Brugian filariasis is caused by the parasitic roundworm, Brugia malayi.  The parasite is responsible for around 10% of LF cases [1].  The juvenile stages either exhibit a nocturnal periodicity or subperiodicity, meaning they are only found circulating in peripheral blood and specific times of night or also circulate in small numbers during the days, respectively [2]. This coincides with the biting times of the mosquito vectors. The majority of transmission occurs by Mansonia mosquitoes but in some areas, Anophelines are also responsible [3]. Brugian filariasis is confined to regions of East and South Asia including India, Malaysia and Thailand.


  1. World Health Organisation. Lymphatic Filariasis: Epidemiology. 2019 Available at

  2. Edeson JF, Wilson T. The epidemiology of filariasis due to Wuchereria bancrofti and Brugia malayi. Annual Review of Entomology. 1964 Jan;9(1):245-68.

  3. Dedkhad W, Christensen BM, Bartholomay LC, Joshi D, Hempolchom C, Saeung A. Immune responses of Aedes togoi, Anopheles paraliae and Anopheles lesteri against nocturnally subperiodic Brugia malayi microfilariae during migration from the midgut to the site of development. Parasites & vectors. 2018 Dec;11(1):528.