Lymphatic filariasis drugs albendazole and (top) diethylcarbamazine (DEC). 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. Photographed at a drug distribution point in Samoa in 1999.