Helminths Infections Flashcards
What makes up the platyhelminthes + are they m/f
Trematodes (flukes)
cestodes (tapewoms, segmented)
-Hermaphrodites (except schistomes)
What makes up namathelminthes + are they m/f
Just namathelminthes (round worms) - male and femal varieties
General trematodes- DH, IH
humans (DH) freshwater snails (IH)
Fasicola Hepatica (Liver trematode)- DH, IH, transmissoon, habitat
DH- man
IH- snails
transmission- ingesting water vegetation
Habitat- biliary ducts
Fascicola hepatica (liver trematode)- acute/chronic stages
acute-symptoms can occur as a result of the parasite’s migration from the intestine to and through the liver (nausea, vomiting, and abdominal pain/tenderness).
çhronic- settle in bile duct + cause blickage, pain in right upper quadrent
What is the main type of blood fluke (and subspecies)
Schistosoma- S mansoni
Life cycle of s mansoni
- Eggs passed in urine or stool
- Eggs contaminate freshwater
- eggs hatch in to miracidium
- Special types of snails’ vessels
- Infective stage:Cercaria
- Penetrate the human skin
- Enter blood vessels
What body organ does s mansoni target
Mesenteric veins (remember same m)
Schistosomiasis- Clinical picture
Swimmers itch initially at site
-fever, abdominal pain etc
then will have damage to intestinal wall, urinary bladder which will cause gatro hemorrhage etc etc
Lung fluke life cycle- IH, DH, habitat
IH- freshwater snail + crustacean
DH- Ingestig inadequetly cooked crustacean
Traves thru abdominal wall to lung
Clinical picture of lung fluke
- Bleeding in alveli, coughing w blood in sputum
- pleurtitic chest pain, bac pneumonia
Where do adults and larvea of tapeworms(cestodes) live
Adults- lumen of small intestine
Larvae- live in tissues
When can pork taeniasis (pork tapeworm) be serious
If eggs are ingestied by humans- can causes cysts in CNS where it can cause seizures etc
What is the tapeworm that usually infects dogs but can accidentally infect humans upon ingesting eggs from dogs
Hydatid disease
In humans will causes cysts (especially in liver)
What are the 2 nematodes of the large instestine
- Enterobius vermiculars (pin worm)
2. trichuris trichuria (whip worm)
Enterobius vermicularis- life cycle, transmission, disease symtoms
migrates to perianal arae and will scratch area and autoinfect
Enterobiasis- asymptomatic perianal pruritus at night
Trichuris trichuria (whip worm)- disease and symtoms
trichuriasis
-Virulent and aggressive in heavy infections causing mucosal bleeding and painful passage of stooland Rectal prolapse.
What are the 3 small intestinal nematodes
- Ascaris lumbricoides
- Ancylostoma & Necator (Hook Worm)
- Strongyloides stercoralis
Ascaris lumbricoides- transmission, 2 phases
Swallowing infective eggs
- Pulmonary phase- The larvae mature in the lungs → penetrate the alveolar walls → ascend the bronchial tree to the throat and are swallowed. (transient respiratory symptoms)
- Intestinal phase- results in diareeaha, obstruction of intestinal lumen
Hook worm 3 phases
- cutaneous phase- penetrates skin, causes itch
- Migratory phase (matures in lung)
- Intestinal- Diarrhea, intestinal ulcers
How does strongyloidiasis differ and similar to hook work
same lifecycle
-passes larveae in feces that may cause autoinfection
What are the 2 tissue nematodes that are caused by larvea
Toxocariasis
Trichinella spiralis
What is the tissue nematode that is caused by the adult form of the nematode
Filariasis
Toxocariasis in humans
The human is the accidental host.
→ If the human accidentally ingests eggs there will be an abnormal life cycle
of this parasite. The eggs will hatch, and the larvae will migrate into liver lung/ other tissues and cause cysts
How is trichinella spiralis transmitted and pathogenesis/ symptoms
Eating insufficiently cooked pork
-Larvea migrate to striated mm and cysts form
Have trouble coordinating mvts, heart conditions
Two types of filarsiasis
Lymphatic
Onchocerciasis
Lymphatic filariasis- vector and symptoms
Mosquito vector
elephantitis
Onchocerciasis- vector and disease
Black fly vector
river blindness
