Tissue Nematodes

Tissue Nematodes
Dr Monica Puspa Sari, M.Biomed

Classification – Tissue Nematodes
Lymphatic Wuchereria bancrofti
Brugia malayi
Brugia timori
Subcutaneous Loa loa (african eye worm)

Onchocerca volvulus (blinding filaria)
Dracunculus medinensis (thread worm)
Conjunctiva Loa loa

Wuchereria bancrofti (Filarial worm)
BANCROFTIAN FILARIASIS/BANCROFTIAN WUKERERIASIS
Definitive host Man
Intermediate host Female Culex, Aedes or

Anopheles mosquito
Infective form Third stage larva
Mode of transmission Inoculation – bite of mosquito
Site of localization Lymphatics / lymph nodes of

man
Geographical India, China, Far East, Africa,
distribution South & Central America
B.timori
Brugia spesies B. malayi
Brugian Filariasis
Definitive host Man
Intermediate host Mansonia species, Anopheles
Geographical distribution South-east Asia, China, India,
Indonesia, Pacific Islands (B.m)
Timor island o Indonesia (B. t)

Morphology-Microfilariae
W. bancrofti
B. malayi
B. timori
Morphology-Adults
Male and female adult worm
 Male : 2.5 – 4 cm
 Female : 5 to 10 cm
Periodicity-Microfilariae
 Nocturna
 Subperiodic diurna : pasific

Life cycle
Global distribution of LF
Clinical manifestations of LF
o Initially asymptomatic (asymptomatic amicrofilaremia, asymptomatic
microfilaremia)
o Symptoms develop with increasing numbers of worms
o Less than 1/3 of infected individuals have acute symptoms
o Manifestations are two types :
1. Lymphatic filariasis (presence of adult worms)
2. Occult filariasis (Immuno hyperresponsiveness)
27/04/08 Dr Ekta, Microbiology

Clinical spectrum
Asymptomatic
None Filarial fever
microfilaremia
Chronic
TPE
pathology
Stage of Acute Manifestation
 Recurrent episodes of acute inflammation in the

lymph vessel/node of the limb & scrotum
 Related to bacterial & fungal super infections of the
tissue
 Consisting of :
1. Filarial fever (ADL-DLA)
2. Lymphangitis
3. Lymphadenitis
4. Epididimo orchitis
Chronic manifestations
 Permanent damage to the lymph vessels  adults
worms, the pathological changes  dilation of the
lymph vessels.
 It starts with pitting oedema  browny oedema
leading to hardening he tissue.
 Hyperpigmentation, caratosis, wart like lesions
 Hydrocele (40-60%), Elephantiasis of scrotum, penis,
leg, arm, vulva, beast, Chyluria.
Occult or Cryptic filariasis
 Results of hyper responsiveness to filarial antigens
derived from microfilariae.
 Symptoms : paroxysmal cough and wheezing, low
grade fever, scandy sputum with occasional
haemoptysis, adenopathy and increased eosinophilia,
 X-ray : diffused nodular mottling and interstial
thickening
Hydrocele
Leg
Arm
Breast
Chyluria & Haematuria
Classification of Lymphoedema
 Lymphoedema  7 stages
1. Oedema
2. Folds
3. Knobs
4. Mossy foot
5. Disability
Stages of Lymphoedema of the Leg (Stage I)
 Swelling reverses at
night
 Skin folds-Absent
 Appearance of Skin-
Smooth, Normal
Stages of Lymphoedema of the Leg (Stage II)
 Swelling not
reversible at night
 Skin folds-Absent
 Appearance of skin-
Smooth, Normal
Stages of Lymphoedema of the Leg (Stage III)
 Swelling not
reversible at night
 Skin folds-
Shallow
 Appearance of
skin-Smooth,
Normal
Stages of Lymphoedema of the Leg (Stage IV)
 Swelling not
reversible at night
 Skin folds-Shallow
 Appearance of skin
- Irregular,
 * Knobs, Nodules
Stages of Lymphoedema of the Leg (Stage V)
 Swelling not
reversible at night
 Skin folds-Deep
– Smooth or
Irregular
Stages of Lymphoedema of the Leg (Stage VI)
 Swelling not
reversible at night
 Skin folds-Absent,
Shallow, Deep
*Wart-like lesions on
foot or top of the
toes
Stages of Lymphoedema of the Leg (Stage VII)
 Swelling not
reversible at night
 Skin folds-Deep
 Appearance of skin-
Irregular
 Needs help for daily
activities - Walking,
bathing, using
bathrooms, dependent
on family or health care
systems
DIAGNOSIS
 Demonstration of Microfilariae in the peripheral blood

1. Thick blood smear : 2-3 drops of free flowing blood by finger prick
method, stained with JSB-II
2. Membrane filtration method: 1-2 ml intravenous blood filtered
through 3µm pore size membrane filter
3. DEC provocative test (2mg/Kg): After consuming DEC,
mf enters into the peripheral blood in day time within 30 - 45 minutes.
 Immuno Chromatographic Test (ICT) : Antigen detection assay
can be done by Card test and through ELISA. Circulating Filarial Antigen
detection is regarded as “Gold Standard” for diagnosing W. bancrofti
infection.
 Quantitative Blood Count (QBC): identify the microfilariae and will help in
studying the morphology.
 Ultrasonography: using a 7.5 MHz or 10 MHz probe, the movements of
living adult worms of W.b. (Filarial dance sign) in the scrotal lymphatics
of asymptomatic males with microfilaraemia.
 Lymphoscintigraphy: The structure and function of the lymphatics
of the involved limbs after injecting radio-labelled albumin or dextran in the
web space of the toes. The structural changes can be imaged using a
Gamma camera.
 X-ray Diagnosis : diagnosis of Tropical pulmonary eosinophilia.
Picture will show interstial thickening, diffused nodular mottling.
 Haematology : Increase in eosinophil count
ICT
TREATMENT
 DEC (diethylcarbamazine citrate)
Kills microfilariae and “damages” adults
 Ivermectin
Kills microfilariae but not adult worms
 Albendazole
Affects adults but NOT microfilariae
 Doxycycline – remember Wolbachia?
 Combination therapy
THANKS YOU

Tissue Nematodes

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Tissue Nematodes

Dr Monica Puspa Sari, M.Biomed

Subcutaneous Loa loa (african eye worm)

Conjunctiva Loa loa

Definitive host Man

Intermediate host Female Culex, Aedes or

Infective form Third stage larva

Mode of transmission Inoculation – bite of mosquito

Site of localization Lymphatics / lymph nodes of

Brugia spesies B. malayi

Definitive host Man

Intermediate host Mansonia species, Anopheles

Geographical distribution South-east Asia, China, India,

Indonesia, Pacific Islands (B.m)

Timor island o Indonesia (B. t)

Male and female adult worm

 Subperiodic diurna : pasific

27/04/08 Dr Ekta, Microbiology

 Recurrent episodes of acute inflammation in the

 Demonstration of Microfilariae in the peripheral blood

 Doxycycline – remember Wolbachia?

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