Brugia malayi

Jump to navigation Jump to search
Brugia malayi
B. malayi, blood smear, Giemsa stain.
B. malayi, blood smear, Giemsa stain.
Scientific classification
Kingdom: Animalia
Phylum: Nematoda
Class: Secernentea
Order: Spirurida
Family: Filariidae
Genus: Brugia
Species: B. malayi
Binomial name
Brugia malayi
Brug 1927
This page is about microbiologic aspects of the organism(s).  For clinical aspects of the disease, see Filariasis.

WikiDoc Resources for Brugia malayi

Articles

Most recent articles on Brugia malayi

Most cited articles on Brugia malayi

Review articles on Brugia malayi

Articles on Brugia malayi in N Eng J Med, Lancet, BMJ

Media

Powerpoint slides on Brugia malayi

Images of Brugia malayi

Photos of Brugia malayi

Podcasts & MP3s on Brugia malayi

Videos on Brugia malayi

Evidence Based Medicine

Cochrane Collaboration on Brugia malayi

Bandolier on Brugia malayi

TRIP on Brugia malayi

Clinical Trials

Ongoing Trials on Brugia malayi at Clinical Trials.gov

Trial results on Brugia malayi

Clinical Trials on Brugia malayi at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Brugia malayi

NICE Guidance on Brugia malayi

NHS PRODIGY Guidance

FDA on Brugia malayi

CDC on Brugia malayi

Books

Books on Brugia malayi

News

Brugia malayi in the news

Be alerted to news on Brugia malayi

News trends on Brugia malayi

Commentary

Blogs on Brugia malayi

Definitions

Definitions of Brugia malayi

Patient Resources / Community

Patient resources on Brugia malayi

Discussion groups on Brugia malayi

Patient Handouts on Brugia malayi

Directions to Hospitals Treating Brugia malayi

Risk calculators and risk factors for Brugia malayi

Healthcare Provider Resources

Symptoms of Brugia malayi

Causes & Risk Factors for Brugia malayi

Diagnostic studies for Brugia malayi

Treatment of Brugia malayi

Continuing Medical Education (CME)

CME Programs on Brugia malayi

International

Brugia malayi en Espanol

Brugia malayi en Francais

Business

Brugia malayi in the Marketplace

Patents on Brugia malayi

Experimental / Informatics

List of terms related to Brugia malayi

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]

Overview

Brugia malayi is a filarial roundworm which causes filariasis in humans.[1] Identified by Lichtenstein and named by Brug in 1927 as distinct from Wuchereria bancrofti, they called it Filaria malayi. In 1958 the separate genus Brugia was proposed by Buckley, and Filaria malayi became known as Brugia malayi.

B. malayi is limited to tropical regions of Asia.

Life cycle

The life cycle of Brugia malayi.

Infective larvae are transmitted by infected biting arthropods during a blood meal. The larvae migrate to the appropriate site of the host's body, where they develop into microfilariae-producing adults. The adults dwell in various human tissues where they can live for several years. The agents of lymphatic filariasis reside in lymphatic vessels and lymph nodes. B. malayi dwells particularly in the lymphatics, as with Wuchereria bancrofti. The female worms produce microfilariae which circulate in the blood.

The microfilariae infect mosquitoes. Inside the mosquito, the microfilariae develop in 1 to 2 weeks into infective filariform (third-stage) larvae. During a subsequent blood meal by the insect, the larvae infect the vertebrate host. They migrate to the lymphatics, where they develop into adults, a slow process that can require up to 18 months.

Recently B. malayi was found to contain an endosymbiotic bacterium, Wolbachia, in all life stages.[2] The genome sequence of this bacterium was determined at New England Biolabs. Experimental results indicate that the Wolbachia can be killed by treatment of the human host with doxycycline. Nematodes cured of the Wolbachia are sterile and have increased morbidity.

Laboratory diagnosis

Identification of microfilariae by microscopic examination is the most practical diagnostic procedure.

Examination of blood samples will allow identification of microfilariae of Brugia malayi. It is important to time the blood collection with the known periodicity of the microfilariae. The blood sample can be a thick smear, stained with Giemsa or hematoxylin and eosin. For increased sensitivity, concentration techniques can be used. These include centrifugation of the blood sample lyzed in 2% formalin (Knott's technique), or filtration through a Nucleopore membrane.

Antigen detection using an immunoassay for circulating filarial antigens constitutes a useful diagnostic approach, because microfilaremia can be low and variable. Molecular diagnosis using polymerase chain reaction is also possible.

Identification of adult worms is possible from tissue samples collected during nodulectomies (onchocerciasis), or during subcutaneous biopsies or worm removal from the eye (loiasis).

Genome deciphered

On September 20, 2007, scientists mapped the genome or genetic content of Brugia malayi, worm which cause elephantiasis (lymphatic filariasis). Figuring out the content of the genes might lead to development of new drugs and vaccines.[3]

References

  1. Cross JH (1996). Filarial Nematodes. In: Baron's Medical Microbiology (Baron S et al, eds.) (4th ed. ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
  2. Taylor MJ (2002). "A new insight into the pathogenesis of filarial disease". Curr Mol Med. 2 (3): 299–302. PMID 12041732.
  3. Reuters, Genome deciphered for elephantiasis-causing worm