Filariasis treatment. Nurse placing a tablet of the drug albendazole, used to treat lymphatic filariasis, into a boy's mouth using a spoon. His mother is holding a glass of water. Lymphatic filariasis is a disease caused by parasitic worms transmitted by mosquitoes when they feed. The worms cause the body's lymph vessels to become blocked. Lymph fluid then accumulates in the surrounding tissues (oedema). Repeated infection may result in elephantiasis as the affected part of the body, commonly a limb, becomes massively enlarged. This is part of a mass drug administration that took place on Monono Island, Samoa, in 1999.