_Adults W. bancrofti in the lymphatics of human host.
_Adult W. bancrofti releases sheathed microfilariae (early larval forms) into the blood stream
_Mosquito feeds on microfilariae infested blood.
_In the mosquito microfilariae shed the sheath, migrate into midgut and then to thoracic muscles.
_ Microfilariae develop into L1 larvae then L3 larvae.
_L3 larvae migrate into mosquito proboscis and are innoculated into human host during the feeding of mosquito.
There are 3 phases of W. Bancrofti infection each with specific symptoms and signs:
_Characterized by high microfilaremia infection
_Barely any symptom of disease.
_It can occur for years.
_W. Bancrofti in the lymph channels block the flow of the lymph leading to lymphedema.
_Inflammatory responses are elicited by antigens from the female adult worms causing fever and chills
_Painful lymph nodes
_Tender skin of the lymphedematous extremity.
_Tabs Ivermectin 150-200mcg/kg Stat. repeated at 6 and 12 months
_Tabs Diethycarbamazine: 6 mg/kg repeated at 6 and 12 months.
_Massive hydroceles and scrotal elephantiasis are managed surgically. Surgery of limb elephantiasis is often is often less successful requiring multiple procedures and skin grafting.
_W. bancrofti requires the bacteria Wolbachia for survival and embryogenesis hence justifying the use of doxycycline or any other effective antibiotic as adjuvant in the treatment regime for the infestation.
_Some studies have shown that a polytherapy treatment that includes ivermectin with Diethycarbamazine or albendazole can be more effective.
_Prevention is by vector control and mass chemotherapy.