Tissue nematodes
What are tissue Nematodes
1- T. spiralis
2- Dracanculus Medinensis
2- Filarial Worms
W. Bancrofti
W. Malayi
Onchocerca Volvulus
Loa Loa
What are the Hosts of T.Spiralis
Definitive : Man
Intermediate : Pigs / rats
Habitat of T. spirals
Adults : Small Intestine
Encysted Larva : Striated Muscles
Mode of infection and infective stage of T. spirals
Ingestion of Encysted Larvae
is man dead-end host to T.spirals unlike rates and pigs ?
Yes
Life cycle of T.spiralis
Encysted larvae → Larvae (intestine)
Larvae → adult
adult ---lay--→ motile larvae (circulation)
larvae are deposited in many tissues as Muscles
Muscle Cell filled with larvae of T.spiralis is called
Nurse cell
Pathogensis/ clinical Manifestation of T.spiralis
most characterizing one : HIGH Eosinophilia
Name of Drancanculus Medinensis
Medina/ Guinea worm
Hosts of D. Medinensis
D → Man
R → Dogs
I → Cyclops
Habitat of D. Medinensis
Subcutaneous Tissue
Mode Of infection and infective stage
ingestion of cyclops / infective larvae
life cycle of D. medinensis
Larvae 1- penetrate gut mucosa
2- turn into adults
adults → move to skin surface of lower limb
Clinical Manifestation of D. Medinensis
Blisters formation
General Characteristics of Filarial Worms
Slender, Thread-like
Females are bigger than males
Viviparous
Classified by Habitat into ( Lymphatics , subcutaneous, skin)
Microfilaria - are found in blood mostly
and have periodicity
Lymphatic Filarial Worms
1- W. Bancrofti
2- W. Malayi
S.C filarial Worms
1- Onchocerca Volvulus
2- Loa Loa
Habitat of Microfilaria
Blood
except Onchocerca Volvulus (S.C)
Periodicity of Microfilaria
1- Nocturnal
2- Diurnal
3- Non-periodic
Nocturnal Periodicity with examples
Microfilaria reach maximum activity at Midnight
Lymphatic Filarial Worms
Diurnal Periodicity with examples
Microfilaria reach maximum activity at Mid-day
Loa Loa
Non-periodic Periodicity with examples
no increase or decrease in activity at certain times
Onchocerca Valvulus
Hosts of W. Bancrofti
D → Man
I → Female Culex Pipiens
Habitat of W. Bancrofti /W. Malayi
adults → Lymphatics
Microfilaria → Blood
Diseases of W. Bancrofti
Bancroftian filariasis / Elephantiasis
Mode of infection/ infective stage of W. Bancrofti
Female Culex Pipien biting
larva
Life cycle of W. Bancrofti / W. Malayi
in Mosquito
microfilaria → 3rd stage filariform larva (through ex-sheathing & Molts)
in Man
Larva→ adult (in lymphatics) ---lay→ microfilaria
pathogenesis of W. Bancrofti /W. Malayi
Blockage of Lymphatics & infiltration
Clinical Manifestation of W. Bancrofti
Hematuria, proteinuria
Adenolymphangitis
local adema
Differences Between W. Bancrofti and W. Malayi
Intermediate host
Reservoir host
Disease
otherwise they are similar
Name of W. Malayi
Brugia Malayi
Disease of W. Malayi
Malayian Filariasis
Intermediate host of W. Malayi
Mansoni Mosquito
Reservoir host of W. Malayi
Dogs, Cats, Monkeys
What are S.C Filarial Worms
Loa Loa
Onchocerca Volvulus
Name of Loa Loa
African Eye Worm
Disease of Loa Loa
Loiasis / Calabar Worms
Hosts of Loa Loa
D → Man
I → Chrysops (Mango, deer fly)
Habitat of Loa Loa
Subconjunctival tissue and S.C tissue
Mode of Infection / Infective Stage of Loa Loa
Ingestion of Chrysops containing 3rd stage larva
life Cycle of Loa Loa
in fly
microfilaria → 3rd stage filariform larva (through ex-sheathing & Molts)
in Man
Larva→ adult ---lay→ microfilaria
Hosts of Onchocerca Volvulus
D → Man
I → Black fly/Simulim
Disease of Onchocerca Volvulus
Onchocercosis / River Blindness
Habitat of Onchocerca Volvulus
S.C tissue
Mode of infection/ infective stage of Onchocerca Volvulus
ingestion of Black Flies containing infective larva
Life cycle of Onchocerca Volvulus
in fly
microfilaria → 3rd stage filariform larva (through ex-sheathing & Molts)
in Man
Larva→ adult ---lay→ microfilaria