Wuchereria bancrofti Brugia malayi Infective stage: Diagnostic stage: Mode of transmission: Habitat in humans:

Wuchereria bancrofti Brugia malayi Infective stage: Third stage larva Diagnostic stage: Microfilaria in blood (sheathed) Mode of transmission: Bite of mosquito (biological vector) Habitat in humans: Lymphatic channels and Lymph nodes

BLOOD AND TISSUE NEMATODES 1 Flashcards by Unknown Unknown

Wuchereria bancrofti Brugia malayi

Infective stage:
Diagnostic stage:
Mode of transmission:
Habitat in humans:

Wuchereria bancrofti Brugia malayi

Infective stage: Third stage larva
Diagnostic stage: Microfilaria in blood (sheathed)
Mode of transmission: Bite of mosquito (biological vector)
Habitat in humans: Lymphatic channels and Lymph nodes

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For parasitic survival
____________ is less aggressive than blood

lymph

no platelet
no complement system
incomplete coagulation system
no granulocytes
slow flow

(5)

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second leading cause of long term disability affecting both physical and psychological aspects (next to psychiatric illness)

Lymphatic Filariasis

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Wuchereria brancofti

brancoftian filaria

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Brugia malaya

malayan filaria

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Wucheria bancrofti Brugia Malayi

Common name
Final Host
Host adult
Diagnostic stage
Infective stage

Brancoftian’s filaria worm malayans filaria worm
Aepheles, aedes, culex Mansonia Bonneae, M. Uniformis
Lower lympathic Upper lympathic
Microfilaria Microfilaria
L3 filariform L3 filariform

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Give me the characteristics of Wuchereria Brancofti microfilaria

HBNT
Head (1:1)
Body (curve)
nuclei (does not have)
Tail tapper
Pale pink

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Characteristics of Brugia

Head (2:2)
Body (kinky)
Nuclei (scattered)
Tail tappers

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Wuchereria B. Brugia Malayi

Cephalic space
Sheath affinity to Giemsa
Body nuclei
Terminal nuclei
Appearance
Pathology

1:1 2:1
unstained stained pink
regulary shaped Overlapping /irregular shaped
none two nuclei
graceful curve kinky/stiff
Brancoftian filariasis Malayan filariasis

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Pathogenesis

Infection usually acquired _______________
Take years to manifest

Adult worms in the lymph nodes cause inflammation that obstructs lymphatic vessels ____________

Microfilariae DO NOT cause symptoms EXCEPT for __________

childhood
LYMPHEDEMA

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Lymphatic Localization:

Adult worm causes ________________ (parasite-induced lymphatic dilatation)

___________ parasite induced endothelial cell proliferation and differentiation leading collateralization to

lymphangiectasis
Lymphangiogenesis:

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___________
Common among those who grew up outside endemic regions
Characterized by clinical and immunologic hyper-responsiveness to the mature worms

1.
2.
3.
4.
5.

“Expatriate syndrome”

Hives, rashes and blood eosinophilia PLUS lymphangitis and lymphadenitis

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Clinical Spectrum of Lymphatic Filariasis

1.
2.
3.
4.
5.
6.

Pathogenesis
Clinical Spectrum of Lymphatic Filariasis
1. Asymptomatic Microfilaremia
2. Acute Dermatolymphangioadenitis
3. Acute Filarial Lymphangitis
4. Lymphedema and Elephantiasis
5. Genitourinary Lesion such as hydrocoele
6. Tropical Pulmonary Eosinophilia

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Asymptomatic Microfilaremia
_____________
Individuals with thousands to millions motile microfilariae in peripheral blood smear but no symptoms (but may have hidden lymphatic and kidney damage)

Main reservoir for infection
Worm has suppressive immunoregulatory mechanism
Inhibition of CD4 T cells was seen in Brugia infection

Endemic normals

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____________________________________
Most common acute manifestation of filariasis
1.
2.
3.
4.
5.

Recurrent and lasts ________ days
_______ incidence reports per patients

Acute Dermatolymphangioadenitis (ADLA)
Localized pain, lymphadenitis, lymphangitis, cellulitis, local warmth
1-16 days
1.5-7 incidence reports

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____________________
Same lesion as cellulitis which is caused by Group A ____________
Current evidence revealed that ________is bacterial in origin

Acute Dermatolymphangioadenitis (ADLA)
Streptococcus pyogenes

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________________________
Directly caused by adult worms that died spontaneously following treatment or (evidence macrofilaricidal efficacy)
Characterized by lymphangitis that progresses distally along the vessel producing a __________cord
Self-limited

Acute Filarial Lymphangitis (AFL)
“palpable”

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Characteristic Feature: ________ and _________ in and around the lymphatic walls
Dead calcified adult worms: ________, _______
_______________ most common manifestation of chronic lymphatic filariasis

Lymphedema and Elephantiasis
fibrosis and cellular hyperplasia
elicit immune response
→ lymphatic blockage
Lymphedema
→ Elephantiasis

Lymphedema

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_____________
Results in the obstruction of lymphatics of __________
Clear or straw colored hydrocele fluid accumulate in closed sac of testis
Wuchereria bancrofti&raquo_space;> Brugia malayi

Hydrocoele
Tunica vaginalis

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_____________
* Caused by rupture of lymphatics in the kidney and manifesting as __________
Blockage into the ___________ nodes divert lymph into renal lymph nodes causing them to rupture

Chyluria
milky urine
retroperitoneal lymph

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A bacterium that infects the filarial worms can also contribute to the chronicity of the filariasis
Once released from the dead worm, it can induce inflammation

Wolbachia

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Microfilaria not found in blood but may be found in tissues such as lungs and tissues
Caused by immunologic hyperresponsiveness to filarial infection (allergic reaction)
Paroxysmal nocturnal cough and eosinophilia
Misdiagnosed as bronchial asthma or TB

Tropical Pulmonary Eosinophilia

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Thick Blood Smear

Specimen collection best done at night
____________
__________periodicity of the parasite

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

8pm to 4am
Nocturnal
Diethylcarbamazine Provocative Test

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________________
-Preferred method
-Easier to do
-Can be used to diagnose a case with no microfilaria present in the blood
_________________
If low intensity infection

Circulating Filarial Antigens (CFA) Detection
Knott Concentration Method

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_____________ 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

Knott Concentration Method (KCM)

Treatment __________): drug of choice Effective against adult and microfilaria Given for _____ days Also good for _______ Adverse events: ____________ Due to the destruction of the adult worm and release of Wolbachia

Diethylcarbamazine (DEC 12 days TPE fever, myalgia, headache, cough lasting 24-48 hours; self-limited symptomatic treatment

Treatment ___________: not effective against adult worms and TPE Has same adverse effects as DEC but are milder Must be given for one year

Ivermectin

Treatment ___________ has added benefit of clearing intestinal helminths Must be given 6 to 12 months __________ anti-Wolbachia (bacteria inside filaria that is essential for growth, development, embryogenesis, and survival of filaria) May be given before the DEC

Albendazole Doxycycline:

Treatment Pain reliever Antibiotics for secondary bacterial infection Proper foot care program Washing the foot 2 x a day especially the skin folds Tap dry the affected limb Raising limbs at night to reduce swelling Surgery for hydrocoele

PAPS

Prevention and Control Interrupt transmission of parasite via _________ Annual Diethylcarbamazine (DEC) plus Albendazole or Ivermectin in endemic area Personal Protective Measure against mosquito

preventive chemotherapy

Loa loa * Infective stage: ___________ Diagnostic stage: ___________ * Mode of transmission: __________ * Habitat in humans: _____________

Loa loa * Infective stage: Third stage larva Diagnostic stage: Microfilaria in spinal fluid, urine, CSF, blood (sheathed) * Mode of transmission: bite of infected Chrysops fly * Habitat in humans: Adults are in subcutaneous tissue

LL Means ___________ Found in _____________ Vector: __________

Loa loa worm worm West Africa and Ethiopia African Eye Worm Chrysops fly (Deer fly, Horse fly, Mango fly) DHM

__________ * a transient subcutaneous swelling marking the migratory course through the tissues of the adult filarial eye worm of the genus Loa * The most common display of infection is the localized allergic inflammations called ______________ that signify the migration of the adult worm in the tissues away from the injection site by the vector.

Calabar Swelling

_________ visible movement of the adult worm across the surface of the eye; cause _________, _______, ________

eye worm congestion, itching, pain, and light sensitivity but little damage

Diagnosis Diurnal Periodicity of Loa loa microfilaria Daytime __________: Peripheral blood Identification of adult worm in the eye Antibody test for Loa loa

(10am to 2PM)

Characteristics of loa loa

Sheath stains lightly or not at all The nuceli in the body are coarse and crowded The body has irregular curves and can take on a corkscrew appearance Nuclei extend to tip of tail

Treatment _____________ Effective against microfilariae and adult worms __________ May be given if DEC is not effective after repeated treatment ____________ of adult worm

Diethylcarbamazine (DEC) Albendazole Surgical removal

Prevention

May take weekly Diethylcarbamazine if visiting endemic area Use insect repellant Use clothing that covers most of the skin

Onchocerca volvulus * Infective stage: ____________ Diagnostic stage: ____________ * Modes of transmission: ______________ * Habitat in humans: _____________________

Onchocerca volvulus * Infective stage: third stage larva Diagnostic stage: (1) Microfilaria in subcutaneous tissue (2) Adult in subcutaneous nodules * Modes of transmission: bite of Simulium (black fly) * Habitat in humans: Adults are found in subcutaneous nodules

Characterized by cutaneous and ocular pathology that occurs after the invasion and death of microfilariae in the skin and eye while adult worms are enclosed in nodules (onchocercomas) in the subcutaneous and deeper tissues.

Onchocerciasis

Pathogenesis _______is an eye and skin disease. Symptoms are caused by the ___________-, which move around the human body in the subcutaneous tissue and induce intense inflammatory responses when they die. * The presence of microfilariae in the eye and indeed in the skin usually does not cause much problem. On the other hand, dead or dying microfilariae trigger an inflammatory cascade that leads to tissue damage associated with the disease. * Wolbachia species have been found to be endosymbionts of O. volvulus adults and microfilariae, and are thought to be the driving force behind most of O. volvulus morbidity.

Onchocerciasis microfilariae

Pathogenesis * Onchocerciasis is an eye and skin disease. __________ most serious manifestation * Simulium sp. black flies, intermediate hosts that require fast-flowing water for their breeding and development the disease is thus restricted to areas adjacent to river systems.

River blindness:

Pathogenesis ____________The large adult female worms are contained within fibrous nodules or onchocercomas in subcutaneous or deeper tissues. The smaller adult males appear to circulate from nodule to nodule to inseminate the females

Onchocercoma

Pathogenesis ____________ due to allergic reaction - towards the migrating microfilariae * The more common generalized form presents with subclinical or intermittent dermatitis that may progress to skin hyperpigmentation or depigmentation (lizard skin) and atrophy with loss of elasticity (hanging groin)

Pruritus, dermatitis

Skin Snips: Microfilaria (Anytime) - - Biopsy of Skin Nodules: Adult worm with Wolbachia

* Wet Mount * Stained with Giemsa or Hematoxylin

Sheathed, no nuclei in the tip of the tail

1. Wuchereria Brancrofti

Sheathed, 2 distinct nuclei in the tip of the tail

Brugia malayi

Sheathed, nuclei extending to the tip of the tail

Loa loa

Unsheathed, no nuclei in the tip of the tail

Onchocerca volvulus

Treatment and Prevention ___________ kills larvae but not the adult Thus should be given every 6 months for the life span of the adults (10-15 years) ______________ kills Wolbachia Old drugs but no more recommended: ________________ Kills adult accelerrates river blindness

Ivermectin Dioxcycline Diethylcarbamedazine

Prevention of loa loa

Prevention Insect repellant Wearing clothes covering skin

Dracunculus medinensis Infective stage: Diagnostic stage: Mode of transmission: Habitat in humans:

third stage larva female worm and rhabditiform larva drinking water with infecting copepods maturation takes place in abdominal cavity

Dracunculus medinensis Infective stage: Diagnostic stage: Mode of transmission: Habitat in humans:

third stage larva female worm and rhabditiform larva drinking water with infecting copepods maturation takes place in abdominal cavity

fiery serpent little dragon from medina guinea worm

dracunculus medinensis

The ________ dies in the host tissue, while the ________ migrates to the host's subcutaneous tissue. The ________ causes the formation of a blister on the skin's surface, generally on the lower extremities, though occasionally on the hand or scrotum. When the blister ruptures, the female slowly emerges over the course of several days or weeks

Dracunculus medinensis male female female

______________ _____________: as it emerges to the subcutaneous tissue, it release toxic chemical ________ If fails to reach the skin → Gets calcified in the joint _________ Reaches CNS→ ___________ Abscess and swelling when worms rupture Secondary bacterial infection on blisters or ulcers

Dracunculus medinensis Female adult worm rash at site, diarrhea, localized edema, reddish papule, blister, and itching arthritis paraplegia

Diagnosis Recovery of adult worm from the blister Fluid discharged by the worm: ______

L1 larvae

Treatment Manual Removal of Adult Female Worm

Submerging the affected body part in water to help coax the worm out. TREATMENT The site is then cleaned thoroughly. Then, slight pressure is applied to the worm as it is slowly pulled out of the wound. To avoid breaking the worm, pulling should stop when resistance is met. Full extraction of the female guinea worm usually takes several days.

Maximum length of dracunculus medinensis

31 inches (800 mm)

Treatment Antihistamine ___________: for severe allergic manifestations Anti-helminthic Agents: - - -

Epinephrine Thiabendazole, metronidazole, and mebendazole

prevention of dracunculus medinensis

CVSP Prevention Case Containment Safe drinking practices Vector Control Patient education