malayi

Brugia malayi is a parasitic nematode and one of the causative agents of human lymphatic filariasis. It is a filarial worm transmitted by mosquitoes that inhabits the lymphatic system of the human host, where adult worms mate and produce microfilariae that circulate in the bloodstream.

Geographic range includes parts of Southeast Asia and the western Pacific, such as Indonesia, Malaysia, Thailand, Vietnam, the Philippines, and southern China. Vectors include several mosquito species, notably Mansonia and Anopheles in different regions; zoonotic reservoirs may occur in some areas.

Life cycle: In humans, adult worms live in lymphatics; females release microfilariae that circulate and exhibit nocturnal periodicity. When a mosquito feeds, it ingests microfilariae, which develop into infective L3 larvae inside the mosquito and are transmitted to another person during a future bite. The larvae mature into adults weeks to months after transmission.

Clinical features: Chronic lymphatic damage can cause lymphedema and elephantiasis; serous hydrocele may occur in males. Some individuals experience recurrent fever episodes due to inflammatory responses; tropical pulmonary eosinophilia can occur in a minority of patients.

Diagnosis: Microfilariae can be detected in peripheral blood using nocturnal blood sampling or antigen-based tests. Imaging and ultrasound may reveal dilated lymphatics or moving worms in accessible sites.

Treatment and control: Antiparasitic regimens typically include diethylcarbamazine (DEC) or ivermectin plus albendazole; management of complications includes hygiene and compression. Public health programs use mass drug administration to reduce transmission and work toward elimination.

Taxonomy and nomenclature: Brugia malayi is in the family Filariidae, phylum Nematoda. The species name reflects its initial description in the Malay region; closely related species include Brugia timori and Wuchereria bancrofti.