BLOOD, BONE MARROW, SPLEEN
AND LYMPHNODE PARASITES
NEMATODA Order: Filariata

BRUGIA MALAYI / WUCHERERIA BANCROFTI

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Brugia malayi /Wuchereria bancrofti: life cycle.

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Brugia malayi /Wuchereria bancrofti: B.malayi is transmitted
by mosquitoes of the genus Mansonia, Anopheles and Aedes.
W.bancrofti is transmitted by mosquitoes of the genus Culex, Anopheles and Aedes.
Close-up of mosquitoes on human skin.

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Lymphatic filariases have a wide geographic distribution.
W.bancrofti and B.malayi infect some 128 milion people,
and about 43 milion have symptoms.
Lymphatic filariases have a wide geographic distribution.
B.malayi infection is endemic in Asia
(China, Corea, India, Indonesia, Malaysia, Philippines, Sri Lanka).
B.timori infection occurs in Indonesia (islands of Alor, Flores, Timor).
W.bancrofti has a larger distribution : Asia
(China, India, Indonesia, Japan, Malaysia, Philippines, South-East Asia,
Sri Lanka, Tropical Africa, Central and South America, Pacific Islands.

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Brugia malayi: microfilariae measure 270 by 8 µm, have a sheath
and a tail with terminal constriction,
elongated nuclei and absence of nuclei in the cephalic space.
They have nocturnal periodicity.
(Wet mount preparation).

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Brugia malayi: The microfilariae are sheathed and can be distinguished
from W.bancrofti for size (275-320x7,5-10), location of nuclei and tail nuclei.
(Fresh examination, particular of the caudal space).

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Brugia malayi: detail of the cephalic space.
Microfilariae are usually nocturnally periodic but sub-periodic strains
of B.malayi and W.bancrofti are observed.
(wet mount, detail of the cephalic space of B.malayi microfilaria).

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bm6: Brugia malayi: identification of microfilariae 
in stained smear is possible by observation of the stained sheath 
(W.bancrofti sheath does not stain). 

wb6: Microfilaria of Wuchereria bancrofti (Giemsa stain, x 400)

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Brugia malayi: the tail is tapered and present a constriction.
The last two nuclei are divided by the constriction. The sheath stains pink.
(Caudal space of B.malayi, Giemsa stain).

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Brugia malayi: the cephalic space is longer than broad
(in W.bancrofti is as long as broad).
(Detail of the cephalic space of B.malayi microfilaria, Giemsa stain).

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bm9:  Lymphatic filariasis: adults of B.malayi and W.bancrofti live
in the lymphatic vessels and lymphnodes where they cause dilatation,
inflammatory infiltrates and, at last, blockage of the lymphatic circulation.
Adenolymphangitis, orchitis, epididimitis associated with fever are
the commonest manifestation of the acute stage of the infection;
eosinophilia is frequent at this stage.
Lymphoedema particularly of the legs and scrotum,
hydrocoeles and chyluria are the result of the progression of the disease;
genital manifestations are frequent in W.bancrofti infections
while they are rare during B.malayi infections.
Lymphatic filariasis: elephantiasis of scrotum. 

wb9: Tanzanian with elephantiasis due to W.bancrofti. 
wb9a: Another Tanzanian patient with elephantiasis due to W.bancrofti. 
wb9b: Early hydrocoel in a Tanzanian man with W.bancrofti infection

Ramaswamy Lymfil_1	Ramaswamy Lymfil_2	Ramaswamy Lymfil_3

Lymphatic filariasis: adult worms in lymph node section of filarial lymphadenitis.

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bm10: Lymphatic filariasis: elephantiasis is the last consequence
of the swelling of limbs and scrotum.
Diethylcarbamazine (DEC), ivermectine and albendazole used
alone or in combination are the drugs of choice.
Elephantiasis of the limbs. 

wb10: Thai patient with elephantiasis of leg due to W.bancrofti or Brugia malayi. 

wb10a: Second Thai patient with elephantiasis due to lymphatic filariasis.