Filaria - ocw.usu.ac.idocw.usu.ac.id/.../tmd175_slide_filaria.pdf · •Vivipar •The larva is called microfilaria •The internal structure f the microfilaria is very important

Filaria

FILARIA

Parasitology Department

Medical Faculty of USU

• Superfamily Filarioidea

• Family Acanthocheilonematidae

• Widespread in the tropic, subtropic, and

temperate zones

FilariaGeneral

8/28/2009 Dewi M. Darlan 2

temperate zones

• Many species known as parasite in humans:

Wuchereria bancrofti, Brugia malayi, B.

timori, Loa loa, and Onchocerca volvulus

• Vector: blood-sucking insects

• Vivipar

• The larva is called microfilaria

• The internal structure f the microfilaria is very

important for the diagnosis of filariasis

FilariaGeneral


• Filaria is devided 3; based on their habitat

such as:

1. Lymphatic Filaria

2. Cutaneous Filaria

3. Body Cavity Filaria

Lymphatic Filaria

• Consist of:

– Wuchereria bancrofti


– Wuchereria bancrofti

– Brugia malayi

– Brugia timori

Wuchereria bancrofti

• This worm is responsible for 90% of lymphatic

filariasis in the worldwide.

• Vivipar;


• Vivipar;

• Infective stage: Larvae st.3

• The larva was found by Demarquay (1863) and

Wucherer (1866)

• The adult was first found by Bancroft in 1876

• Nocturnal periodicity

Morphology

• Microfilaria:– Sheath (+)– Cephalic space:

Cephalic space

Body nuclei


Length = wide (1:1)– Body Nuclei :

Discrete (Regular)– Body curve: Smooth– Tail: No nuclei at the

tip of the tail

Tip of the tail

Morphology

• Adult worm:– Long-slender w/ smooth cuticle and bluntly

rounded ends– The head is slightly swollen and bears two


– The head is slightly swollen and bears two circles of well defined papillae

– The mouth is small and lack of buccal capsule– Males: ± 40mm long and 100µm wide– Females: ± 6cm-10cm long and 300µm wide

Life cycle:

Vector: transmission larvae std.3 through

wound puncture

Resting stageMosquito ingest the mf

8/28/2009 Dewi M. Darlan 8Thoracic duct

Lymphatic system

Microfilariae

At the blood circulation

Epidemiology

• Host can be infected; there is no host reservoir

• Periodicity: Nocturnal

• Rural strain :– An. letifer ; – An. Maculatus ; – An. whartoni


• Periodicity: Nocturnal – An. whartoni – An. balabacensis- S– An. flavirosrtis - S– An. leucosphyrus

Vector:Urban strain :•Culex quinquefasciatus•Culex fatigans

Brugia malayi

• The larva was first observed from a native Sumatera by Brug (1927)




• Vector: Mansonia uniformis (rural) and Anopheles spp. (urban)

Brugia malayi

• Morphology:– Adult worm:�Males:

• 13.5-20.5 mm long and 70-80 µm wide


• Tail is curved ventrally and Spicules are unequal and dissimilar

�Females: • 80-100 mm long and 240-300 µm wide• Fingerlike tail cover with minute cuticular bosses

• Microfilaria:

– Sheath (+) stained; pinkish-red

– Cephalic space:

length : wide = 2:1

– Body nuclei: overlapping;

Ceph.

space

Body nuclei

Morphology


– Body nuclei: overlapping; irregular

– Body curve: wrinkled

– Presence of sub-terminal and terminal nucleus

Sub-terminal

nukleus

Terminal

nukleus

Brugia timori

••Overlapping body Overlapping body nucleinuclei��Sheath does not Sheath does not

stain pinkish but stain pinkish but

(bluish)(bluish)


(bluish)(bluish)

��Cephalic space Cephalic space

elongated, ratio elongated, ratio

1:31:3

��Presence of subPresence of sub--

terminal and terminal and

�� terminal nucleusterminal nucleus

Assignment

�List morphologic differentiations among microfilariae of W.


microfilariae of W. bancrofti, B. malayi, and B. timori

Cutaneous filaria

• Consist of:– Onchocerca volvulus


– Onchocerca volvulus– Loa-loa

Onchocerca volvulusGeneral

• Final host is humans, causes onchocercosis

(river blindness, the blinding filarial d’ses,

Robles d’ses)

• Vector: females of Simulium spp. (black fly)


• Vector: females of Simulium spp. (black fly)

• Distributed in Africa and Central and South

America

• Adults are tangled together in a tumor

(onchocercoma) formed in the subcutaneous

tissue

Onchocerca volvulusGeneral

• Microfilariae are occasionally found

in peripheral vessels, but normally

stay i/t lymph sinuses near the body

surface o/t host


surface o/t host

• Female is 30-50 cm, male is only 2-

4.5cm long

• Microfilaria is 0.22-0.36mm,

unsheated, bulbous head, no

terminal nucleus

Onchocerca volvuluslife cycle

• Adults live in onchocercoma

• Insect bites and sucks hydrocele and

microfilaria from the tumor, and get infected

by the larvae


by the larvae

• Microfilariae enter insect’s chest muscles →molt twice → become infective → get out o/t

chest to proboscis

• Microfilariae will be injected to a human

through the bite o/t insect

Onchocerca volvulusMorphology

• Microfilaria:– Unsheath– Body nuclei separated

Cephalic

space


(moderately compact)– Cephalic space: 1:2– End: tapered & flexed– No terminal nucleus

• Vector: Simulium fly

end


Loa-loaGeneral

• Also called the African eye worm

• Causes Loaiasis (Calabar swelling)


swelling)

• Adults in subcutaneous tissue, esp. conjunctivae

• Spead in tropical Africa

• Final host: humans and apes

• Vector: Chrysops spp.

Loa-loaMorphology

• Microfilaria:– Sheath (+) un-stain– Body nuclei as

compact column of


compact column of nuclei that extends to the tail

– Short cephalic space, ration 1:1

– No terminal nucleus

Loa-loaMorphology

• Female is 5-7cm, and male is 3-3.5cm long

• Microfilaria is 0.25-0.3mm, sheated

• Diurnal periodicity (neither fluorescent


• Diurnal periodicity (neither fluorescent substance nor granules are found in its body)

• Vector: Chrysops fly


Dracunculus medinensisGeneral

• Also called dragon worm

• Final host: mainly humans

• Distributed in Middle East and


• Distributed in Middle East and Southeast Asia

• I’mediate host: Cyclops• Habitat is subcutaneous tissues

Dracunculus medinensisGeneral

• Adult female is very thin and long, 70-120cm long, male is very short, being only 4cm long


long

D. medinensisLife Cycle



Documents

Filaria - ocw.usu.ac.idocw.usu.ac.id/.../tmd175_slide_filaria.pdf · •Vivipar •The larva is called microfilaria •The internal structure f the microfilaria is very important