Wuchereria bancrofti is a parasitic roundworm that causes lymphatic filariasis. It lives in the lymphatic system of humans and is transmitted by mosquitoes. The adult female worms release microfilariae that circulate in the bloodstream and can be detected via blood smears between 8 PM and 4 AM. Infection leads to swelling of the limbs and genitals known as elephantiasis. Diagnosis involves blood smears to detect microfilariae while treatment consists of medications like diethylcarbamazine, ivermectin, and albendazole. Prevention focuses on mosquito control and public education.

1. Wuchereria bancrofti

2. Wuchereria
bancrofti
is a human
parasitic
roundworm
that is the
major cause
of lymphatic
filariasis.

3. Superfamily: Filariodea
Subfamily: Acanthocheilonematinae
Genus: Wuchereria
Specie: W. bancrofti

4. Otto Wucherer Joseph Bancroft
W. bancrofti was named after physician Otto
Wucherer and parasitologist Joseph Bancroft.

5. Morphology
Adult worms (dioecious):
Female 80- 100 mm in length
ovoviviparous
Male 40 mm by 0.1 mm

6. Morphology
Microfilariae:
 244- 296 um by 7.5- 10 um
 Nuclei not reaching tail end
 No terminal nuclei
 Nuclei regularly spaced, dispersed
 Bigger, wider than B. Malayi
 Graceful sweeping curves
 Short head space (as long as
broad)
 Sheath unstained with Giemsa
 Bluntly rounded anteriorly and
pointed caudally

7. Microfilaria - is a miniature adult that retains the egg
membrane as a sheath.

8. Characteristics
Habitat of Adult worm : Lymphatic system
Habitat of Microfilaria: Blood
Intermediate Host : Anopheles minimus
var. Flavirostris
- principal vector for malaria in
Philippines
- bite indoors, night- biters
Others: Aedes poecilus ( in axils of plants)
Definitive Host : Man

9. Characteristics
Periodicity: Nocturnal periodicity, EXCEPT
South Pacific microfilariae
Nocturnal periodicity:
8 PM- 4 AM = best time to collect
Microfilariae may not be demonstrable in peripheral blood
if:
- low intensity of infection
- dead worms
- obstructed lymphatics

10. Life Cycle

11. Epidemiology
 Tropical areas
worldwide
 India
 SEA
 Pacific Islands
 Africa
 South America
 Central America

12. Epidemiology
 Philippines
 Camarines Sur/ Norte
 Albay
 Sorsogon
 Mindoro
 Masbate
 Romblon
 Marinduque
 Bohol
 Samar
 Leyte
 Palawan
 Mountain Province
 All provinces of Mindanao

13. Pathogenesis
 Lymphedema
• abnormal accumulation
of lymph in tissues
causing swelling of
arms, breasts, or
genitals.

14. Pathogenesis
 Elephantiasis
• disabling and
disfiguring lymphedema
of the limbs, breasts,
and genitals,
accompanied by marked
thickening of the skin.

15. Pathogenesis
 Hydrocoele
• fluid- filled balloon-
like enlargement of the
sacs around the testes.

16. Diagnosis
 Direct methods (visualization of larval stage or
microfilaria and adult worm)
Microfilaria can be seen on peripheral blood or other body fluids (eg.
urine, ascitic, hydrocoele, or lymph fluid).
 Wet smear examination under the microscope where motility
can also be seen
 Examination of stained peripheral blood smear which is also
useful in species identification based on morphologic features
of organism, especially the tail end
 Thick or concentrated blood smears
 concentration smears are useful in patients with low parasetimia
 blood sample is taken during the period in the day when the
juveniles are in the peripheral circulation.

17. Diagnosis
 Direct Methods
 X- ray
 adult worms can be demonstrated in lymph node biopsy
 calcified adult worms are visualized
 Doppler Ultrasonography
 detect presence of motile adult worms in dilated lymphatics

18. Diagnosis
 Indirect Methods
 Peripheral blood eosinophilia
 Elevated serum IgE concentration
 Presence of antifilarial serum antibody
 Intradermal complement fixation tests

19. Treatment
 diethylcarbamazine (DEC)
 ivermectin
 oralbendazole

20. Prevention and Control
 Insect repellants
 Use of mosquito nets
 Public education

21. END