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Type of filariasis Lymphatic filariasis

Worm species Wucheria bancrofti Brugia malayi, Brugia timori

Vector Culex

Anopheles spp.

Aedes spp.

Mansonia spp.

Clinical features Acute phase (inflammatory filariasis)

Due to sensitization to products of living and dead worms

Suffer from malaise, fever due to acute lymphagitis, lymphadenitis

Males; acute epididumo-orchitis Chronic phase

Lymphedema; grade 1 (pitting edema, reversible with limb elevation), grade 2 (nonpitting edema, irreversible on limb elevation), grade 3 (elephantiasis)

Chyluria; often associated with gross hematuria, reflux of intestinal lymph node into renal lymphatic (LN obstruction below cysterna chili), rupture, chyle flow to urinary system. Urine white (morning), red (later in the day)

Elephantiasis; large irregular folds of skin and subcutaneous tissue, affect limb, breast, scrotum, penis. Result of obstruction of lymph node, thickened with surrounding edema, inflammatory cell reaction. Some associated with phlebitis, capillaries inflammation and trauma by worms.

Hydrocele; scrotal fluid accumulation, due to obstruction in retroperitoneum, not common in bancroftian but common in brugian.

*mainly by adult worms

Diagnosis Blood examination (to look for mf); wet mount prep, stained thick blood film, concentration technique

Sheathed

Smooth body curve

Cephalic space 1:1 ratio

“countable” body nucleus

Sheathed

Kinky body curve

Cephalic space 1:2 ratio

“terminal nucleus”

Serology test; ICT, brugia rapid

Treatment DiEthylcarbamazine Citrate (DEC)

Ivermectin (Mectizan)

Albandazole

Prevention Vector control, protection from vector

Host treatment

Mass control program, education

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Types of filariasis Subcutaneous filariasis

Worm species Onchocerca volvolus Loa loa

Disease Onchocerciasis, River Blindness Loasis, Calabar swelling/ eyeworm

Vector Blackfly, Simulium spp Deerfly, Chysops spp

Clinical features Early infection; asymptomatic

Blackfly bites are painful and may bleed, multiple bites result in urticaria and itching (intense with swelling, hyper pigmentation, diffuse popular eruption and regional lymphadenopathy)

Calabar swelling; focal angiodema located at extremities

Cause is unknown but may represent an immune response to antigenic material where the worm has migrated

Occur one site at a time, may recur sporadically

More common in visitor to an endemic region than local inhabitants

Fatigue and arthralgias not uncommon

Adult worm wander at scrotal skin, spermatic cord, subconjunctival tissue of the eye

Adult worm early visible and do not form nest

Caused by adult worm; onchocercoma (subcutaneous nodule containing adult worm) Flattened, firm, mobile and tender, 3 discrete layer

Outer fibrous layer of granulation and scar tissue

Middle inflammatory cells (eosinophil, plasma cells, foamy macrophages)

Central core, contain adult male and female worms

Caused by micro filarial

Dermatitis; degeneratinf mf at upper half of body.skin pigmentation result in leopard spot, to skin thickening, progress to severe wrinkling. End is fibrosis

Non tender lymphadenopathy, lymphedema and protrusion of superficial nodes (lymph node obstruction from migrating mf)

Eye lesion; penetration by mf. Both portions. Anterior portion lead to punctate keratitis, common in young people and reversible. When chronic inflammation lead to sclerosing keratitis and iridocyclitis result in blindness. Posterior portion, chorioetinitis and optic nerve atrophy may cause blindness

Diagnosis Skin examination (to look mf)

Without sheath

Anterior end; shape of spatula

Blood examination (to look for mf)

Kinky

Posterior end always curl-up towards body

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Posterior; body nucleus not present With sheath

Treatment Drug; ivermectin

Nodulectomy

Drug; DEC

Removal of adult worm from conjunctiva

Prevention Reduction in human fly contact

Treatment

Vector control

Individual control

Education

Avoid the bites of Chrypsops flies

Destruction of Chrypsops flies

Treatment

Mansonella spp.

Species Adult Mf Diagnosis Vector

Mansonella streptocerca Just below the surface of the skin Skin snip Cullicoides midges

Mansonella perstans Serous cavity of the abdomen and chest

Peripheral blood Blood examination

Mansonella azzardi Live in mesenteric and subperitoneal tissue

Peripheral blood

Blood and skin

Cullicoides midges and simulium blackfly

*cause allergic reaction *does not require treatment

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