Filariasis

Filariasis is a parasitical and infectious tropical disease, caused by the thread-like parasitic filiria worms, Wuchereria bancrofti, Brugia malayi, and B. timori, all transmitted by mosquitoes. It is extremely rare in Western countries.

The form of Filariasis most common is elephantitis (swelling in the genitals or thighs), which was the first disease discovered to be transmitted by insects. Elephantitis is caused when the parasites lodge in the lymphatic system.

In 1866, Otto Wecherer demonstrated the presence of filiria, or filiria larva, in urine. In 1871, Timoth Lewis discovered the presence of microfilaria in peripheral blood; later, in 1876, Joseph Bancroft discovered the adult form. Finally in 1878, Patrick Manson observed the development of Wechereria bancrofti in mosquitos.

Filariasis is endemic in tropical regions of Asia, Africa, Central and South America

Elephantitis affects above all the lower extremities, whereas ears, mucus membranes, and amputation stumps are rarely effected; however, it depends on the species of filaria. Wechereria bancrofti can affect the legs, arms, vuvla, breasts, while Brugia timori rarely affects the genitals.