Filariasis

1. SLIDE SEMINAR- FILARIASIS
Dr. Krishna LekhaT
Junior Resident

2. Microfilaria of Wuchereria bancrofti
Leishman stained thin smear
sheathed microfilaria
Length – 290߂m
diameter – 6 -7 ߂m
sheath faintly stained
Cephalic space – equal length and
breadth
 Tail end – nuclei don’t extend till tail tip

3. Microfilaria of Wuchereria bancrofti
Giemsa stained thick smear
sheathed microfilaria
Length – 290߂m
diameter – 6 -7 ߂m
sheath faintly stained
Cephalic space – equal length and
breadth
 Tail end – nuclei don’t extend till tail tip

4. Classification
• Kingdom – Animalia
• Phylum – Nemathelminthes
• Class – Chromodorea
• Order – Rhabditida
• Family - Filarioidea

5. General features of Nemathelminthes
• Elongated, cylindrical, unsegmented body
• Complete alimentary canal with anal opening
• Diecious
• Only 1 host (except in Filarial worms and Dracunculus)
• Either oviparous or viviparous

6. General features of Filarial worms
• Adult worm – 8-100 mm X 0.25 – 0.30 mm
• Female longer than male
• Habitat – lymphatic system, subcutaneous tissue or serous body
cavity
• Female gives birth to Microfilaria
• Sheathed / Unsheathed microfilaria

7. Microfilaria
Sheathed Microfilaria
Tail end
Nuclei don’t extend up
to tail tip
Wuchereria
bancrofti
Nuclei extend
up to tail tip
Nuclei present
in a single row
Loa loa
Two nuclei at
the tip
Brugia malai
Unsheathed Microfilaria
Tail end
Nuclei don’t extend up
to tail tip
Mansonella
ozzardi
Onchocerca
volvulus
Nuclei extend up to tail
tip
Mansonella
perstans
Mansonella
streptocerca

8. Classification of Filarial worms– habitat in human body
Lymphatic Filariasis Subcutaneous Filariasis Serous cavity Filariasis
Wuchereria bancrofti Loa loa Mansonella perstans
Brugia malai Onchocerca volvulus Mansonella ozzardi
Brugia timori Mansonella streptocerca

9. Lymphatic Filariasis

10. Wuchereria bancrofti
• Morphology - Adult form, microfilarial form
Adult worm
Size – female (70-100 X 0.25 mm)
male (25-40 X 0.1 mm)
Female –Viviparous
10 -15 years life span

11. Microfilaria
• Length – 250-300 ߂m
• Thickness – 6-10 ߂m
• Do not undergo any development in human body
• Life span – 2-3 months
• Periodicity
Nocturnal periodicity – 10pm – 4am
Day time –capillaries of lung, kidney, heart and great vessels

13. Clinical features
• Classical filariasis
• Occult filariasis
Classical Occult
Blockage due to mechanical
factors or allergic
inflammatory reactions to
the worm antigens and
secretions
Hypersensitivity reactions
to the filarial antigens
ADL (acute
adenolymphangitis)
Massive eosinophilia
Hydrocoele Hepatomegaly
Lymphorrhagia Meyer’s Kouwenaar
syndrome
Elephantiasis Tropical pulmonary
eosinophilia

14. Laboratory diagnosis
• Demonstration of microfilaria  thin film, thick film
Collection of sample – 10pm – 4am
Concentration techniques - microfilaria density is low
1. Knott’s concentration technique
2. Nucleopore filtration technique
3. DEC provocation test
Unstained smear – motility of microfilaria
Stained smear - Giemsa, Leishman stain

15. Thick smear preparation

16. Thin smear preparation

17. Romanowsky Stains
May Grunwald – Giemsa stain
Jenner’s stain
Wright’s stain
Leishman’s stain
Field’s stain

18. Others
Direct demonstration
Lymph node biopsy - adult worm
Radiological investigation – USG
X ray
Serodiagnosis - Demonstration of antibody
Demonstration of antigen – ICT, ELISA
Molecular diagnosis –PCR – detection of filarial DNA
Indirect evidence – Eosinophilia in blood
Elevated Ig E levels

19. Treatment
• DOC – Di-Ethyl Carbamazine
• Other drug – Ivermectin -150mg/kg body weight
Schedule Dose
Day 1 50mg
Day 2 50mg 1-1-1
Day 3 100mg 1-1-1
Day 4-21 5 mg/kg/day in 3
divided doses

20. Elimination of Lymphatic filariasis
Guidelines for Mass drug administration (MDA)
• Given in once a year, on the identified day (National filaria day)
• Drugs should be administered under the observation of administrator (DOT)
Age in
years
DEC
Dose No. of
tablets
Albendaz
ole
(400 mg)
< 2 years Nil Nil Nil
2-5 years 100mg 1 tablet 1 tablet
6-14 years 200 mg 2 tablet 1 tablet
15 & above 300mg 3 tablet 1 tablet

21. Lymphatic filariasis

22. Wuchereria bancrofti
Giemsa stained thick smear
sheathed microfilaria
Length – 290߂m
diameter – 6-7 ߂m
sheath faintly stained
Cephalic space – equal length and
breadth
 Tail end – nuclei don’t extend till tail tip

23. Brugia malai
Giemsa stained thick smear
Sheathed Microfilaria
Length -230 ߂m
Diameter- 6 ߂m
Sheath – deeply stained
Cephalic – length: width ratio – 2:1
Tail end – Nuclei extend till tail tip
2 discrete nuclei

24. Brugia timori
Giemsa stained thick smear
Sheathed microfilaria
Size – 310 ߂m
Sheath – unstained
Cephalic – length : width ratio – 3:1
Tail end – Nuceli extend till tail end
Chain 0f 5-8 nuclei

25. Subcutaneous filariasis

26. Loa loa
Giemsa stained thick smear
Sheathed microfilaria
Length– 300 ߂m
Sheath – unstained
Tail end – Nuclei extend till tail end

27. Onchocerca volvulus
H & E stained smear prepared from skin nodule
Unsheathed microfilaria
Length– 300 ߂m
Diameter- 6-8 ߂m
Tail end – Nuclei don’t extend till tail tip

28. Mansonella streptocerca
H & E stained smear from skin lesions
Unsheathed microfilaria
Length– 180-240 ߂m
Diameter-3 ߂m
Tail end – Crook like curve
Nuclei extend till tail end

29. Serous cavity filariasis

30. Mansonella perstans
Giemsa stained Peripheral thick smear
Unsheathed microfilaria
Tail end – blunt, nuclei extend till tail tip

31. Mansonella ozzardi
Giemsa stained Peripheral thick smear
Length – 175-240 ߂m
Diameter- 4.5 ߂m
Unsheathed microfilaria
Tail end – sharply pointed, nuclei don’t
extend till tail end

32. Refference
• Chatterjee KD. Parasitology: protozoology and helminthology. 2018.
• Paniker CJ, Ghosh S. Paniker's textbook of medical parasitology. JP Medical
Ltd; 2017 Sep 14.
• Sastry AS, Bhat S. Essentials of medical parasitology. Jp Medical Ltd; 2018
Oct 31.
• MackieTJ, McCartney JE, Collee JG. Mackie & McCartney practical medical
microbiology. (NoTitle). 1989.
• https://www.cdc.gov/parasites/lymphaticfilariasis/index.html

33. ThankYou