Filariasis
Epidemiology and Etiology:
- Wuchereria
bancrofti
- Brugia malayi
- Lifecycle:
- Larvae transmitted
by mosquitos to human tissues
- Larvae develop
within lymphatic channels into adults
- Adults mate and
release microfilariae into the bloodstream
- Microfilariae can
be picked up by mosquitos to transmit the disease
- Endosymbiotic rickettsia-like
Wolbachia bacteria may be required for nematode development and
reproduction
-
Common sites:
- Inguinal lymphatics
- lungs (tropical
pulmonary eosinophilia)
Gross features:
- lymphedema of
the scrotum, penis, vulva, leg, or arm
- hydrocele
- lymphadenopathy
Histologic features:
- adult
filarial worms in lymphatics or lymph nodes
- may or may not have
surrounding inflammatory response:
- intense
eosinophilia with hemorrhage and fibrin
- granulomas
- Meyers-Kouvenaar
bodies (tropical pulmonary eosinophilia):
- Dead microfilariae
surrounded by stellate, hyaline, eosinophilic precipitates embedded in
small epithelioid granulomas
Immunophenotype:
Marker:
|
Sensitivity:
|
Specificity:
|
|
|
|
Molecular features:
Other features:
- tropical
pulmonary eosinophilia is caused by an IgE hypersensitivity response to
the microfilariae
References: