» :See special page for Filariasis in domestic animals Filariasis (Philariasis) is a parasitic and infectious tropical disease, that's caused by thread-like filarial nematode worms in the superfamily Filarioidea, also known as "filariae". There are 9 known filarial nematodes which use humans as the definitive host. These are divided into 3 groups according to the niche within the body that they occupy: Lymphatic Filariasis, Subcutaneous Filariasis, and Serous Cavity Filariasis. Lymphatic Filari… (More on Filariasis)