Filarial Disease Flashcards
What are the 3 types of filariasis infection
Lymphatic
Subcutaneous
Conjunctiva
Main causative agents of lymphatic filariasis
Wuchereria Bancrofti (subtropics) Brugia Malayi (Malaysia)
Vector in B. Malayi
Mansonia mosquito
What is a nematode
Roundworm
Describe the mosquito stages
Mosquito takes up blood meal, ingesting microfilariae in sheathe
Sheathe shed in mosquito, travels to hind gut, migrated to thoracic muscles
L1 to L3 larvae stage
Migrated to head and proboscis
Describe the human stages
Larvae injected as L3 when mansonia mosquito takes blood meal from human
Larvae into skin
Migrate to lymphatic where they mature
Mating
Produce sheathed microfilariae - these migrate to lymph and blood channels
Primary lesion caused by adults blocking lymphatics
How does this predispose a bacterial infection, what does this potentially lead to?
Lymph stasis, bacteria colonise the lymphatics, inflammatory response occurs
Connective tissues proliferates and fibrosis occurs
This blocks lymph drainage
Clinical symptoms
Lymphatic dysfunction later on
Asymptomatic in most stages
Acute case: painful swelling, fever in bacterial infection
Tropical pulmonary Esinophilia
Hyper response to microfilariae in the lung capillaries
Chronic filariasis
Lymphoedema
Renal pathology, lymph/ damaged matter in urine
Secondary infections in skin folds
Diagnosis
Night blood taking, blood film can show species
US
W. Bancrofti biology
No terminal nuclei, faintly stained, sweeping curve appearance
B. Malayi
2 distinct nuclei
Kinky appearance
Clearly pink stained
treatment
Diethylcarbamizine (DEC)
Albendazole against microfilarials
therapy
foot hygiene, bandaging to promote flow
