Nematode Infections Flashcards
cutaneous larva migrant caused by
aka
ancylohstoma brazilians and canines
aka creeping eruption
epi of cutaneous larva migrant
ancylohstoma brazilians and canin in dogs and cats (definitive hosts)
worldwide
life cycle of ancylostoma
adult worms live in cats and dogs
eggs shed in feces
larva hatch and form filariform larvae
these enter skin of humans bc they think we are cats/ dogs
which life cycle stage infects humans in ancylostoma>
filariform larvae
path ancylostoma
patients develop serpiginous tunners– piratic reddish, the tunnels advance many cm in say
hypersensitive ones develop vesicles and bullae at site of infection
dx cutaneous larva migrant
finding larva in tissue biopsy from serpiginous tract
tx cutaneous larva migrant
albendazole
if untx larva dies
but it wanders making more lesions
visceral larva migrans by>
definitive hosts
toxcara canis and cati (roundworms)
dogs and cats - also transmitted thru puppy placenta
how is visceral larva migrant transmitted
toxcara
fecal oral route from animal to humans- unwashed vessels, or eating raw infected tissue of chickens sheep or cattle
life cycle of toxcara
adult worms ONLY in dogs and cats- eggs are released in poopy
eges incubate and are eaten by dogs or cats so enter blood stream and go to lungs
coughed up and swallowed
we eat infection eggs
human infection with toxcara
we eat infected eggs and they enter blood stream but DON’T develop into adult worms (we are accidental hosts )
path of visceral larva migrans (toxcara)
migrating larva produce inflammation hyper eosinophilia rashes fevers immune responses
the damage depends on number of eggs, migration route of larva
s/s of visceral larva migrans
fever cough pneumonitis hepatomegaly edema retinal granulomas
dx visceral larva migrant
clinical symptoms
exposure
or finding larvae
tx visceral larva migrant
ivermectin
dirofilariasis caused by?
definitive host
intermediate host
accidental
dirofilaria immitis (dog heart worms)
def host- doggies intermediate/ vector - mosquito accidntal- humans
life cycle dirofilariasis
adult worms live in hearts of doggos
microlifaria released into blood stream– picked up by mosquitos
in dogs the larva develop into adult worms
in humans they stay in sub q- DON’T DEVELOP INTO ADULT WORMS
Path of dirofilariasis
microfilaria are trapped in skin or lung tissues– and produce allergic reactions resulting in subQ nodules infants and accesses
s/s dirofilariasis
coin shaped lesions* in skin lungs
lungs- coughing chest pain and eosinophilia
dx dirofilariasis
clinical symptoms, locating coin shaped lesions
finding larva in tissue
tx dirofilariasis
sx removal?
dracunculiasis caused by?
aka
dracunculus mediensis
guinea worm
epi dracunculiasis
definitive host
intermediate host
found in Africa and Asia
human only reservoir / def host
interm- water flea
life cycle dracunculiasis
adult worms live in CT of humans
released when they come in contact with water (dirty water)
water flea ingest larvae– from infective form
they ingest dirty water and penetrate the mucosa of the stomach into abdominal cavity to under the skin
path dracunculiasis
adult worms release metabolites into CT
produces allergic reaction*
causes inflammatory response – and leukocytes surround the worm
ss dracunculiasis
asymptomatic for year
painful blisters, urticaria nausea and booming
ulcers become infected with secondary bacteria
dx dracunculiasis
adult female worms extending from subQ releasing larva into water
tx dracunculiasis
antibiotics to tx infectoin
stick to slowly wrap the worm!!!!
loiasis caused by
loa loa
epi of loa loa
definitive host
intermediate host
equatorial africa
human definitive host
intermediate host- deer fly
life cycle loa loa
adult worms live in humans, releasing microfilaria into blood streem
deer fly leaps up blood and grabs it— develops into filariform larvae
which then are transmitted to human and go back to sub q
infectious to human loa loa
Filariform larvae
path loa loa
adult worms are in sub q tissues
release metabolites that produce inflammatory rxn
found under conjunctiva of EYE - can disappear within minutes
ss loa loa
fever itchy swellings on body
erythema
urticaria
subcutaneous Calabar swelling*
adult worms- crawling sensation in eye
dx loa loa
Calabar* swellings = microfilarria in blood smears and worms in blodo
tx loa loa
diethylcarbamaxine tx and prophylaxis
but won’t change damage done
onchocerciasis caused by?
aka
onchocerca volvulus
aka river blindness
epi onchocerciasis
location
- definitive host
- intermediate host/ vector
Equatorial africa, south central america
def host- humans and monkeys
intermediate host- black flies
life cycle onchocerciasis
adult worms live in sub q tissues of humans and they release microfilariae
black flies pick up during blood meal and the larva develop into filariform larva-
and infecte again when the black fly bites another human
path onchocerciasis
incubation- years
adult worms produce fibroblastic rxn in subcutaneous tissues
microfilaria can die and become trapped in granuloma in eye
dx onchocerciasis
microfilaria seen in nodule biopsies
Mazzoti test- oral dose of diethyl carbamazine produces papular erythematous rxn in affected skin and conjunctival swelling
tx onchocerciasis
diethylcarbamaxine
