Filaria Flashcards
true or false: filaria is a roundworm
true it is a nematode
where do adult filaria live
in body cavities, lymphatics and subvutaneous tissues
microfilaria (embyos) live where
live in blood or dermis
what are the vectors of filaria
they require an insect or custacean
how long is the microfilaria
150-350 u long
how long is the filaria
2-12cm long and 4-10u wide
which are the parasites of filaria that live in the blood
-wucheria bancrofti
-brugia malayi
-brugia timori
-loa loa
-mansonella ozzardi
-mansonella perstans
what is the geographic distribution, vector and tyoe of disease of wucheria bancrofti
-all tropics
-mosquito
-lymphatic filiarisis
what is the geographic distribution, vector and tyoe of disease of brugia malayi
-south east asia
-mosquito
-lymphatic filiarisis
what is the geographic distribution, vector and tyoe of disease of brugia timori
-timor, indonesia
-mosquito
-lymphatic filiaisis
what is the geographic distribution, vector and tyoe of disease of loa loa
-african forest areas
-deer fly
-eye worm
what is the geographic distribution, vector and tyoe of disease of mansonella ozzardi
-new world caribbean
-midge
-eye worm
what is the geographic distribution, vector and tyoe of disease of mansonella perstans
-all tropics
-midge
-eye worm
what are the filaria that live in the blood
-onchocerca volvulus
what is the geographic distribution, vector and tyoe of disease of onchocerca volvutus
-africa, yemen, central and south america
-black fly
-river blindness
Lymphatic group: filaria
Wuchereria bancrofti
Brugia malayi
Brugia timori
cutaneous group filaria
Loa loa
Onchocerca volvulus
body cavity group filaria
Mansonella persitans
Mansonella ozzardi
true or false: wucheria bancrofti cause elephantiasis
yeah aka lymphatic filariasis
what is the lenght if male and female wucheria
Males: Length 4-5 cm
Females: Length 6-10 cm
true or false: microfilaria in wucheria had a sheath in the tail
truewhat
what is the host of wucheria
humans
what is the lenght of brugia
Males: 1-2 cm long
Females: 8-10 cm long
what is the vector of wuheria
Mosquito (many species)
eg. Anopheles, Aedes, Culex
true or false: brugia has a sheath in the tail
true
what is the definitive host of brugia
humans and monkeys
what is the vector of brugia
mosquitoes, many species such as aedes and culex
what is the global distribution of lymphatic filariasis
33% in India
33% in Africa
33% in Asia,Pacific,Americas
how many people are infected with filariasis
120 million
-90% develop bancroftian filariasis
how many people develop the pathology of bancroftian filariasis
44 million
what are the 4 phases of wucheria bancrofti
-asymptomatic
-inflammatory
-obstructive
-tropical pulmonary eosinophilia
inflammatory wucheria
- lymphangitis - arms 25%
- legs 11%
- epididymitis, funiculitis 42%
- ‘filarial fever’
- orchitis
- filarial abscess
obstructive wucheris
-elephantiasis
-chyluria
-hydrocele
true or false: the incubation phase in filaria is mostly asymptomatic
true
it is upuntil there is the appearance of microfilaria
what causes the acute or inflammatory phase
females reach maturity and release microfilaria
what happens during the acute or inflammatory phase of filariasis
- Intense lymphatic inflammation, chills, fever, and toxemia.
- Swollen lymph nodes. lymphadenitis, orchitis, hydrocele, epidymitis
what causes the obstructive phase of filariasis
-blockage of lymphatic ducts
-inflammation of lymph nodes and walls
what happens in the obstructive phase in filariasis
- Lymph node backs up and passes into surrounding tissue
- followed by fibrosis, chyluria, elephantiasis
what is chylocele
- white lymph fluid in the cavity of the Tunica vaginalis testis
- caused by rupture of dilated lymp
what is acute filarial lumphangitis
-afl
-caused by the death of the adult worm
what is hydrocele
- collection of serous fluid in the cavity of the Tunica vaginalis testis
- caused by lymphatic dysfunction
what is chyluria
- Milky fluid due to the presence of white lymph from a ruptured dilated lymphatic vessel in the excretory urinary tract
what are the factors of the pathogenesis of lymphatic filarial disease
-inflammatory/immune mediators
-other factors
-death of parasite/wolbachia
-secundary bacterial/fungal infections
what is a sign of an acute attack of filariasis
skin is tense and red
what is the diagnosis for filaria
- presence of microfilariae
- finger prick (blood smears)
- skin snips
- circulating filarial antigen (CFA) (Wuchereria)
- IgG4 ELISA tropical eosinophilia syndrome
- Antifilarial antibodies (IgG and IgE)
- IgG4 to recombinant antigen
what are the treatment for filariasis
-diethylcarbamazine aka dec
-albendazole
-vermectin
- Diethylcarbamazine (DEC)
- Sensitizes microfilaria to phagocytosis
- Optimal dose does not clear all the microfilaria and only a proportion of adult worms are killed
- 70-80% reduction in transmission using DEC
Albendazole
-for wucheria
-* It acts by inhibiting the polymerization of beta-tubulin and microtubule formation
Treatment
* Specific for parasite tubulin
Ivermectin
*Acts by hyperpolarization of Glutamate-sensitive channels. Glu-Cl receptors (specific to parasite receptors) and chloride channel permeability
* 90% reduction in transmission using Ivermectin
* Up to 99% reduction in transmission using DEC + Ivermectin
Chemotherapeutic control: of wucheria: the 3 main objective
- Reduced mortality
- Reduced transmission
- Interrupt transmission (vector control)
true or false: vector control is hard for filaria
true
Global Programme to Eliminate Lymphatic Filariasis (WHO): objectives
- To interrupt the transmission of infection
- single dose; two-drug regimen
- to alleviate and prevent suffering and disability
- secondary infections
international elimination program for lymphatic filariasis, it relies on what?
On breaking transmission through yearly mass treatments of entire communities with the anthelmintic drugs Albendazole (Glaxo SmithKline ) in combination with Diethylcarbamazine
or Ivermectin (Merck Co.)
Filarial molecules activate both….
pro inflammatory and anti inflammatory reactions
which tyoe of response does filariasis promotes
th2
true or false: in asymptomatic microfilaria people, there were higher blocking levels of igg compaired to those that have the chronic lymphatic pathology
true
igg1 and igg4 significated the difference between what groups
the groups that had:
-microfilaria but no clinical disease: had more igg4
-and those that have chronic lymphatic pathology had less: igg1
-
IgG4 levels correlate with blocking activity in …… serum
those that have microfilaria in blood but no clinical presentation
Depletion of IgG4 leads to reduction in blocking
activity in MF sera by ….
53-81%
Lymphatic Filariasis was targeted for elimination in …
1997
we still have it lol
but our treatments work well
there is barely any transmission: 1% for moderate and 5% for high rate
what are the other named of loa loa
“Loiasis”
“eye worm”
“Calabar Swellings
what does onchocerca volvulus cause
river blindness
how many people are infected with loa loa
30 million
how many people are affected by river blindness
- 270,000 with blindness
-500,000 with severe visual impairment
how many microfilaria does onchocerca sheds per day
1900
signs of onchocerca infection
-skin lesions
-skin nodules
-eye lesions
what are the skin lesions form loaloa
edema
pruritus
papules
scab-like eruptions
altered pigmentation
lichenification
what are the eye lesions fue to loaloa
punctate keratitis
pannus formation
corneal fibrosis
glaucoma
optic atrophy
loaloa pathology is associated with
Is associated with a long-standing host inflammatory response to proteins from live, dead and/or dying microfilaria
inflammatory response of loaloa is mediated by what
eosinophils
When O. volvulus invades the cornea it causes inflammation of the…
sclera, cornea, iris and retina
fibrosis leads to blindness ….
7-9 years later
Dermatitis
Itching lead to secondary bacterial infection followed by thickening, discoloration and
cracking of the skin: Lichenification
what is pannus formation
a slow progressive degenerative disease of the cornea
in burkina faso: about 46% of infected men and 35% of women were blind due to …..
onchocercasis
which country has the highest number of blind in the world due to onchocercasis
chad
diagnosis of loa loa
-microfilaris: skin snip
-if negative the mazzotti test is used: DEC patch=itching
* Detection of filarial antigen
* Detection of anti-filarial antibodies –O. volvulus IgG4
* Complete blood cell count – eosinophilia
treatment for loaloa
-nodulectomy:
-chemotherapy
chemo therapy for loaloa
-Diethylcarbamazine is more toxic
-Ivermectin:
Well-tolerated
Action on microfilariae
Reduces fecundity in adult
female worms