Filaria Nematodes Flashcards
The second leading cause of permanent and long term disability affecting both physical and psychological aspects of the victim
Lymphatic Filariasis
*One of the most debilitating diseases plaguing many tropical countries
Give the lymphatic filarial worms
Wuchereria bancrofti
Brugia malayi
* Brugia timori
Appearance of microfilariae
Graceful, minute snake-like appearance
True / False:
Adult females of B. malayi and W. bancrofti are distinguishable from each other
False. B. malayi and W. bancrofti adult females are indistinguishable from each other
*They can be distinguished through their microfilaria
Mosquito vectors of W. bancrofti
Aedes - in Pacific region
Culex - in Urban areas
Anopheles - Rural areas
The main vector of W. bancrofti and Malaria in the Philippines
Anopheles minimus var. flavirostris
Vector of B. malayi in the Philippines
Mansonia bonnae - in freshwater swamps
Mansonia uniformis - in ricefields
- Aedes, Anopheles
- Coquillettida
The infective stage of filaria to the mosquito & humans
Mosquitos: Microfilariae
Humans: L3 larva
Characteristic uterus of W. bancrofti and B. malayi females
Double-barrel uterus
Clinical spectrum of lymphatic filariasis
- ADLA (Acute dermatolymphangioadenitis)
- ADL (Adenolymphangitis)
- AFL (Acute filarial lymphangitis ) –> palpable cord
- Lymphaedema & Elephantiasis
- Genitourinary lesions (hydrocele) –> enlargement of testes and milky urine
- Tropical pulmonary eosinophila
Brugia malayi can selectively induce _ lymphocyte apoptosis which may contribute to immune unresponsiveness to filariasis
CD4+ lymphocytes
Endemic normals
Patients who harbor the parasite antigen instead of the microfilaria
The most common manifestation of Lymphatic filariasis
ADLA (Acute dermatolymphangioadenitis)
Bacteria most frequently associated with ADLA
Group A streptococcus
Expatriate syndrome
Individuals who grew outside the endemic regions of filarial parasites then migrated to it (char. by immune hyper-responsiveness)
Dreyer’s staging for chronic lymphedema
1- Reversible swelling when lying in bed 2- Irreversible swelling 3- Shallow skin folds 4- Knobs 5-Deep skin folds 6-Mossy lesions 7- Cannot perform daily tasks
Wolbachia
Produced by dying filarial worms
Time of collecting the sample for the thick blood smear to test lymphatic filariasis
Between 8pm-4am
*Due to the nocturnal periodicity of W. bancrofti
In cases of low detection of microfilariae, this concentration test may be used
Knott’s method
Cephalic space of W. bancrofti vs. Brugia malayi
Wuchereria: 1:1
Brugia : 1:2
The gold standard for the detection of lymphatic filariasis
CFA (Circulating filarial antigens)
* DEC = drug of choice for lymphatic filariasis
Meyer’s Kouwenar Syndrome
Presence of microfilaria in the spleen, liver, and lymph nodes
Weingarten’s Syndrome / Typical Pulmonary Eosinophilia
Presence of paroxysmal nocturnal cough, hypereosinophilia and lung impairment
The definitive host of W. bancrofti & Brugia malayi
Humans
Onchocerca volvulus is otherwise known as
River blindness worm
Vector for Onchocerca
Simulium spp. (Buffalo gnat or the black fly)
Clinical manifestations for O. volvulus
- Lizard/leopard skin
- Hanging groin
- Sowda
Responsible for Calabar/ Fugitive swelling
Loa loa
Differece in elephantiasis between B. malayi and W. bancrofti
W. bancrofti - lower extremeties
B. malayi - upper extremeties
Disease caused by O. volvulus
River blindness
Mode of transmission for all filarial worms
Bite of an infected arthropod
Lab diagnosis for filarial worms
- Giemsa-stained smear
2. Knott’s concentration technique
Loa loa is also known as _
Eye worm
Onchocerca volvulus is otherwise known as
Blinding worm
Vectors of Loa loa
Mango fly, fruit fly, chrysops
Vectors of Mansonella
Cullicoides / Midge
Mansonella streptocerca characteristic filarial worm
Sheperd’s crook
Dog heartworm
Dirofilaria immitis
* produces coin lesions in lungs
