

Metronidazole.

4

Amebiasis - Features?

1. Bloody diarrhea (dysentery)
2. Liver abscess ("Anchovy paste" exudate)
3. RUQ pain (histology shows flask-shaped ulcer if submucosal abscess of colon ruptures).

5

Amebiasis - Transmission?

Cysts in water.

6

Amebiasis - Diagnosis?

Serology and/or trophozoites (with RBCs in the cytoplasm) OR cysts (with up to 4 nuclei) in stool.

7

Amebiasis - Treatment?

1. Metronidazole
2. Iodoquinol for asymptomatic CYST passers.

8

Cryptosporidium - Features?

Severe diarrhea in AIDS.
Mild disease (watery diarrhea) in immunocompetent.

9

Cryptosporidium - Transmission?

Oocysts in water.

10

Cryptosporidium - Diagnosis?

Oocysts on acid-fast stain.

11

Cryptosporidium treatment?

1. Prevention (by filtering city water supplies).
2. NITAZOXANIDE in immunocompetent hosts.

12

T.gondii - causes?

Reactivation in AIDS ==> Brain abscess seen as ring-enhancing brain lesions on MRI.

13

Congenital toxo - classical triad?

1. Chorioretinitis
2. Hydrocephalus
3. Intracranial calcifications

14

T.gondii - transmission?

1. Cysts in meat (MC).
2. Oocysts in cat feces.
3. Crosses placenta (pregnant women should avoid cats).

15

T.gondii - diagnosis?

Serology or biopsy (tachyzoites).

16

Toxo - Treatment?

Sulfadiazine + pyrimethamine.

17

Naegleria fowleri - causes?

Rapidly fatal meningoencephalitis.

18

N.fowleri - transmission?

1. Swimming in freshwater lakes .
2. Enters via cribriform plate.

19

N.fowleri - diagnosis?

Amoebas in spinal fluid.

20

N.fowleri treatment?

Amphotericin B has been effective for a few survivors.

21

T.brucei - causes?

African sleeping sickness.

22

African sleeping sickness - features?

1. Enlarged lymph nodes
2. Recurring fever (due to ANTIGENIC VARIATION)
3. Somnolence
4. Coma

23

T.brucei - Transmission?

Tsetse fly - a painful bite.

24

T.brucei - diagnosis?

TRYPOMASTIGOTE in blood smear.

25

T.brucei - Treatment?

1. Suramin ==> Blood-borne disease.
2. Melarsoprol ==> CNS penetration.

26

Malaria - Features?

1. Fever
2. Headache
3. Anemia
4. Splenomegaly

27

P.vivax/ovale - Features?

48h-cycle - tertian; includes fever on 1st day and 3rd day, thus fevers are actually 48h apart.

28

P.vivax/ovale - Dormant form?

Hypnozoites in liver.

29

P.falciparum - features?

1. Severe
2. Irregular fever patterns
3. Parasitized RBCs occlude capillaries in brain (cerebral malaria), kidney, lungs.

30

P.malariae - cycle?

72h - quartan.

31

Plasmodium - transmission?

Mosquito (Anopheles).

32

Plasmodium - diagnosis?

Blood smear:
1. Trophozoite ring form within RBC.
2. Schizont containing merozoites.

33

Plasmodium - treatment?

1. Begin with chloroquine, which blocks PLASMODIUM HEME POLYMERASE.
2. If resistant - use mefloquine or atovaquone/proguanil.

34

Plasmodium - Life-threatening - treatment?

1. IV quinidine (test for G6PD).
2. ARTESUNATE.

35

P.vivax/ovale treatment?

Add primaquine for hypnozoite (test for G6PD).

36

Babesiosis - features?

1. Fever
2. Hemolytic anemia

37

Babesiosis - where?

Predominantly in northeastern US.

38

Babesiosis - special risk?

Asplenia --> Incr. risk for severe disease.

39

Babesia - Transmission?

Ixodes tick (same as B.burgdorferi) - often coinfection.

40

Babesia - diagnosis?

1. Blood smear: Ring form - Maltese cross.
2. PCR.

41

Babesiosis - Treatment?

Atovaquone + Azithro

42

T.cruzi - causes?

Chagas

43

Chagas - features?

1. DCM + APICAL ATROPHY.
2. Megacolon
3. Megaesophagus

44

T.cruzi - where?

Predominantly in South America.

45

T.cruzi - transmission?

1. Reduviid bug - "kissing bug"
2. Feces
3. Deposited in a painless bite (much like a kiss)

46

T.cruzi - diagnosis?

TRYPOMASTIGOTE in blood smear.

47

T.cruzi - treatment?

1. Benznidazole
2. Nifurtimox

48

L.donovani - causes?

Visceral leishmaniasis (kala-azar).

49

Visceral leishmaniasis - features?

1. Spiking fevers
2. HSM
3. Pancytopenia

50

L.donovani - transmission?

Sand fly

51

L.donovani - diagnosis?

Macrophages containing AMASTIGOTES.

52

L.donovani - treatment?

1. Amphotericin B.
2. Sodium STIBOGLUCONATE.

53

T.vaginalis - causes?

Vaginitis.

54

T.vaginalis - not to be confused with?

G.vaginalis - gram variable bacterium associated with bacterial vaginosis.

55

T.vaginalis - Transmission?

Sexual (CANNOT EXIST OUTSIDE human because it cannot form cysts).

56

T.vaginalis - diagnosis?

Trophozoites (motile) on wet mount. "Strawberry cervix".

57

T.vaginalis - treatment?

Metronidazole for patient and partner (prophylaxis).

58

Enterobius vermicularis (pinworm) - transmission?

Fecal-oral

59

E.vermicularis (pinworm) - causes?

Intestinal infection causing ANAL PRURITUS (diagnosed via SCOTCH TAPE TEST).

60

E.vermicularis (pinworm) - treatment?

Bendazoles (because worms are bendy).

61

Ascaris lumbricoides (giant roundworm) - transmission?

Fecal-oral ==> eggs visible in feces under microscope.

62

Ascaris lumbricoides (giant roundworm) - disease?

Intestinal infection ==> Possible OBSTRUCTION at ileocecal valve.

63

Ascaris lumbricoides (giant roundworm) - treatment?

Bendazoles.

64

Strongyloides stercoralis - transmission?

Larvae in soil penetrate the skin.

65

Strongyloides stercoralis - disease?

Intestinal infection causing:
1. Vomiting
2. Diarrhea
3. Epigastric pain (may be peptic ulcer-like)

66

Strongyloides stercoralis - treatment?

Ivermectin or bendazoles.

67

Ancylostoma duodenale, Necator americanus (hookworms) - transmission?

Larvae penetrate skin.

68

Ancylostoma duodenale, Necator americanus (hookworms) - disease?

Intestinal infection causing:
Anemia --> Sucking blood from intestinal walls.

69

Ancylostoma duodenale, Necator americanus (hookworms) - treatment?

Bendazoles or pyrantel pamoate.

70

Onchocerca volvulus - transmission?

Female blackfly bite.

71

Onchocerca volvulus - Disease?

1. Skin changes.
2. Loss of ELASTIC FIBERS.
3. River blindness.
==> Black flies + Black skin nodules + Black sight.
==> ALLERGIC REACTION TO MICROFILARIA possible.

72

Onchocerca volvulus - treatment?

Ivermectin (IVERmectin for rIVER blindness).

73

Loa loa - transmission?

1. Deer fly.
2. Horse fly.
3. Mango fly.

74

Loa loa - disease?

1. Swelling in skin.
2. Worm in conjunctiva.

75

Loa loa - treatment?

Diethylcarbamazine.

76

Wuchereria bancrofti - transmission?

Female mosquito

77

Wuchereria bancrofti - disease?

Elephantiasis:
Worms invade lymph nodes and cause inflammation ==> Can block the lymphatic vessels.
==> Takes 9 MONTHS-1 YEAR after bite to become symptomatic.

78

Wuchereria bancrofti - treatment?

Diethylcarbamazine.

79

Toxocara canis - transmission?

Fecal-oral

80

Toxocara canis - disease?

Visceral larva migrans.

81

Toxocara canis - treatment?

Bendazoles.

82

Nemotodes (roundworms):

A. INTESTINAL:
1. E.vermicularis
2. Ascaris lumbricoides
3. Strongyloides stercoralis
4. Ancylostoma duodenale, Necator americanus
5. Trichinella spiralis.

B. TISSUE:
1. Onchocerca volvulus
2. Loa loa
3. Wucheria bancrofti
4. Toxocara canis

83

Nematode routes of infection - ingested?

1. Enterobius
2. Ascaris
3. Toxocara
4. Trichinella.

84

Nematode route of infection - Cutaneous?

1. Strongyloides
2. Ancylostoma
3. Necator

85

Nematode routes of infection - Bites?

1. Loa loa
2. Onchocerca volvulus
3. Wuchereria bancrofti

86

Cestodes?

1. Taenia solium
2. Diphyllobothrium latum
3. Echinococcus granulosus

87

Taenia solium - transmission?

1. Ingestion of larvae encysted in undercooked pork ==> Intestinal tapeworm.
2. Ingestion of eggs contaminated with human feces ==> Cysticercosis, neurocysticercosis.

88

Taenia solium - disease?

1. Intestinal tapeworm
2. Cysticercosis, neurocysticercosis

89

Taenia solium - intestinal infection treatment?

Praziquantel.

90

Taenia solium - cysticercosis, neurocysticercosis treatment?

1. Praziquantel
2. Albendazole for neurocysticercosis

91

Diphyllobothrium latum - transmission?

Ingestion of larvae from raw freshwater fish.

92

Diphyllobothrium latum - disease?

VitB12 def. (tapeworm competes for B12 in intestine) --> MEGALOBLASTIC Anemia.

93

Diphyllobothrium latum - treatment?

Praziquantel.

94

Echinococcus granulosus - transmission?

Ingestion of eggs from dog feces.
==> SHEEP are INTERMEDIATE HOST.

95

Echinococcus granulosus - disease?

Hydatid cysts in liver --> causing anaphylaxis if antigens released (surgeons preinject with ETHANOL or HYPERTONIC SALINE to kill cysts before removal).

96

Echinococcus granulosus - treatment?

Albendazole.

97

Trematodes (flukes) ?

1. Schistosoma
2. Clonorchis sinensis

98

Schistosoma -transmission?

Snails are host - cercariae penetrate skin of humans.

99

Schistosoma - disease?

1. Liver and spleen ENLARGEMENT, fibrosis, inflammation.
2. Chronic infection with S.haematobium can lead to SCC of the bladder (painless hematuria) + PULMONARY HTN.

100

Schistosoma - treatment?

Praziquantel

101

Clonorchis sinensis - transmission?

Undercooked fish

102

Clonorchis sinensis - disease?

1. Biliary tract inflammation --> pigmented gallstones.
2. Associated with cholangiocarcinoma!

103

Clonorchis sinensis treatment?

Praziquantel.

104

Biliary tract disease
Cholangiocarcinoma

Clonorchis sinensis

105

Brain cysts
Seizures

Taenia solium (NEUROcysticercosis)

106

Hematuria
Bladder SCC

Schistosoma haematobium

107

Liver (hydatid) cysts

Echinococcus granulosus

108

Microcytic anemia

Ancylostoma, Necator

109

Perianal pruritus

Enterobius

110

Portal HTN

Schistosoma mansonii, Schistosoma japonicum

111

VitB12 def

Diphyllobothrium latum.

112

2 Ectoparasites:

1. Scabies (Sarcoptes scabiei).
2. Lice (Pediculus humanus/Phthirus pubis).

113

Scabies (Sarcoptes scabiei) - Mites that ...?

1. Burrow into the STRATUM CORNEUM ==> Cause PRURITUS.
2. Causes serpiginous burrows (lines) in webspace of hands and feet.

114

Scabies (Sarcoptes scabiei) - Common in ...?

1. Children.
2. Crowded populations (jails, nursing homes).

115

Scabies (Sarcoptes scabiei) - Transmission through ...?

Fomites.

116

Scabies (Sarcoptes scabiei) - Tx:

1. Permethrin cream.
2. Washing/drying ALL CLOTHING/BEDDING.
3. Treat close contacts.

117

Lice (Pediculus humanus/Phthirus pubis):

BLOOD-SUCKING insects that prefer to live on CLOTHING.

118

Lice (Pediculus humanus/Phthirus pubis) - Cause ...?

1. INTENSE PRURITUS.
2. Pink macules + Papules commonly in intertriginous regions.

119

Lice (Pediculus humanus/Phthirus pubis) - Can transmit:

1. Rickettsia prowazekii (typhus).
2. Borrelia recurrentis (relapsing fever).
3. Bartonella quintana (trench fever).

120

Lice (Pediculus humanus/Phthirus pubis) - Tx:

1. Pyrethroids.
2. Malathion.
3. Ivermectin lotion.
4. Nit combing.

121

Children with head lice can be treated at ...?

HOME without interrupting school.

122

Myalgias + Periorbital edema:

T.spiralis.

123

Schistosoma mansonii - Morphology:

Egg with LATERAL SPINE.

124

S.haematobium - Morphology:

Egg with TERMINAL SPINE.

125

VISCERAL larva migrans (Toxocara canis) - Pathogenesis:

1. Nematodes migrate to BLOOD through intestinal wall causing inflammation and damage.
2. Organs frequently affected include:
A. HEART (myocarditis).
B. LIVER.
C. CNS (Seizures + coma).

126

Trichinella spiralis - Disease:

Intestinal infection.
==> Larvae enter bloodstream and encyst in STRIATED muscle ==> Inflammation of muscle.

127

Trichinosis:

1. Fever.
2. Vomiting.
3. Nausea.
4. Periorbital edema.
5. Myalgia.

128

T.spiralis - Transmission:

Fecal-oral ==> Undercooked meat (ESPECIALLY PORK).

129

T.spiralis - Tx:

Bendazoles.

130

Immune response to helminths:

Eosinophils act by HSR I + HRS II in responding to helminths.

131

Immune response to helminths - HSR I:

Neutralization of histamine and LTs.

132

Immune response to helminths - HSR II:

Eosinophils attach to surface of helminths via IgE + Release cytotoxins (eg MAJOR BASIC PROTEIN) contained in their granules.

133

Vaginitis:

1. Foul-smelling + Greenish discharge.
2. Itching + Burning.

134

Cutaneous leishmaniasis:

SKIN ULCERS.

135

T.cruzi - Characteristic of acute stage:

ROMANA SIGN ==> Unilateral periorbital swelling.

136

Malaria - Diagnosis of P.vivax/ovale?

Red granules (SCHUFFNER STIPPLING) throughout RBC cytoplasm seen with P.vivax/ovale.

137

2 subspecies of T.brucei:

1. Trypanosoma brucei rhodesiense.
2. Trypanosoma brucei gambiense.