BRUGIA MALAYI
MORPHOLOGY
Adult Brugia malayi are long and slender with a smooth cuticle.
The head is slightly swollen and has two circles of well-defined papillae. Female :8 cm long by 0.3 mm wide. Male: 2 cm long by 0.1 mm wide.
Microfilariae are found in the peripheral blood. Adult worm
LIFE CYCLE
In a human host, An infected mosquito injects third-stage filarial larvae onto the skin of the human host during a blood meal, where they penetrate the bite wound.
They form in adults and are commonly found in the lymphatic system. Female worms are 80 to 100 mm long and 0.24 to 0.30 mm in diameter, while males are 40 mm long and 100 mm wide.
Adults produce microfilariae that are sheathed and have a nocturnal periodicity, measuring 244 to 296 m by 7.5 to 10 m.
The microfilariae migrate into lymph and blood channels moving actively through lymph and blood.
In mosquito host, mosquito ingests the microfilariae during a blood meal.
After ingestion, the microfilariae lose their sheaths and some of them work their way through the wall of the proventriculus and cardiac portion of the mosquito's midgut and reach the thoracic muscles.
microfilariae develop into first-stage larvae and subsequently into third-stage infective larvae.
The third-stage infective larvae migrate through the hemocoel to the mosquito's prosbocis and can infect another human when the mosquito takes a blood meal.
PATHOGENESIS
LAB DIAGNOSIS
Examination of fresh Giemsa-stained blood
Knott’s technique
Serologic test
There is NO INVOLVEMENT of male genitalia.
B. malayi causes brugian filariasis
Pathology - Adults live in lymphatic vessels of the arms and legs and cause elephantiasis in these regions