Lymphatic Filariasis Flashcards
It's an intestinal nematode
Classification of filariasis
- Lymphatic filariasis
- Cutaneous filariasis
- Other. (Blood vessels, connective tissue, or serous membrane)
Periodic and subperiodic rhythm
W. Bancrofti - periodic+subperiodic
B. Malayi - both
B Temori - periodic
Periodic: microfilaria present at specific times of the day (take blood sample at night or do provocative day test by giving diethyl carbamazine)
Periodic: all times of the day.
Life cycle of lymphatic filarial worms
- Blood meal, mosquito drops microfilaria to skin
- Microfilaria to lymphatics (thru bite wounds)
- Mature & mate in lymphatics
- Females are oviparous: produce sheathed microfilaria
- Mfilariae move to blood and lymph channels
- Mosquito picks them up from peripheral blood
- M.f lose sheath in mosquito midgut
- Penetrate midgut muscles
- To thoracic muscles
- Develop to larvae (L1, L2, L3)
- To head hence on mosquito proboscis
Clinical manifestation of lymphatic filarial worms
Asymptomatic filariasis
Symptomatic
∆inflammatory phase
∆obstructive phase
Living adult worms and larvae in lymphatic system causes
•Lymphangitis (inflammation of lymph vessel walls)
Due to: mechanical irritation
Liberation of metabolites
Absorption of toxic products from dying. worms
Bacterial infection
Microfilaria cause lesions in lungs, liver spleen
•Lymphadenitis (inflammation of lymph nodes)
Groin and axilla
Effects of lymphatic obstruction
Lymphangiovarix: dilatation of lymphatics
Lymphangiovarix rupture
Lymphorrhagia: lymphuria, lymphocele, lymph scrotum
Chylorrhagia: chyluria, chylocele, hematochyluria, chylous diarrhea, chylothorax, chylous ascites.
Hyperplasia - skin and CT
Septic Lymphangitis, abscesses and septicemia
Secondary bacterial infections
Other dxs caused by adults
- Elephantiasis - constriction of afferent lymphatics draining a part.
- Hydrocele
- Chyluria
Dxs by microfilaria
- Occult filariasis (meyers-kouwenaar syndrome)
2. Topical pulmonary eosinophilia (eosinophilic lung, weingarten’s syndrome)
Features of occult filariasis
Massive eosinophilia Lymph node enlargement - Lymphadenitis Hepatosplenomegaly Pulmonary symptoms Absence of microfilaremia
Features of topical pulmonary eosinophilia
Low fever
Weight loss
Paroxysmal coughs with scanty (blood stained) sputum
Dyspnea
Splenomegaly
Chest radiography indicates bronchovascular markings or diffuse mottling in the lung fields
Diagnosis of filariasis
Microscopy - blood
Immunodiagnosis - antibody ELISA, Rapid diagnosis test
Molecular techniques eg PCR
Radiology
Treatment
Chemotherapy:
Ivermectin
Diethyl carbamazine
Albendazole
Surgical
Hydrocelectomy
Lymphovenous bypass
Subcutaneous filariasis caused by
Loaloa
O. Volvulus
Mansonella streptocerca
O. Volvulus causes which dx?
Onchocerciasis ( river blindness)
R. Blindness coz
O. Volvulus has obligatory acquatic stage.
(Common in fast flowing streams n rivers). This helps with Breeding of egg
