Brugia Malayi Morphology Quiz

Dracunculus Medinensis (Guinea Worm)

• Infection occurs through ingestion of infected copepods through contaminated water, unfiltered water, or by eating fish or frogs that have ingested infected copepods.
• Pathogenesis: causes allergic reaction, 2nd bacterial infection, and lays eggs that cause blisters.
• Diagnosis: observing infected ulcers and induced rupture of the infected ulcers by immersing in cool water.
• Treatment: no medicine, total worm removal.

Filarial Nematodes (Lymphatics)

Wuchereria Bancrofti

• Common name: Bancroft's filarial worm.
• Causes: Bancroftian filariasis.
• Habitat: Lower lymphatics.
• Vector: Culex, Anopheles, Aedes, and Mansonia mosquitoes.
• Mode of transmission: skin inoculation.
• Specimen: Blood.
• Periodicity: Nocturnal periodicity (8PM- 4AM).
• Infective stage: L3.
• Morphology: Adult creamy white, long, and filiform in shape. Male: 20 to 40 mm in length, Female: 80 to 100 mm.
• Microfilaria (L1/L3): "graceful appearance", motile, along with RBCs, minute snake-like organisms, 270 to 290 µm, enclosed in a hyaline sheath.

Brugia Malayi

• Common name: Malayan Filaria.
• Causes: Malayan filariasis.
• Habitat: Upper lymphatics.
• Vector: Mansonia mosquitoes.
• Mode of transmission: skin inoculation.
• Specimen: Blood.
• Periodicity: Nocturnal sub-periodicity.
• Infective stage: L3.
• Morphology: Adult creamy white, long, and filiform in shape. Male: 20 to 40 mm in length, Female: 80 to 100 mm.
• Microfilaria (L1/L3): "kinky appearance", 111 to 230 µm, enclosed in a hyaline sheath, dark-staining nuclei with two nuclei at the tip of the tail.

Pathogenesis and Clinical Manifestations of Lymphatic Filariasis

• Clinical spectrum: asymptomatic microfilaremia, acute dermatolymphangioadenitis (ADLA), acute filarial lymphangitis (AFL), lymphedema (elephantiasis), and genitourinary lesions.

Onchocerciasis

• Causes: eye and skin disease, severe itching, disfiguring skin conditions, and visual impairment, including permanent blindness.
• Manifestations: hanging groin, leopard skin, river blindness.
• Treatment: ivermectin, surgery.
• Prevention: personal protection, destruction of vector breeding areas.
• Epidemiology: distributed primarily in equatorial Africa and Central America.

Other Filarial Parasites (Mansonella spp)

M. Ozzardi

• Common name: Ozzard's Filaria, New World filaria.
• Causes: non-pathogenic.
• Habitat: Body cavities.
• Vector: Culicoides fly (sucking midge), Simulium black fly.
• Mode of transmission: skin inoculation.
• Specimen: Blood.
• Periodicity: Non-periodic.
• Infective stage: L3.
• Microfilaria: unsheathed, arrangement of nuclei in tail is numerous and do not extend to tip of tail.

M. Perstans

• Common name: Perstans filaria.
• Causes: Calabar-like swelling, non-pathogenic.
• Habitat: Body cavities.
• Vector: Culicoides fly (sucking midge), Simulium black fly.
• Mode of transmission: skin inoculation.
• Specimen: Blood.
• Periodicity: Non-periodic.
• Infective stage: L3.
• Microfilaria: unsheathed, arrangement of nuclei in tail is numerous and extends to tip of tail, anterior or tail end is rounded and blunt.