Tissue Nematodes Flashcards
In which class is Trichinella spiralis classified?
Adenophorea
What is characteristic of Trichinella spiralis’ esophagus?
long = 2/3 of body length: anterior is thin walled & muscular vs. posterior is surrounded by stichocytes (granular cells w/ digestive enzymes)
What is the stichosome and what does it secrete?
posterior to esophagus & stichocytes. secretes?
Where do adult Trichinella spiralis’ live in the host?
small intestine
Explain how one host ind is the DH & IH in the life cycle of Trichinella spiralis.
female produces L1 not eggs
What does ovoviviparous mean?
produces L1 not eggs
What type of cells do Trichinella spiralis L1 penetrate once they have left the SI?
skeletal muscle fibers & induce change in muscle
What changes occur in a host cell during its transformation into a nurse cell in Trichinella spiralis?
- loses myofilaments 2. nuclei hypertraply 3. mitochondria degenerate 4. circulatory rate - network of capillaries
What symptoms might the host experience during nurse cell transformation in Trichinella spiralis infection?
muscle pain
Compare sylvatic & urban trichinellosis.
sylvatic: wild carnivores & prey vs. urban: farms, rats & pigs, pigs eat rats and humans eat pigs
What are the 3 phases of Trichinella spiralis pathology?
- intestinal phase 2. migration phase 3. inflammatory phase
What happens during the intestinal phase of Trichinella spiralis?
mild: lesions in intestinal lining, nausea, fever, diarrhea, pain
What happens during the migration phase of Trichinella spiralis?
severe (L1s): eye tongue, diaphragm, jaw, chewing, swallowing all have muscle pain. difficultly breathing, chewing, swallowing
What happens during the inflammatory phase of Trichinella spiralis?
moderate: nurse cells, strong immune response, heart damage & nervous disorder
How is infection with Trichinella spiralis diagnosed?
ELISA: 1. antibodies produced against parastie 2. antigen from stichocytes
What is ESA and where is it produced?
excretory secretory antigen from stichocytes
How should Trichinella spiralis infection be treated?
albendazole, metbendazole for adult worms. worms don’t live long
What populations are most at risk of Trichinella spiralis infection?
people eating undercooked wild game
Does cooking or freezing meat control Trichinella spiralis infection?
yes: cook at 170F or freeze at 5F for 21 days
What is the normal DH in the Anisakis life cycle?
marine mammals
What are the IHs for Anisakis and what stages develop in each host?
1st IH: crustanceans 2nd IH: fish with L3
How do humans become involved in Anisakis life cycle?
ingest raw/undercooked fish with L3
What pathology can result if a human is infected with Anisakis?
- acute - intense pain, nausea, vomiting 2. chronic - abescesses, granduloma (host response)
How is Anisakis diagnosed in humans?
ELISA
What does ELISA detect?
circulting antigen
Why doesn’t ELISA detect antibodies?
detects parasite secretions from invasion into host tissue
How is Anisakis infection treated and prevented?
treatment: self limiting, surgery, albendazole control: candling, cook/freeze meat
In which class is Dracunculus medinensis classified?
secermenteo
What is the common name of Dracunculus medinensis?
guinea worm, firery serpent
How is Dracunculus medinensis transmitted?
L1 is eating by copepod L3 infects humans when they drink infected water
Where does the female Dracunculus medinensis live?
skin of humans host
Where does female Dracunculus medinensis lay eggs?
subcutaneous tissues of infected humans
What causes Dracunculus medinensis blister to form?
immune response by host
How do Dracunculus medinensis L1s leave the host?
water causes blister to rupture and L1s enter the water
What is the IH in Dracunculus medinensis?
copepods
Where do the Dracunculus medinensis adults live?
skin of legs
Describe the pathology caused by Dracunculus medinensis.
- migration - immune rxn to parasite waters 2. blister - secondary infection 3. non emergent worms, didn’t make it to skin die & calcified in or near joints and cause arthritis
How is Dracunculus medinensis infection diagnosed and treated?
diagnosed: blister with worm treatment: small stick to wind worm: Caduceus
In what parts of the world is Dracunculus medinensis found?
areas with drought because water is concentrated
Does eradication of Dracunculus medinensis seem possible?
yes: projected to be 1st parasite and 3rd disease to be eradicated
What is the Carter Center doing in the fight against Dracunculus medinensis?
- education 2. treat ponds w chemicals (temephos) 3. funding and gov assistance 4. water wells 5. filter clothes 6. medical supplies 7. pipe filters
What is the parasitologist’s dilemma?
eradication of parasite may lead to lower host death rate but if this is not matched with lower birth rate -> consequences to quality of life
