Lymphatic Filariasis Flashcards

1
Q

is one of the most debilitating diseases in tropical countries

A

Lymphatic filariasis

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2
Q

Second leading cause of permanent and long-term disability, affecting both physical and psychological aspects (next to psychiatric illness)

A

Lymphatic filariasis

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3
Q

Infective Stage

A

• Third stage larvae

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4
Q

Diagnostic Stage

A

• Microfilariae

• Adult worm

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5
Q

Two most common mosquito-borne causative agents

A

Wuchereria bancrofti
Brugia malayi

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6
Q

Wuchereria bancrofti

• Common name:

• Causing (disease)

A

Bancroft’s filarial worm

Bancroftian filariasis

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7
Q

Brugia malayi

• Common name:

• Causing (disease)

A

Malayan filarial worm

Malayan filariasis

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8
Q

Epidemiology

• Cosmopolitan parasitic infection

•_____ people affected worldwide,____ endemic countties

A

120M

83

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9
Q

Epidemiology

•______ affects 90% of cases

•______ affect 10%

A

Wuchereria bancrofti

Brugia spp

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10
Q

Biology: Adult

Morphology

A

• Creamy white, long, filiform in shape

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11
Q

Adult

Found tightly coiled in nodular dilated nests (______) in lymph vessels and sinuses of lymph glands

A

lymphangiectasis

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12
Q

• Minute, snake-like organisms constantly moving among RBC

• Several curvatures and graceful appearance

A

Microfilaria

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13
Q

Microfilaria

Enclosed in______ that is longer than the microfilaria

________Important to species identification

A

hyaline sheath

• Dark-staining nuclei

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14
Q

Kinky with secondary curves

A

Brugia

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15
Q

Smoothly Curved

A

Wuchereria

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16
Q

Terminal Nuclei of Wuchereria

A

Absent

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17
Q

Terminal Nuclei of Brugia

A

Present

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18
Q

Prevalence of Wuchereria

A

Widespread

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19
Q

Prevalence of Brugia

A

Southeast Asia only

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20
Q

Mosquito Vector of Wuchereria

A

Aedes
Anopheles
Culex

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21
Q

Mosquito Vector Brugia

A

Mansonia

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22
Q

Preference of Wuchereria

A

Scrotal lymphatics

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23
Q

Preference of Brugia

A

Limb lymphatics

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24
Q

Clinical Picture of Wuchereria

A

Hydrocele

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25
Q

Clinical Picture of Brugia

A

Elephantiasis

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26
Q

Severity

Wuchereria
Brugia

A

More severe
Less severe

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27
Q

Cephalic Space length to width ratio

Wuchereria
Brugia

A

Wuchereria 1:1
Brugia 2:1

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28
Q

Stylet at anterior end

Wuchereria
Brugia

A

Wuchereria - Single
Brugia - Double

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29
Q

Excretory Pore

Wuchereria
Brugia

A

Wuchereria - Not prominent
Brugia - Prominent

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30
Q

Nuclei column

Wuchereria
Brugia

A

Wuchereria - large course discrete
Brugia - overlapping blurred

31
Q

Tail

Wuchereria
Brugia

A

Wuchereria - pointed and free of nuclei
Brugia - pointed with 2 distinct nuclei

32
Q

Sheath

Wuchereria
Brugia

A

Wuchereria - faintly stained
Brugia - well stained

33
Q

Pre larval form of filariasis

A

Microfilaria

34
Q

Mosquito takes
a blood meal

A

L3 larvae enters skin or
Mosquito ingests Microfilariae

35
Q

Adults in

A

lymphatics

36
Q

Adults produce sheathe microfilariae that migrate into

A

lymph and blood channels

37
Q

Microfilariae shed sheaths.
pentrate mosquito’s____,
and migrate to____ muscles

A

midgut

thoracic

38
Q

Inf stage to humans

A

Filariform

39
Q

Inf stage to mosquitoes

A

Microfilaria

40
Q

Diagnostic stage to humans

A

Microfilaria or adults

41
Q

Infection usually acquired during____

• Take years to manifest
Adult worms in the lymph nodes cause
inflammation that obstructs lymphatic vessels ______

A

childhood

LYMPHEDEMA

42
Q

Clinical course:

A
  1. Asymptomatic
  2. Acute Stage
  3. Chronic Stage
43
Q

Clinical Spectrum of Lymphatic Filariasis

A
  1. Asymptomatic Microfilaremia
  2. Acute Dermatolymphangioadenitis
  3. Acute Filarial Lymphangitis
  4. Lymphedema and Elephantiasis
  5. Genitourinary Lesion such as hydrocoele
  6. Tropical Pulmonary Eosinophilia
44
Q

Lymphatic Localization:

• For parasitic survival

• Lymph is less

A

Less aggressive than blood

  • no platelet, no complement system
  • incomplete coagulation system
  • no granulocytes, slow flow
45
Q

Adult worm ___ (parasite-induced lymphatic dilatation

A

lymphangiectasis

46
Q

: parasite induced endothelial cell proliferation and differentiation leading to collateralization

A

Lymphangiogenesis

47
Q

• Predispose to secondary bacterial infections and inflammatory response to skin and subcutaneous tissue

A

Lymphangiectasis and Lymphangiogenesis

48
Q

Acute Stage
___________
• Main reservoir for mosquito vectors

• “Endemic Normals”

A

• Asymptomatic Microfilaremia

49
Q

Worm has suppressive immunoregulatory mechanism

• Individuals with thousands to millions motile microfilariae in PBS but no symptoms

A

Asymptomatic Microfilaremia

50
Q

Asymptomatic Microfilaremia

Outwardly healthy but may have hidden ____&_____ damage

A

lymphatic and kidney damage

51
Q

________

• From non-endemic person who transferred to endemic region

• Lymphadenitis, lymphangitis

A

Expatriate Syndrome

52
Q

• Clinical and immunologic hyperresponsiveness to the mature or maturing worms manifesting as allergic reactions like hives, rashes, and blood eosinophilia

A

Expatriate Syndrome

53
Q

_____________
• Most common acute manifestation of LF

• Localized pain, lymphadenitis, lymphangitis, cellulitis, local warmth

• Same lesion as erysipelas, cellulitis

A

Acute Dermatolymphangioadenitis (ADLA)

54
Q

• Acute Dermatolymphangioadenitis (ADLA) is caused by

A

• Caused by Group A Streptococcus

55
Q

• Directly caused by adult worms that died spontaneously or following treatment (evidence macrofilaricidal efficacy)

• Self-limited

A

Acute Filarial Lymphangitis (AFL)

56
Q

Acute Stage (4)

A

Asymptomatic Microfilaremia
Expatriate Syndrome
Dermatolymphangioadenitis (ADLA)
Acute Filarial Lymphangitis (AFL)

57
Q

Chronic Stage

A

Lymphedema and Elephantiasis

Hydrocoele

58
Q

• Characteristic Feature: fibrosis and cellular hyperplasia in and around the lymphatic walls

• Dead calcified adult worms: elicit immune response — lymphatic blockage — Lymphedema — Elephantiasis

A

Lymphedema and Elephantiasis

59
Q

: most common manifestation of chronic lymphatic filariasis

A

Lymphedema

60
Q

Elephantiasis: _______&raquo_space;> Wuchereria bancrofti

A

Brugia malayi

61
Q

Lower Extremities > Upper Extremities

• Increased risk to secondary bacterial infection

A

Elephantiasis

62
Q

• Results in the obstruction of lymphatics of______

• Clear or straw colored hydrocele fluid accumulate in closed sac of_____

________»> Brugia malayi

A

Hydrocoele

tunica vaginalis

testis

• Wuchereria bancrofti

63
Q

: rupture of lymphatics in the kidney manifested as milky urine

A

Chyluria

64
Q

Occult Filariasis
____________
• Microfilaria not found in blood but may be found in____

• Caused by immunologic hyperresponsivness to filarial infection

A

• Tropical Pulmonary Eosinophilia

tissues

65
Q

Paroxysmal nocturnal cough, hypereosinophilia diffuse miliary lesions

A

Tropical Pulmonary Eosinophilia

66
Q

Small epithelioid granuloma (Meyers-Kouwenaar bodies)

• Misdiagnosed as bronchial asthma or TB

A

Tropical Pulmonary Eosinophilia

67
Q

Diagnosis

A

Thick blood smear

DEC Provocative test

Circulating Filarial Antigens (CFA) Detection

Knott Concentration Method

68
Q

Thick Blood Smear

• Curved microfilaria:____
• Kinky microfilaria:_____

• Specimen collection best done at night______

•______ periodicity of the parasite

A

W. bancrofti
B. malayi

8pm to 4am

Nocturnal

69
Q

_____Provocative Test

• Stimulates microfilariae into coming out to the peripheral circulation allowing daytime collection of blood smear

A

DEC

70
Q

• Preferred method

• Can detect latent infections

A

Circulating Filarial Antigens (CFA) Detection

71
Q

• If low intensity infection

Collect 1 mL of blood + 10mL formalin. Shake. (Formalin lyses RBC) Centrifuge. (If no centrifuge, allow the tube to stand in upright position for 12 hours) Decant the supernatant fluid. Examine a drop of sediment on slide and cover slip.

A portion of sediment may be spread on a slide as thick smear and stain with Giemsa or Hematoxylin

A

Knott Concentration Method

72
Q

Treatment

_______: drug of choice

• Effective against adult and microfilaria

• Adverese events: fever, myalgia, headache, sore throat or cough lasting 24-48 hours; self-limited à symptomatic treatment

A

Diethylcarbamazine (DEC)

73
Q

Treatment

A

• Pain reliever
• Antibiotics for secondary bacterial infection
• Proper foot care program
• Surgery

74
Q

Prevention and Control

• Interrupt transmission of parasite via preventive chemotherapy

__________

A

Annual Diethylcarbamazine (DEC) plus Albendazole or Ivermectin in endemic area