BLOOD AND TISSUE NEMATODES 1 Flashcards
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
For parasitic survival
____________ is less aggressive than blood
lymph
- no platelet
- no complement system
- incomplete coagulation system
- no granulocytes
- slow flow
(5)
second leading cause of long term disability affecting both physical and psychological aspects (next to psychiatric illness)
Lymphatic Filariasis
Wuchereria brancofti
brancoftian filaria
Brugia malaya
malayan filaria
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
Give me the characteristics of Wuchereria Brancofti microfilaria
HBNT
Head (1:1)
Body (curve)
nuclei (does not have)
Tail tapper
Pale pink
Characteristics of Brugia
Head (2:2)
Body (kinky)
Nuclei (scattered)
Tail tappers
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
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
Lymphatic Localization:
Adult worm causes ________________ (parasite-induced lymphatic dilatation)
___________ parasite induced endothelial cell proliferation and differentiation leading collateralization to
lymphangiectasis
Lymphangiogenesis:
___________
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
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
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
____________________________________
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
____________________
Same lesion as cellulitis which is caused by Group A ____________
Current evidence revealed that ________is bacterial in origin
Acute Dermatolymphangioadenitis (ADLA)
Streptococcus pyogenes
________________________
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”
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
_____________
Results in the obstruction of lymphatics of __________
Clear or straw colored hydrocele fluid accumulate in closed sac of testis
Wuchereria bancrofti»_space;> Brugia malayi
Hydrocoele
Tunica vaginalis
_____________
* 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
- 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
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
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
________________
-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
_____________
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
-
Biopsy of Skin Nodules: Adult worm with Wolbachia
- Wet Mount
- Stained with Giemsa or Hematoxylin
Sheathed, no nuclei in the tip of the tail
- 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
