Parasitology: Metazoa Flashcards
What are the metazoa subdivisions?
- Nemathelminthes (roundworms)
- Platyhelminthes (flatworms)
What are the subdivisions of Nemathelminthes + Platyhelminthes
Nemathelminthes
- Intestinal
- Blood/tissue
Platyhelminthes
- Cestodes “tape worms”
- Trematodes “flukes”
What are the intestinal nemathelminthes?
- Strongylodes Stercoralis
- Enterobius Vermicularis
- Trichuris Trichiura
- Ascaris Lubricoides
- Necter Americans + Ancylostoma Duadenale
Enterobius Vermicularis details
- “seatworm”
- Perianal puritis = itchy butt
- Scotch tape on butt crack pick up the ova –> used to diagnose (looks like a contact lens)
- Children get this from fomites + people-people contact
Trichuris Trichiura details
- “whipworm”
- Tropical climates
- Stool –> ova (looks like a FOOTBALL) = Diagnostic
- Get sick by ingesting ova (fec-oral)
Ascaris Lumbricoides details
- “roundworm of man”
- most common helminth infection WORLDWIDE
- stool –> ova
- Fec-oral
- Adult worms mature in the lungs –> get swallowed and you puke them out sometimes
- Have either 1) Corticated ova (have mammilated coat) or 2) Decorticated ova
Necter Americans + Ancylostoma Duadenale details
- “hookworm”
- Africa, Caribbean, latin america
- LARVA PENTRATES SKIN
- Cause severe nutritional deficiencies
- stool –> ova = diagnostic
- Rhabditiform = Larva
- Filariform = Infective, non-feeding: penetrates skin
- Males have copulatory bursa
- AD: males have teeth
Strongylodes Stercoralis details
- “threadworm”
- Tropic and subtropic
- LARVA PENTRATES SKIN
- stool –> LARVA = diagnostic
- Rhabditiform = Active feeding + has genital premordium
What parasites types are found in blood/tissues?
1) Filariae
- Wuchereria bancrofti
- Brugia malayi
- Loa loa
- Onchocerca volvulums
- Mansonella species
2) Trichinella Spirals
- Toxocara
- Dracunculus medinensis
Filariae details
- Tropic + subtropic
- Insect vectors
1) Microfilariae (blood smear = evaluation)
2) Filariae (adult worm)
Trichinella Spirals details
- Found in muscles
- Undercooked pork –> larva goes through intestinal mucosa of small intestine –> encyst into striated muscle fibers
- Found in muscle biopsy
What are the cestodes?
- AKA “tapeworms”
- Taenia saginata - “beefworm”
- Taenia solium - “porkworm”
- Diphyllobothrium latum
- Echinococcus granulosus
Taenia saginata + Taenia solium details (similarities)
- Stool –> eggs or proglottids = diagnostic
- Eggs have radial striations
- Scolex (head) has 4 suckers
- Proglottids = section of adult worm
Taenia saginata + Taenia solium details (differences)
- Solium: goes in BRAIN tissue –> neurocysticercosis
- Solium: Scolex has a crown-looking thing called ROSTELLUM HOOKS
Taenia saginata + Taenia solium life-cycle
1) Cysticerus in cow or pig
2) Human eats undercooked cow/pig and the cysticerus –> adult worm in the intestines
3) Proglottides are passed in feces
4) Adult worms produce eggs
5a) Cow/pig eats eggs –> cysticerus forms in their muscle … cycle repeats
5b) SOLIUM ONLY: human eats eggs
6) Eggs –> cysticerus forms in brain
