Helminths - Nematodes Flashcards
most common helminth infection in US
pinworm, enterobius vermicularis (itchy butthole)
manifestation of onchocerciasis
-
Dermal
- microfiliariae traveling in skin destroy elasticity: elephant skin
- depigmentation on shins/top of feet
- papular eruptions, sterile abcesses, subcutaneous nodules
- Ocular: microfiliarie that move into the eye cause blindness(wolbachia bacteria released)
- Lymphatic: lymphadenopathies
enterobius vermicularis transmisison/lifecycle
PINWORM
- sticky eggs get on hand and you eat em (fecal-oral)
- larvae hatch in small intestine; adults form in colon
- gravide females deposit eggs on perianal folds at night time
- itch butt and eat more eggs, or pass in feces to environment to infect others
treatment for ascariasis
albendazole, mebendazole(alt. pyrantel pamoate)
clinical manifestation of hookworm disease
itching @ penetration site
anemia, diarrhea, wt loss, difficulty breathing(lung phase), protein deficient, big heart
leads to physical/mental growth retardation
trichinella spiralis life cycle/transmission
- ingest carnivore that has cysts in muscle(bear, pig)
- de-cyst in stomach; larvae invade small bowel
- adults form; females release larvae
- released larvae encyst striated muscle
clinical manifestation of loiasis
often asymptomatic
calabar swellings = episodic angioedema
subconjunctival migration(crawl across eye….creepy)
treatment for hookworms
albendazole(alt. piperazine, pyrantel pamoate)
ferrous sulfate for anemia
light infections are not treated
toxocara canis/cati life cycle and transmission
humans ingest infective eggs from dog/cat poop
eggs hatch in small intestine, larvae penetrate intestinal wall
disperse to a variety of tissues(esp. liver, brain, eye)
larvae cause severe local reactions
onchocerca volvulus life cycle
L3 introduced by black fly
develop into adults in subcutaneous tissue; reside in nodules
adults make microfiliarie that migrate through skin/lymphatics
treatment for loiasis
antibacterial cream
diethylcarbamazine and ivermectin
treatment for lymphatic filariasis(w. bancrofti, b. malayi)
diethylcarbamazine and ivermectin
clinical manifestation of trichinella spiralis infection
NVD, fatigue, fever @1-2 days
HA, fever, chills, cough, eye swelling, aching joints, muscle pain, itchiness, diarrhea/constipation @2-8 weeks
Heavy infection: trouble coordinating movements; heart/breathing problems
clinical manifestation of **ascariasis **
abdominal pain, flu-like symptoms
coughin wheezing(larvae moving through lungs)
intestinal blockage
ascaris pneumonia(heavy infection); potentially fatal
wucheria bancrofti and brugia malayi are the cause what?
lymphatic filariasis
clinical manifestation of enterobius vermicularis
treatment?
PINWORM
itchy butthole
sleep disturbance, irritability, loss of appetite
treatment: albendazole, pyrantel pamoate
life cycle of loa loa
flies of chrysops spp. transfer L3 during bloodmeal
larvae develop into adutls and sit in subcutaneous tissue
adults make microfilariae(in blood during day, lungs at night)
treatment of onchocerciasis
ivermectin; doxycycline(for the wolbachia)
what are wolbachia?
bacterial parasites living inside nematodes like onchocerca volvulus
thought to be the cause of pathology in blindness caused by o. volvulus
body has hypersensitive reaction to the bacterial antigens and hurts the eye
clinical manifestation of strongyloides stercoralis
Moderate
- Rash @ penetration site
- Coughing wheezing
- Ab pain, nausea, vomiting, alternating diarrhea/constipation
- GI bleeding
Severe(common in immunocompromised)
- Chronic colitis
- Anemia
- Chronic diarrhea; wt loss
describe the life cycle of wuchereria bancrofti and brugia malayi
L3 are introduced to blood by mosquito
adults develop and reside in lymphatics
adults make sheathed microfilariae
pathophysiology of hookworm disease
they suck blood
bad for kids and pregos, especially w/high worm burden
1 worm can take .1ml of blood a day; that adds up
anemia, malnutrition. BAD
life cycle/transmission for strongyloides stercoralis
free-living cycle
- rhabditiform larvae passed in stool; develop into adults and after several lineages, infective filariform develops
parasitic cycle
- filariform attach to feet(like hookworm) and head to lungs
-
swallowed; mature in small intestine to male/femal forms
- make eggs which yeild rhabditiform larvae:
- become filariform which auto-infect via lungs
- pass in stool to progress in free-living cycle
- make eggs which yeild rhabditiform larvae:
hookworm life cycle and transmission
filariform attach to foot/leg and move into bloodstream
penetrate lungs and swallow into small intestine
adults attach to intstinal wall, suck blood, pass eggs in feces
eggs passed in still hatch, develop into filariform, search for more humans
