Female worms are ovoviviparous and can produce thousands of juveniles known as microfilariae, in infected humans. These are ingested by mosquitoes when they bite. The ingested microfilaria mature and eventually migrate to the insect proboscis from where they get injected into the human skin.

The vast majority of infected people are asymptomatic, but virtually all of them suffer from damages to the lymphatic system and the kidneys, and from an altered body's immune system. People infected with filariasis who have microfilaraemia or a positive antigen test should receive antifilarial drug treatment to eliminate microfilariae.

Lymphatic filariasis is a disease caused by microscopic parasitic worms. Most people have no symptoms, but in others it can cause arms, legs, breasts, or genitals to swell. Overview Lymphatic filariasis, sometimes called LF, is a disease caused by an infection with thread-like parasitic worms.

Microfilariae develop in the mosquitoes. The transmission to dogs or other hosts including humans occurs through mosquito bite during subsequent blood meal. Humans may be infected as aberrant (accidental) hosts, mainly by D. repens and D. immitis. D. repens usually resides subcutaneously, while D. immitis frequently ends up in the human lung.